document_title: Timeline for the day of the September 11 attacks

question_text: what time was it when the first plane hit the twin towers

question_tokens: what time was it when the first plane hit the twin towers

text: Timeline for the day of the September 11 attacks

text: Major events[edit]

text: 7:59 a.m.: American Airlines Flight 11, a Boeing 767 carrying 81 passengers and 11 crew members, departs 14 minutes late from Logan International Airport in Boston, bound for Los Angeles International Airport. Five hijackers are aboard.

text: 8:14: United Airlines Flight 175, a Boeing 767, carrying 56 passengers and nine crew members, departs 14 minutes late from Logan International Airport in Boston, bound for Los Angeles International Airport. Five hijackers are aboard.

text: 8:14: Flight 11 is hijacked over central Massachusetts, turning southwest.

text: 8:20: American Airlines Flight 77, a Boeing 757 with 58 passengers and six crew members, departs 10 minutes late from Washington Dulles International Airport, for Los Angeles International Airport. Five hijackers are aboard.

text: 8:42: United Airlines Flight 93, a Boeing 757 with 37 passengers and seven crew members, departs 42 minutes late from Newark International Airport, bound for San Francisco International Airport. Four hijackers are aboard.

text: 8:42–8:46 (approx.): Flight 175 is hijacked above Albany, New York, about 140 miles north of New York City, turning south.

text: 8:46:40: Flight 11 crashes into the north face of the North Tower (1 WTC) of the World Trade Center, between floors 93 and 99. The aircraft enters the tower intact.

text: 8:50–8:54 (approx.): Flight 77 is hijacked above southern Ohio, turning to the southeast.

text: 9:03:00: Flight 175 crashes into the south face of the South Tower (2 WTC) of the World Trade Center, between floors 77 and 85. Parts of the plane, including the starboard engine, leave the building from its east and north sides, falling to the ground six blocks away.

text: 9:28: Flight 93 is hijacked above northern Ohio, turning to the southeast.

text: 9:37:46: Flight 77 crashes into the western side of The Pentagon and starts a violent fire.

text: 9:45: United States airspace is shut down.

text: 9:59:00: The South Tower of the World Trade Center collapses, 56 minutes after the impact of Flight 175.

text: 10:03:11: Flight 93 is crashed by its hijackers and passengers, due to fighting in the cockpit 80 miles (129 km) southeast of Pittsburgh in Somerset County, Pennsylvania. Later reports indicate that passengers had learned about the World Trade Center and Pentagon crashes and were resisting the hijackers. The 9/11 Commission believed that Flight 93's target was either the United States Capitol building or the White House in Washington, D.C.

text: 10:28:22: The North Tower of the World Trade Center collapses, 1 hour, 42 minutes after the impact of Flight 11. The Marriott Hotel, located at the base of the two towers, is also destroyed.

text: 10:50:19: Five stories of part of the Pentagon collapse due to the fire.

text: 5:20:33 p.m.: 7 World Trade Center, a 47-story building, collapses.

text: Significant events[edit]

text: 6:00 a.m.[edit]

text: 6:00: Mohamed Atta and Abdulaziz al-Omari travel Colgan Air Flight 5930 from Portland International Jetport in Portland, Maine, to Logan International Airport in Boston, Massachusetts.[1]

text: 6:45: Atta and al-Omari arrive at Logan International Airport.[1]

text: 6:52: Marwan al-Shehhi calls Atta from another terminal at Logan to confirm that the plans for the attack are set.[1]

text: 7:00 a.m.[edit]

text: 7:35: Atta and al-Omari board American Airlines Flight 11.[2]

text: 7:40: The rest of the Flight 11 hijackers board the airplane.

text: 7:59: Flight 11, a Boeing 767 carrying 81 passengers and 11 crew members, departs 14 minutes late from Logan International Airport in Boston, its destination being Los Angeles International Airport (LAX) in Los Angeles County, California.[3]

text: 8:00 a.m.[edit]

text: 8:13: Flight 11 has its last routine communication with the Federal Aviation Administration's (FAA's) Boston Center.[4]

text: 8:14: Flight 11 is hijacked when hijackers Waleed and Wail al-Shehri rise from seats 2A and 2B and stab two flight attendants. Atta rises from seat 8D and approaches the cockpit. Within minutes, he is at the controls.

text: 8:14: United Airlines Flight 175, another fully fueled Boeing 767, carrying 56 passengers and nine crew members, also departs from Logan International Airport in Boston; its destination was also Los Angeles International Airport. Five hijackers are aboard. One of them communicated with Mohammed Atta shortly before American Airlines Flight 11's takeoff.[4]

text: 8:19: Betty Ong, a flight attendant on Flight 11 alerts American Airlines via an airphone: "The cockpit is not answering, somebody’s stabbed in business class—and I think there’s Mace—that we can’t breathe—I don’t know, I think we’re getting hijacked." She then tells of the stabbings of two flight attendants.[4]

text: 8:20: The FAA's Boston Center flight controllers decide that Flight 11 has probably been hijacked.

text: 8:20: American Airlines Flight 77, a Boeing 757 with 58 passengers and six crew members, departs from Washington Dulles International Airport in Fairfax and Loudoun Counties, Virginia, for Los Angeles International Airport. Five hijackers are aboard.

text: 8:21: Flight 11's transponder signal is turned off, but can still be tracked via primary radar by Boston Center. (Prior to the 9/11 Commission's report, news organizations reported this time as 8:13 or immediately thereafter.)

text: 8:24: A radio transmission comes from Flight 11: "Eh..... We have some planes. Just stay quiet, and you'll be okay. We are returning to the airport." It is believed Atta mistakenly held a button directing his voice to radio rather than to the plane's cabin as he intended. A few seconds later, Atta's voice says, "Nobody move. Everything will be okay. If you try to make any moves, you'll endanger yourself and the airplane. Just stay quiet." Air traffic controllers hear the transmission.

text: 8:25: Boston Center flight controllers alert other flight control centers regarding Flight 11. The North American Aerospace Defense Command (NORAD) is not yet alerted.

text: 8:26:30: Flight 11 makes a 100-degree turn to the south, heading toward New York City.[5]

text: 8:34: A third transmission from Flight 11: "Nobody move please. We are going back to the airport. Don't try to make any stupid moves."

text: 8:34: Dan Bueno from Boston Center notifies the tower controller at Otis Air National Guard Base at Cape Cod of the hijacking of Flight 11. The controller directs Bueno to contact Northeast Air Defense Sector (NEADS), the northeast sector of NORAD.[6] The controller then notifies Otis Operations Center that a call from NEADS might be coming.[7] Two F-15 pilots begin to suit up.[8]

text: 8:37: Flight 175 confirms sighting of hijacked Flight 11 to flight controllers, 10 miles (16 km) to its south.

text: 8:37:52: Boston Center control notifies NEADS of the hijacking of Flight 11, the first notification received by NORAD that Flight 11 had been hijacked. The controller requests military help to intercept the jetliner.

text: 8:41: The FAA's New York Center requests information about Flight 11 over the radio. Flight 175 responds: "[...]ah we heard a suspicious transmission on our departure out of Boston ah with someone ah, ah sound like someone sound like someone keyed the mike and said ah 'everyone ah stay in your seats'".[9] New York Center acknowledges and says it will pass the information on.

text: 8:42: United Airlines Flight 93, a Boeing 757, takes off with 37 passengers and seven crew members from Newark International Airport (now Newark Liberty International Airport), bound for San Francisco International Airport, following a 40-minute delay due to congested runways. Four hijackers are aboard. Its flight path initially takes it close to the World Trade Center, which is 4 minutes away from being struck, before moving away westwards.

text: 8:42–8:46 (approx.): Flight 175 is hijacked.

text: 8:44: Flight attendant Amy Sweeney, aboard Flight 11, reports by telephone to Michael Woodward at the American Airlines Flight Services Office in Dallas, "Something is wrong. We are in a rapid descent... we are all over the place." A minute later, Woodward asks her to "describe what she sees out the window". She responds, "I see the water. I see the buildings. I see buildings..." After a short pause, she reports, "We are flying low. We are flying very, very low. We are flying way too low." Seconds later she says, "Oh my God, we are way too low." The call ends with a burst of very loud, sustained static.

text: 8:46: Two F-15 fighter jets are ordered to scramble from Otis Air National Guard Base in Massachusetts, intended to intercept Flight 11. Because Flight 11's transponder is off, the pilots do not know the location of their target. NEADS spends the next several minutes watching their radar screens in anticipation of Flight 11 returning a radar contact.

text: 8:46:40:[10] Flight 11 crashes at roughly 466 mph (790 km/h or 219 m/s or 425 knots) into the north face of the North Tower (1 WTC) of the World Trade Center, between floors 93 and 99. The aircraft enters the tower intact. It plows to the building's core, severing all three gypsum-encased stairwells, dragging combustibles with it. A powerful shock wave travels down to the ground and up again. The combustibles and the remnants of the aircraft are ignited by the burning fuel. As the building lacks a traditional full cage frame and depends almost entirely on the strength of a narrow structural core running up the center, fire at the center of the impact zone is in a position to compromise the integrity of all internal columns. People below the severed stairwells start to evacuate, but no one above the impact zone is able to do so.

text: BBC correspondent Stephen Evans was sitting in the foyer of the South Tower and described hearing a "huge bang" like "like somebody dropped a skip full of rubbish" followed by "two or three similar huge explosions". The South Tower shook.[11] French filmmakers Jules and Gedeon Naudet and Czech immigrant Pavel Hlava videotape the crash of Flight 11 with their video cameras from different locations. A WNYW TV camera records the sound, but not the image, of the crash.

text: 8:46:43: Chief of the New York City Fire Department's 1st Battalion, Joseph Pfeifer, makes the first fire department radio message advising the FDNY Manhattan Fire Dispatch Office of the crash. Chief Pfeifer and personnel from other fire companies were several blocks north, on the corner of Church Street and Lispenard Street investigating an odor of gas in the street, and witnessed the attack, along with Jules Naudet, who was accompanying the firefighters at the time:

text: Battalion 1 Chief (Chief Pfeifer): "Battalion 1 to Manhattan."

text: Manhattan Dispatch: "Battalion 1, k."

text: Battalion 1 Chief (Chief Pfeifer): "We just had a plane crash into the upper floor of the World Trade Center. Transmit a 2nd Alarm and start re-located companies into the area."

text: Manhattan Dispatch: "10-4 [message received], Battalion 1."

text: 8:48–10:28: At least 100 people (some accounts say as many as 250), primarily in the North Tower, trapped by fire and smoke in the upper floors, jump to their deaths.[citation needed] One person at street level, firefighter Daniel Suhr, is hit by a jumper and dies.[12] No form of airborne evacuation is attempted as smoke is too dense for a successful landing on the roof of either tower and New York City lacked helicopters equipped for horizontal rescue.

text: 8:48:08: The first television report of an incident at the World Trade Center is broadcast locally in New York by WNYW less than two minutes after the plane crashed into the North Tower. WNYW breaks into a Paramount Pictures movie trailer for Zoolander with the first live TV pictures of black smoke coming from the North Tower, relayed by a WNYW cameraman at ground level.[13] One of the station's camera crews already had been out on the street that morning for New York's mayoral primary election. As WNYW broadcasts the first live pictures of smoke, the voice of reporter Dick Oliver is heard from the scene:

text:
“
Jim [referring to WNYW's Jim Ryan, who was not in the studio at the time], just a few moments ago, something believed to be a plane crashed into the South Tower of the World Trade Center. I just saw flames inside, you can see the smoke coming out of the tower; we have no idea what it was. It was a tremendous boom just a few moments ago. You can hear around me emergency vehicles heading towards the scene. Now this could have been an aircraft or it could have been something internal. It appears to be something coming from the outside, due to the nature of the opening on about the 100th floor of the South Tower of the World Trade Center.
”

text: Three minutes later, Jim Ryan corrected the location of the first plane crash from the South Tower to the North Tower.

text: 8:48:29: The first radio report of the incident is heard on WCBS-AM through traffic reporter Tom Kaminski. WCBS' traffic reports are delivered every ten minutes "on the 8s", meaning that Kaminski's traffic report was to come within two minutes of the initial impact of Flight 11 (although there is no record of how much time actually passed). At the time Kaminski was in "Chopper 880", WCBS' helicopter that he reports from for morning and evening rush hour traffic reports. The following consists of WCBS anchor Pat Carroll crossing to Kaminski in the chopper before he files his report.

text:
“
Pat Carroll: WCBS news time, 8:48, it's traffic and weather together sponsored by Henry Miller's Theatre. Tom Kaminski, Chopper 880.
Tom Kaminski: Alright uh, Pat, we are just currently getting a look...at the World Trade Center, We have something that has happened here at the World Trade Center. We noticed flame and an awful lot of smoke from one of the towers of the World Trade Center. We are just coming up on this scene, this is easily three-quarters of the way up...we are...this is...whatever has occurred has just occurred, uh, within minutes and, uh, we are trying to determine exactly what that is. But currently we have a lot of smoke at the top of the towers of the World Trade Center, we will keep you posted.
”

text: 8:49:34: The first network television and radio reports of an explosion or incident at the World Trade Center. CNN breaks into a Ditech commercial at 8:49. The CNN screen subtitle first reads "WORLD TRADE CENTER DISASTER." Carol Lin, the first TV network anchor to break the news of the attacks, says:

text:
“
This just in. You are looking at obviously a very disturbing live shot there. That is the World Trade Center, and we have unconfirmed reports this morning that a plane has crashed into one of the towers of the World Trade Center. CNN Center right now is just beginning to work on this story, obviously calling our sources and trying to figure out exactly what happened, but clearly something relatively devastating happening this morning there on the south end of the island of Manhattan. That is once again, a picture of one of the towers of the World Trade Center.
”

text: Just a minute later, Sean Murtagh, CNN vice-president of finance, in an on-air phone call, says from his office in the CNN New York bureau that a large passenger commercial jet was seen to hit the World Trade Center. Murtagh is the first network employee on the air. The first email bulletins of breaking news from CNN and MSNBC report "fire at tower of World Trade Center". Both CNN and MSNBC's websites receive such heavy traffic that many servers collapse. BBC News' website is active and shows a picture of the North Tower on fire. Minutes later, email news bulletins revise the reports of fire to a plane crash.

text: 8:50: NEADS is notified that a plane has struck the World Trade Center as they continue to try to locate the flight on radar.

text: 8:50: ABC News was airing Good Morning America at the time of the attack. After returning from a commercial break, hosts Charles Gibson and Diane Sawyer made the announcement of the first plane that hit the North Tower.

text: 8:50: CNBC interrupts an episode of Squawk Box hosted by Mark Haines with a report of the unfolding attack.[14]

text: 8:50–8:54 (approx.): Flight 77 is hijacked.

text: 8:51: Matt Lauer, co-host of NBC News' Today, interrupts an interview with author Richard Hack and says to the audience, "We wanna go live right now, and show you a picture of the World Trade Center...there is a breaking story..." However, NBC did not immediately have the picture ready and went to a regularly scheduled commercial break. They return with a shot of the burning tower. Programming is also interrupted on MSNBC.[citation needed]

text: 8:51: A flight controller at the FAA's New York Center notices that Flight 175 had changed its transponder code twice four minutes earlier; he tries to contact the flight.

text: 8:51: New York City's Amateur Radio Emergency Service net is activated, with ham operators in the area assisting with emergency communications.[15]

text: 8:51:34: WINS-AM interrupts its 8:51 traffic report and anchor James Faherty relays word of the crash of Flight 11 to the listening audience, with the station having been notified by one of its employees who lives near the site.

text: 8:52: Lee Hanson receives a phone call from his son, Peter, a passenger on United 175, who says: "I think they've taken over the cockpit—an attendant has been stabbed—and someone else up front may have been killed. The plane is making strange moves. Call United Airlines—tell them it's Flight 175, Boston to LA." Also on board Flight 175, a flight attendant calls a United Airlines office in Chicago, reporting that the flight had been hijacked, both pilots had been killed, a flight attendant had been stabbed, and the hijackers were probably flying the plane.[16]

text: 8:52: The F-15s at Otis Air National Guard Base are airborne. Still lacking an intercept vector to Flight 11 (and not aware that it has already crashed), they are sent to military controlled airspace off Long Island and ordered to remain in a holding pattern until between 9:09 and 9:13.

text: 8:52: CBS interrupts The Early Show to report the news of the attack. Bryant Gumbel makes the announcement that a plane has crashed into the World Trade Center.

text: 8:52: CBC Newsworld anchor Mark Kelley makes the first Canadian television report of the first plane crash.

text: 8:54: Flight 77 deviates from its assigned course, turning south over Ohio.

text: 8:55: Fox News comes back from a commercial break to report the attack. E. D. Hill informs viewers that a plane crashed into the North Tower.

text: 8:55 (approx.): An announcement is made over the building-wide PA system by officials in the still-undamaged South Tower of the World Trade Center, "The building is secure, please return to your desks."[17] This announcement is reacted to in numerous ways, ranging from people going back to their offices as suggested, ignoring it and evacuating anyway, or congregating in common areas such as the 78th floor sky lobby.

text: 8:55: President George W. Bush arrives at Emma E. Booker Elementary School in Sarasota, Florida, as part of a scheduled visit to promote education when White House Chief of Staff Andrew Card, who is with Bush, informs him that a small twin-engine plane has crashed into the World Trade Center. Before entering the classroom, the President speaks to National Security Advisor Condoleezza Rice, who is at the White House. She first tells him it was a twin-engine aircraft—and then a commercial aircraft—that had struck the World Trade Center, adding "that’s all we know right now, Mr. President."[18]

text: 8:56: Ten minutes after the North Tower of the World Trade Center was hit by Flight 11, the transponder on Flight 77 is turned off and even primary radar contact with the aircraft is lost. During radar blackout Flight 77 turns east, unnoticed by flight controllers. When primary radar information is restored at 9:05, controllers searching for Flight 77 to the west of its previous position are unable to find it.[19] Flight 77 travels undetected for 36 minutes on a course heading due east toward Washington, D.C.

text: 8:58: Flight 175 takes a heading toward New York City.

text: 9:00 a.m.[edit]

text: 9:00: Lee Hanson receives a second call from his son Peter, aboard Flight 175: "It's getting bad, Dad. A stewardess was stabbed. They seem to have knives and Mace. They said they have a bomb. It's getting very bad on the plane. Passengers are throwing up and getting sick. The plane is making jerky movements. I don't think the pilot is flying the plane. I think we are going down. I think they intend to go to Chicago or someplace and fly into a building. Don't worry, Dad. If it happens, it'll be very fast. My God, my God." The call ends abruptly, as Lee Hanson hears a woman scream.[16]

text: 9:01–9:02: A manager from the FAA's New York Center tells the Air Traffic Control System Command Center in Herndon, Virginia: "We have several situations going on here. It's escalating big, big time. We need to get the military involved with us... We're, we're involved with something else, we have other aircraft that may have a similar situation going on here."

text: 9:01: FAA's New York Center contacts New York terminal approach control and asks for help in locating Flight 175.

text: 9:02: Evacuation of both World Trade Center towers is ordered by FDNY Battalion Chief Joseph Pfeifer, who was stationed in the lobby of the North Tower. Although it is uncertain whether the South Tower's deputy fire safety director receives this order, an announcement is made over the tower's PA system to "begin an orderly evacuation if conditions warranted".[20]

text: 9:03:00: Flight 175 crashes at about 590 mph (950 km/h, 264 m/s or 513 knots) into the south face of the South Tower (2 WTC) of the World Trade Center, between floors 77 and 85.[21] All 65 people on board the aircraft die instantly on impact, and unknown hundreds in the building as well. By this time, several media organizations, including the three major broadcast networks (who have interrupted their morning shows), are covering the first plane crash—millions see the impact live. Parts of the plane, including the starboard engine, leave the building from its east and north sides, falling to the ground six blocks away.

text: A massive evacuation begins in the South Tower below its impact zone. One of the stairwells in the South Tower remains unblocked from the top to the bottom of the tower because of the plane hitting at an offset from the vertical center line of the building, but it is filled with smoke. This leads many people to mistakenly go upwards towards the roof for a rooftop rescue that never comes. The Port Authority of New York and New Jersey kept the two sets of heavy metal doors leading to the building's only roof exit tightly locked.[22] The impact severs communication with several television and radio broadcast towers at the WTC; local station WPIX's satellite feed freezes on an image of the second impact which is all the station broadcasts until alternate transmitters are set up hours later.

text: Because of the North Tower's obstruction of the South Tower from certain camera angles, some are originally unaware that a second plane has struck the South Tower, and instead mistakenly believe that the second explosion has occurred in the North Tower. As instant replays of the second plane crash are shown, the anchors on the three major broadcast networks speculate on whether they are witnessing a terrorist attack or some sort of very rare accident. CNN changes its headline to read "Second plane crashes into World Trade Center." On the local station WABC-TV (which CNN was simulcasting at that moment), anchor Steve Bartelstein first assumes that the explosion seen was caused when the fuselage of the first plane exploded. As he first views videotape footage showing that it was actually a plane that had hit the South Tower, the WABC anchor then initially suggests it was a rare accident, saying that the two crashes might have been caused by navigational system failure.

text: Several eyewitness accounts and camera footage reveal that the plane was coming in at an angle, and was seen to turn drastically to the left to be able to hit the tower, unlike its predecessor, Flight 11, which had been able to hit the North Tower straight on. Thus, it is believed that had the plane continued flying straight, it would have at least simply clipped the side of the building with its left wing, or even missed the building entirely. (Flight 175 came in from the southwest, apparently heading for the Empire State Building, but turned right, then left into the South Tower.)[citation needed]

text: 9:03: President Bush enters a classroom as part of his school visit.

text: 9:03: FAA's New York Center notifies NORAD (NEADS) of the hijacking of Flight 175, at the same time it crashes.

text: 9:04: Fox News Channel anchor Jon Scott mentions Osama bin Laden as a possible suspect.

text: 9:04 (approximately): The FAA's Boston Air Route Traffic Control Center stops all departures from airports in its jurisdiction (New England and eastern New York State).

text: 9:05: After brief introductions to the Booker elementary students, President Bush is about to begin reading The Pet Goat with the students when Chief of Staff Andrew Card interrupts to whisper to the president, "A second plane has hit the second tower. America is under attack."[23] The president stated later that he decided to continue the lesson rather than alarm the students.

text: 9:06: The FAA bans takeoffs of all flights bound to or through the airspace of New York Center from airports in that Center and the three adjacent Centers—Boston, Cleveland, and Washington. This is referred to as a First Tier groundstop and covers the Northeast from North Carolina north and as far west as eastern Michigan.

text: 9:08: The FAA bans all takeoffs nationwide for flights going to or through New York Center airspace. ABC News reports later that the Port Authority of New York and New Jersey, the agency that runs the New York-area airports, asked the FAA for permission to close down the New York Center airspace.

text: 9:11: The last PATH train leaves the World Trade Center. The station was vacant when the towers collapsed.

text: 9:13: The F-15 fighters from Otis Air National Guard Base leave military airspace near Long Island, bound for Manhattan.

text: 9:14: President Bush returns to a holding room commandeered by the Secret Service shortly before 9:15. The holding room contains a telephone, a television showing the news coverage, and several senior staff members. The president speaks to Vice President Dick Cheney, Condoleezza Rice, New York Governor George Pataki, and FBI Director Robert Mueller, and prepares brief remarks.[24]

text: 9:15: NBC News reports unconfirmed statements from employees at United Airlines that an American Airlines aircraft had been hijacked prior to its destruction.

text: 9:17: The FAA closes down all New York City-area airports.[25] The city had initially asked the FAA to close down the airports.

text: 9:17:02: CBS News correspondent Jim Stewart in Washington mentions that in the intelligence community, Osama bin Laden is a probable suspect.

text: 9:18: CNN makes reference to foul play for the first time, stating the FBI was investigating a report of plane hijacking. CNN headline: "AP: Plane was hijacked before crashes".

text: 9:19: United Airlines flight dispatcher Ed Ballinger begins sending warning text messages to his flights: "Beware any cockpit intrusion—Two a/c [aircraft] hit World Trade Center." Because he was sending this warning to his 16 transcontinental flights, this takes several minutes.[26]

text: 9:21: All bridges and tunnels into Manhattan closed.[25]

text: 9:23: Ballinger's warning message is sent to Flight 93, and is received in the cockpit a minute later.[26]

text: 9:24: The FAA notifies NORAD's Northeast Air Defense Sector about the suspected hijacking of Flight 77. The FAA and NORAD establish an open line to discuss Flight 77, and shortly thereafter Flight 93.

text: 9:25: The Otis-based F-15s establish an air patrol over Manhattan.

text: 9:25: A video teleconference begins to be set up in the White House Situation Room, led by Richard A. Clarke, a special assistant to the president, that eventually includes the CIA, the FBI, the departments of State, Justice, and Defense, and the FAA.

text: 9:25: The Associated Press informs CNN that the two plane crashes in the World Trade Center appeared to be an "act of terrorism".

text: 9:26: The FAA bans takeoffs of all civilian aircraft regardless of destination—a national groundstop. All military bases in the United States are ordered to increase threat conditions to Delta status.[citation needed]

text: 9:26: Flight 93's pilot, Jason Dahl, replies to Ballinger's text message, "Ed, confirm latest mesg plz--Jason".[26]

text: 9:26: NBC News correspondent Andrea Mitchell reports to MSNBC anchor Lester Holt that a top U.S. government official informed her that one of the two planes that hit the Twin Towers was an American Airlines 767 from Boston to Los Angeles that was hijacked.

text: 9:28: Hijackers storm the cockpit on Flight 93 and take over the flight. The entry of the hijackers is overheard by flight controllers at Cleveland.

text: 9:29: President Bush makes his first public statements about the attacks, in front of an audience of about 200 teachers and students at the elementary school. He states that he will be going back to Washington. "Today, we've had a national tragedy," he starts. "Two airplanes... have crashed... into the World Trade Center... in an apparent terrorist attack on our country," and leads a moment of silence. No one in the President's traveling party has any information during this time that other aircraft were hijacked or missing.[27]

text: 9:32: A radio transmission from Flight 93 is overheard by flight controllers at Cleveland: "Ladies and gentlemen here... is the captain please sit down... Keep remaining  [sic] sitting. We have a bomb on board. So sit."

text: 9:32: Controllers at the Dulles Terminal Radar Approach Control in Virginia observe "a primary radar target tracking eastbound at a high rate of speed", referring to Flight 77.

text: 9:33–9:34: A tower supervisor at Reagan National Airport tells Secret Service operations center at the White House that "an aircraft [is] coming at you and not talking with us," referring to Flight 77. The White House is about to be evacuated when the tower reports that Flight 77 has turned and is approaching Reagan National Airport.

text: 9:34: The FAA's Command Center relays information concerning Flight 93 to FAA headquarters.

text: 9:35: The President's motorcade departs from the elementary school, bound for Sarasota–Bradenton International Airport and Air Force One.

text: 9:35: Flight 93 reverses direction over Ohio and starts flying eastwards.

text: 9:35: Based on a report that Flight 77 had turned again and was circling back toward the District of Columbia, the Secret Service orders the immediate evacuation of the Vice President from the White House.

text: 9:36: Cleveland advises the FAA Command Center that it is still tracking Flight 93 and inquires whether someone had requested the military to launch fighter aircraft to intercept the aircraft.

text: 9:37: Vice President Cheney enters an underground tunnel leading to a security bunker.

text: 9:37:46: Flight 77 crashes into the western side of the Pentagon at 530 mph (853 km/h, 237 m/s, or 460 knots) and starts a violent fire. The section of the Pentagon hit consists mainly of newly renovated, unoccupied offices. All 64 people on board are killed, as are 125 Pentagon personnel.

text: 9:39: Another radio transmission is heard from Ziad Jarrah aboard Flight 93: "Uh, this is the captain. I would like you all to remain seated. We have a bomb on board and are going back to the airport, and to have our demands, so please remain quiet."

text: 9:39: Fox News Channel correspondent David Asman reports, "We -- we are hearing -- right now that another explosion that -- has taken place. At the Pentagon."[29]

text: 9:39: NBC News Pentagon correspondent Jim Miklaszewski reports that "...it felt, just a few moments ago, like there was an explosion of some kind here at the Pentagon." NBC and MSNBC relay reports of the explosion but do not relay word of the crash of Flight 77 as they do not know the cause.

text: 9:40: Video teleconference in White House Situation Room begins with the physical security of the President, the White House, and federal agencies. They are not yet aware of the Pentagon crash.

text: 9:40:49: CNN's Breaking News bulletin reads "Reports of fire at Pentagon."

text: 9:42: Senior FAA traffic manager Ben Sliney issues the execution order for SCATANA grounding all air traffic over the United States and diverting any incoming international traffic to alternate destinations.

text: 9:43: Abu Dhabi TV reports it received a call from the Democratic Front for the Liberation of Palestine, claiming responsibility for the World Trade Center attack, but this is soon denied by a senior officer of the group.[30]

text: 9:43: The White House and the Capitol are evacuated and closed.

text: 9:45: United States airspace is shut down. No civilian aircraft are allowed to take off, and all aircraft in flight are ordered to land at the nearest airport as soon as possible. Nearly all international flights headed for the U.S. are redirected to Canada, while some flights from South America were diverted to Mexico. Transport Canada, Canada's transportation agency, also closes down its airspace, but the Mexican airspace did not shut down. The FAA announces that civilian flights are suspended until at least noon September 12, while Transport Canada gives similar orders; the FAA further ordered that diverted U.S.-bound international flights should be taken in, launching the agency's "Operation Yellow Ribbon". The groundings would eventually last until September 14. Military and medical flights as well as Con Air flights continue. This is the fourth time all commercial flights in the U.S. have been stopped, and the first time a suspension was unplanned. All previous suspensions were military-related (Sky Shield I-III), from 1960 to 1962. Many newspapers (including The New York Times) mistakenly print that this is the first time flights have been suspended. This was also the first time commercial flights in Canada have been stopped.

text: 9:45: CNN receives initial reports that, in addition to a fire at the Pentagon, there is also a fire at the National Mall. These reports on the National Mall, however, are later proven to be false.

text: 9:49: The FAA Command Center at Herndon suggests that someone at FAA headquarters should decide whether to request military assistance with Flight 93. Ultimately, the FAA makes no request before it crashes.

text: 9:50 (approximately): The Associated Press reports that Flight 11 was apparently hijacked after departure from Boston's Logan Airport. Within an hour this is confirmed for both Flight 11 and Flight 175.

text: 9:51: FDNY Battalion Chief Orio Palmer of the FDNY's 7th Battalion reaches the 78th Floor Sky Lobby of the South Tower along with Fire Marshal Ronald Bucca. Palmer reports that there are two pockets of fire and numerous dead bodies.[citation needed]

text: 9:52: The National Security Agency intercepts a phone call between a known associate of Osama bin Laden in Afghanistan and someone in the Republic of Georgia, announcing that he had heard "good news", and that another target was still to be hit.[31]

text: 9:53: CNN confirms a plane crash at the Pentagon.

text: 9:55: A CNN correspondent mentions Osama bin Laden as someone determined to strike the US.

text: 9:55: Air Force One leaves Sarasota-Bradenton International Airport.

text: 9:57: Passenger revolt begins on Flight 93.

text: 9:57: President Bush leaves Sarasota, Florida, on Air Force One. The plane reaches cruising altitude and circles for approximately 40 minutes while the destination of the plane is discussed.

text: 9:59:00:[10] The South Tower of the World Trade Center collapses, 56 minutes after the impact of Flight 175. Its destruction is viewed and heard by a vast television and radio audience. As the roar of the collapse goes silent, tremendous gray-white clouds of pulverized concrete and gypsum rush through the streets. Most observers think a new explosion or impact has produced smoke and debris that now obscures the South Tower, but once the wind clears the smoke, it becomes clear that the building is no longer there. ABC News correspondent Don Dahler, who was home at the time of the incident and lived near the site, reports to anchor Peter Jennings on air that he has witnessed the tower collapse; this is perhaps the first broadcast confirmation of the collapse as Dahler's report is filed seconds after the event.

text: 9:59: As the South Tower collapses, Father Mychal Judge, O.F.M., chaplain to the FDNY, is struck by falling debris on the lobby level of the North Tower. He dies of blunt force trauma to the head.[32] He's found by Chief Pfeifer, Jules, and others from the North Tower Command Post who fled when they heard the South Tower collapse and took refuge in the nearby escalator as the debris cloud engulfed them.[33] As Judge's body is the first recovered and certified by the medical examiner's office, he will be designated "Victim 0001" of the September 11 attacks.

text: 10:00 a.m.[edit]

text: 10:00: FDNY Battalion Chief Joseph Pfeifer (inside of the still standing North Tower) orders all FDNY personnel to evacuate, via radio.

text: Battalion 1 Chief (Chief Pfeifer): "Command post, Tower 1, all units. Evacuate the building. Command post, to all units."[34]

text: Due to many communication limitations, numerous firefighters within the tower do not receive this transmission.[35] Some personnel who do not hear the order only leave the building after being told by other firefighters that an evacuation order has been given.[35] Others never receive the order at all.

text: 10:01: The FAA Command Center advises FAA headquarters that an aircraft had seen Flight 93 "waving his wings," the hijackers' efforts to defeat the passengers' counterattack.

text: 10:02: Communicators with the Vice President in the security bunker begin receiving reports from the Secret Service of an inbound aircraft—presumably hijacked—heading toward Washington. This is Flight 93.

text: 10:02: CNN announces that the Sears Tower in Chicago has been evacuated.

text: 10:03 (approximately): The National Military Command Center learns from the White House of Flight 93's hijacking.

text: 10:03:11: United Airlines Flight 93 is crashed by its hijackers and passengers at 583 mph (926 km/h, 272 m/s, or 509 knots), due to fighting in the cockpit 80 miles (129 km) southeast of Pittsburgh in Somerset County, Pennsylvania.[36] Later reports indicate that passengers had learned about the World Trade Center and Pentagon crashes on cell phones and at least three were planning on resisting the hijackers; the resistance was confirmed by Flight 93's cockpit voice recording, on which the hijackers are heard making their decision to down the plane before the passengers succeed in breaching the cockpit door. The 9/11 Commission believed that Flight 93's target was either the United States Capitol building or the White House in Washington, D.C.[37]

text: 10:05: Andrea Mitchell, reporting on NBC from outside the Pentagon, reports that Osama bin Laden may have been involved in the attacks.

text: 10:05: CNN's headlines read: "SOUTH TOWER AT WTC COLLAPSES."

text: 10:05: The IDS Center in Minneapolis is evacuated.

text: 10:07: NBC reports for the first time that the South Tower of the World Trade Center has collapsed. Prior to this time they have said only that a section of the building has fallen away.

text: 10:07: NEADS, controlling the only set of fighters over Washington, first learns of the hijacking of Flight 93, 4 minutes after it actually crashed.

text: 10:08: Air Traffic Control System Command Center in Herndon reports to FAA headquarters that Flight 93 may be down near Johnstown, Pennsylvania; at 10:17 the Command Center concludes it is so.

text: 10:10: Part of the west side of the Pentagon collapses.

text: 10:10: NEADS emphatically tells fighter pilots over Washington, "Negative clearance to shoot."

text: 10:10–10:15 (approximately): Vice President Cheney, unaware that Flight 93 has crashed, authorizes fighter aircraft to engage the inbound plane, reported to be 80 miles (129 km) from Washington, based not on radar (from which it has disappeared) but speed and trajectory projections.

text: 10:13: Thousands are involved in an evacuation of the United Nations complex in New York.

text: 10:13–10:22: The 9/11 Commission's estimated arrival of Flight 93 over Washington had it not crashed in Pennsylvania.[38]

text: 10:14–10:19: A lieutenant colonel at the White House repeatedly relays to the NMCC that the Vice President has confirmed that fighters are cleared to engage inbound aircraft if they can verify that the aircraft was hijacked.

text: 10:15: CNN's headline reads, "EXPLOSION ON CAPITOL HILL."

text: 10:18: NBC reports that Yasser Arafat, Chairman of the Palestine Liberation Organization (PLO), has denied complicity in the attacks and is appalled by them.

text: 10:20: President Bush, aboard Air Force One, tells Vice President Cheney that he has authorized a shootdown of aircraft if necessary.[39]

text: 10:23: The Associated Press reports a car bomb has exploded outside the State Department in Washington, D.C. This and several other reports of terrorist acts in the capital are quickly found to be false.[40]

text: 10:24: Two men who were being evacuated through the underground shopping mall below the South Tower when it collapsed on them are able to climb up through thirty feet of debris to safety. 1010 WINS in New York City reports an explosion at the U.S. Supreme Court building. This is later revealed to be erroneous.[41]

text: 10:28:22:[10] The North Tower of the World Trade Center collapses. Due to the destruction of the gypsum-encased stairwells on the impact floors (most skyscraper stairwells are encased in reinforced concrete), no one who was above the impact zone in the North Tower escapes the collapse. The Marriott Hotel, located at the base of the two towers, is also destroyed. The second collapse is also viewed live on television and heard on radio. The North Tower collapses 1 hour, 42 minutes after the impact of Flight 11—the building had burned during the whole duration of the attacks. 7 World Trade Center burns after the collapse of the North Tower. New York City's 1010 WINS reports the collapse live as it happens, broadcasting a live phone call with a witness.[41] On NBC News, Katie Couric says: "The other tower of the World Trade Center has just collapsed."

text: Several long-distance videos of the collapse, such as CNN, were able to notice that, after the cloud of dust had partially cleared away, a portion of the building was still standing. It appeared to be the lower half of the northwest corner column of the North Tower, which, like a spire, grew larger and had more structure still standing near the bottom. The portion rose to a fairly good height considering the collapse around it, as it appeared to rise nearly forty stories off the ground. This piece remained standing for a few seconds after the initial collapse before it also came down.

text: 10:31: NORAD first communicates the Vice President's shootdown authority to NEADS.

text: 10:35: Air Force One, carrying the President, turns for Barksdale Air Force Base in Bossier City, Louisiana.

text: 10:37: Associated Press reports that officials at the Somerset County airport confirm that a large plane has crashed in western Pennsylvania. CNN's Aaron Brown passes along reports that a 747 is "down" in Pennsylvania. He stresses these reports are unconfirmed. He also, in the confusion, reports another plane heading for the Pentagon. The Mall of America in Bloomington, Minnesota, is evacuated and closed. New York City's 1010 WINS relays a report that the U.S. State Department headquarters in Washington, D.C. has been attacked by a car bomb. This is later reported to be false.[41]

text: 10:39: Another hijacked jumbo jet is claimed to be headed for Washington, D.C. F-15s are scrambled and patrol the airspace above Washington, D.C. while other fighter jets sweep the airspace above New York City. They have orders, first issued by Vice President Cheney and later confirmed by President Bush, to shoot down any potentially dangerous planes that do not comply with orders given to them via radio. Eventually, the aircraft is revealed to be a medevac helicopter on its way to the Pentagon.

text: 10:41: NBC News confirms that a plane has "gone down" in Somerset County. The earlier unconfirmed statements about an incident at the State Department in Washington, D.C. are reported as false.

text: 10:43: CNN reports that a mass evacuation of Washington, D.C., and New York has been started. A few minutes later, New York mayor Rudy Giuliani orders an evacuation of Lower Manhattan.

text: 10:49: Fox News Channel is the first of the United States news networks to implement a news ticker at the bottom of its screen for supplementary information about the attacks. CNN adds one at 11:11, and MSNBC adds one at approximately 2:00 pm. All three cable networks have used a news ticker continuously in the years since (and many local television stations have followed suit).

text: 10:53: New York's primary elections are canceled.

text: 10:53: Defense Secretary Donald Rumsfeld orders the U.S. military placed at DEFCON 3, for the first time since the Yom Kippur War in 1973.

text: 11:00 a.m.[edit]

text: 11:00: Transport Canada halts all aircraft departures until further notice, except for police, military, and humanitarian flights, as part of Operation Yellow Ribbon. The operation was well underway as international flights headed for the U.S. had already started to land at Canadian airports, beginning at CFB Goose Bay. Fourteen other airports follow, including Halifax, Lester B. Pearson in Toronto, Montréal-Dorval, and Vancouver.

text: 11:05: The FAA confirms that several planes have been hijacked in addition to American Airlines Flight 11.

text: 11:16: American Airlines confirms the loss of its two aircraft.

text: 11:26: United Airlines confirms the loss of Flight 93 and states that it is "deeply concerned" about Flight 175.[42]

text: 11:53: United Airlines confirms the loss of its two aircraft.

text: 11:55: The border between the U.S. and Mexico is on highest alert, but is not closed.

text: 12:00 p.m.[edit]

text: 12:01 (approximately): Fourteen people, including twelve firefighters, who were in a section of a stairwell in the North Tower that held together during the collapse, climb the stairs to the top of the Ground Zero rubble field.

text: 12:04: Los Angeles International Airport, the intended destination of Flights 11, 77 and 175, is shut down.

text: 12:15: San Francisco International Airport, the intended destination of Flight 93, is shut down.

text: 12:15 (approximately): The airspace over the 48 contiguous United States is clear of all commercial and private flights.

text: 12:30 (approximately): Secretary of State Colin Powell boards a plane in Lima, Peru, for Washington, D.C.

text: 12:39: On CNN, Senator John McCain (R-AZ) characterizes the attack as an "act of war."

text: 12:41: Senator Orrin Hatch (R-UT) tells CNN, "Both the FBI and our intelligence community believe that this is Bin Laden's signature."

text: 1:00 p.m.[edit]

text: 1:00 (approximately): At the Pentagon, fire crews are still fighting fires. The early response to the attack had been coordinated from the National Military Command Center, but that had to be evacuated when it began to fill with smoke.

text: 1:04: President Bush puts the U.S. military on high alert worldwide (known as Force Protection Condition Delta). Taped remarks from the President were aired from Barksdale Air Force Base, stating that "freedom itself was attacked this morning by a faceless coward and freedom will be defended." He also said that the "United States will hunt down and punish those responsible for these cowardly acts." He then leaves for a U.S. Strategic Command bunker located at Offutt Air Force Base in Bellevue, Nebraska.[43]

text: 1:27: Mayor Anthony A. Williams of Washington, D.C., declares a state of emergency; the District of Columbia National Guard arrives on site.

text: 2:00 p.m.[edit]

text: 2:39: At a press conference New York Mayor Rudy Giuliani is asked to estimate the number of casualties at the World Trade Center. He replies, "More than any of us can bear."

text: 2:50: President Bush arrives at Offutt Air Force Base, Bellevue, Nebraska, to convene a National Security Council teleconference via the U.S. STRATCOM bunker.

text: 3:00 p.m.[edit]

text: 3:00 (approx.): Pasquale Buzzelli, who lost consciousness in a North Tower stairway during the collapse, awakens to find himself lying atop the debris with only a fractured foot.[44][45]

text: 4:00 p.m.[edit]

text: 4:00: National news outlets report that high officials in the federal intelligence community are stating that Osama bin Laden is suspect number one.

text: 4:25: The New York Stock Exchange, NASDAQ, and the American Stock Exchange report that they will remain closed Wednesday, September 12.

text: 4:36: President Bush departs Offutt Air Force Base on Air Force One.

text: 5:00 p.m.[edit]

text: 5:20:27: The east penthouse on top of 7 World Trade Center crumbles apart.

text: 5:20:33: 7 World Trade Center, a 47-story building, collapses. The building contained New York's emergency operations center, operated by the NYC Office of Emergency Management, originally intended to respond to disasters such as the September 11 terrorist attacks. Due to the emergency personnel having more than enough time to evacuate the building since the collapse of the North Tower, there are no injuries or deaths as a result of the collapse.

text: 6:00 p.m.[edit]

text: 6:00: Explosions and tracer fire are reported in Kabul, Afghanistan, by CNN and the BBC. The Northern Alliance, involved in a civil war with the Taliban government, is later reported to have attacked Kabul's airport with helicopter gunships.

text: 6:00: The last of the aircraft headed for the U.S. lands in Canada at Vancouver International Airport, since it was flying over the Pacific.

text: 6:54: U.S. President George W. Bush arrives at the White House in Washington, D.C.

text: 7:00 p.m.[edit]

text: 7:00: Efforts to locate survivors in the rubble that had been the twin towers continue. Fleets of ambulances are lined up to transport the injured to nearby hospitals, but they stand empty. "Ground Zero", as the site of the WTC collapse becomes known henceforth, is the exclusive domain of New York City's Fire Department and Police Department, despite volunteer steel and construction workers who stand ready to move large quantities of debris quickly. Relatives and friends of victims or likely victims, many displaying enlarged photographs of the missing printed on home computer printers, have appeared around New York. The New York Armory at Lexington Avenue and 26th Street and Union Square Park at 14th Street and Broadway become centers of vigil.

text: 7:24: Members of Congress join on the steps of the United States Capitol and sing "God Bless America".[46]

text: 7:30: The U.S. government denies any responsibility for the reported explosions in Kabul, capital of Afghanistan.

text: 8:00 p.m.[edit]

text: 8:00 (approx.): Port Authority Police Officer Will Jimeno, who was in an underground corridor between the two towers, is found alive in the rubble, and eventually freed at approximately 11:00 p.m.

text: 8:30: U.S. President George W. Bush addresses the country from the White House in Washington, D.C.[47] Among his statements: "Today, our fellow citizens, our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts," "Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America. These acts shatter steel, but they cannot dent the steel of American resolve," and "The search is underway for those who are behind these evil acts...we will make no distinction between the terrorists who committed these acts and those who harbor them."

text: As Bush speaks, members of Congress tell CNN that during private briefings with senior administration officials, they were told that the administration had enough evidence that it was "confident" the attacks are the work of Osama bin Laden and his al-Qaeda terrorist network.

text: 9:00 p.m.[edit]

text: 9:00: President Bush meets his full National Security Council, followed roughly half an hour later by a meeting with a smaller group of key advisers. Bush and his advisers have evidence that Osama bin Laden is behind the attacks. CIA Director Tenet says that al-Qaeda and the Taliban in Afghanistan are essentially one and the same. Bush says, "Tell the Taliban we're finished with them."

text: 10:00 p.m.[edit]

text: 10:00: There are reports (later proven incorrect) of many survivors buried in rubble in New York making cell phone calls. Only two more survivors will be pulled from the rubble on September 12 and neither of them had made cell phone calls.

text: 11:00 p.m.[edit]

text: 11:00: After 13 hours, the NYPD, FDNY and PAPD finally dig out Will Jimeno. They learn that Port Authority police sergeant John McLoughlin is also trapped. The NYPD, FDNY and PAPD dig him out at 8:00 am the next morning after he has been there for almost a day.

text: 11:30: Before sleeping, President Bush enters into his journal: "The Pearl Harbor of the 21st century took place today...We think it's Osama bin Laden."[48]


document_title: Hassan (given name)

question_text: what is the meaning of hassan in english

root

text: Hassan (given name)

text: Etymology and spelling[edit]

text: The name Hassan in Arabic means 'handsome' or 'good', or 'benefactor'.

tag: p

text: There are two different Arabic names that are both romanized with the spelling "Hassan". However, they are pronounced differently, and in Arabic script spelled differently.

text:
The more common name حَسَن Ḥasan (as in the name of the Islamic prophet, Muhammad's grandson Hasan ibn Ali ), [3] coming from the triconsonantal root Ḥ-S-N, has two short vowels and a single /s/. Its meaning is 'the good' or 'the handsome'. Its usual form in Classical Arabic is الحسن al-Ḥasan, incorporating the definite article al-, which may be omitted in modern Arabic names.
The name حَسَّان Ḥassān, which comes from the same Arabic root, has a long vowel and a doubled /sː/. Its meaning is 'doer of good' or 'benefactor'. It is not used with the definite article in Classical Arabic.

tag: ul

text: In the romanized spelling Hassan, it is not possible to distinguish which of the two names is intended. The ambiguity can be removed by romanizing the former name as Hassan with a single a, and reserving the spelling with doubled a for the latter name, or romanizing the former as Hasan and the latter as Hassan.

text: King al-Ḥasan of Morocco (officially romanized as Hassan, with a double ss, due to the influence of French orthography) is an example of the former. The early Islamic poet Ḥassān ibn Thābit is an example of the latter. In the original Arabic, the two different names are easily distinguished.

text:
In Hebrew: חסן
In Arabic: حسن, حسان
In Turkish: Hasan
In Bosnian: Hasan
In Albanian: Hasan
In Azerbaijan: Həsən
In Kurdish: Hesan
In Kazakh: Asan or Äsem
In Somali: Xasan
In Sub-Saharan Africa: Lassana, Alassane and Lacen, derived from al-Hassan.
In French: Hassan, Hassen or Hacen
In Spanish: Hassan, Hassán, Hacen, Hacén, Jassan, Jassán, Jasan or Jasán
In Italian: Cassan, Cassano, Cassani, Gazzano, Gazzani, Gassano, Gassani.
In Macedonian: Hasan
In Croatian or Serbian: Asan or Hasan
In Bulgarian (in Cyrillic): Хасан
In Russian (in Cyrillic): Хасан, Хассан, Хассен, Хэссан, Гасан
In Finland: Hasanen, with the Finnish ending for surnames, -en.[4]
In Chinese: 哈桑/哈山 (Hā Sāng/Hā Shān)

text: People[edit]

text: Hacine[edit]

text: Hacine Cherifi, former French boxer

text: Hasan[edit]

text:
Abu l-Hasan Ali, Sultan of Granada, also known as Muley Hacén in Spanish
Hasan al-Askari, eleventh Imam of Twelver Shi‘ism
al-Ḥasan al-Baṣrī, prominent early Islamic scholar
Hasan ibn Ali, the fifth caliph of Islam, the first grandson of Muḥammad, and son of Alī ibn Abī Ṭālib, the fourth caliph of Islam
Hasan Čengić, Bosnian former Deputy Prime Minister and Defense Minister
Hasan Cetinkaya, Swedish footballer
Hasan Corso, an Italian who was part of the army of janissaries in the Turkish army
Hasan Doğan, Turkish 37th president of the TFF
Hasan Gemici, Turkish sports wrestler
Hasan Güngör, Turkish sports wrestler
Hasan Hamdan, Lebanese actor and voice actor
Hasan Izzet, Ottoman general
Hasan Kabze, Turkish footballer
Hasan Minhaj, American comedian
Hasan Muratović, former Bosniak rector of the University of Sarajevo and former prime minister
Hasan Bülent Paksoy, Turkish scientist
Hasan Polatkan (1915–1961), executed Turkish politician
Hasan Salihamidžić, a Bosnian football midfielder
Hasan Sönmez, Turkish footballer
Hasan Şaş, Turkish footballer
Hasan Ali Yücel, Turkish Minister of Education

text: Hasson[edit]

text: Hasson Arbubakrr, a former NFL and CFL player

text: Hassan[edit]

text:
Prince Hassan, Served as Crown Prince of Jordan under King Hussein's reign
Hassan II of Morocco, the father of the current King of Morocco
Hassan Adams, NBA player
Hassan (C&C), General Hassan in the Command and Conquer continuity
Muse Hassan Sheikh Sayid Abdulle, Somali politician and former army General
Hassan Assad, real name of professional wrestler Montel Vontavious Porter
Hasan al-Banna, founder of the Muslim Brotherhood
Hassan Abdillahi, Somali journalist and activist
Hassan Abshir Farah, former Prime Minister of Somalia
Hassan Heshmat (born 1920), Egyptian sculptor
Hassan Johnson, American actor
Hassan Jones, former professional American football player
Hassan Mohamed, Qatari basketball player
Hassan Mohammed Abdirahman, real name of Somali singer-songwriter Aar Maanta
Hassan Nader, retired Moroccan footballer
Hassan Nasrullah, leader of Hezbollah
Hassan Al-Qazwini, Islamic Center Imam
Hassan Roshdieh, Iranian teacher, politician, and journalist
Hassan Rowshan, Iraniamanagerial Hansen all coach, manager, and former player
Hassan Shamsid-Deen, American football player
Hassan Sheikh Mohamud, President of Somalia
Hassan Kamel al-Sabbah, a Lebanese electrical and electronics research engineer
Hassan Whiteside, American basketball player, NBA player
Salah-Hassan Hanifes, a Druze Israeli politician who served as a member of the Knesset

text: Hassane[edit]

text:
Hassane Alla (born 1980), Moroccan footballer
Hassane Azzoun (born 1979), Algerian judoka
Hassane Brahim (born 1989), Chadian footballer
Hassane Dicko, Burkina Faso politician
Hassane Hamadi, Comorian politician
Hassane Kamara (born 1994), Gambian footballer
Ibrahim Hassane Mayaki (born 1951), Niger politician and Prime Minister
Said Hassane Said Hachim (born 1932), Comorian politician

text: Hasaan[edit]

text: Hasaan Ibn Ali, American jazz pianist and composer, born William Henry Langford, Jr.

text: Hassanal[edit]

text: Hassanal Bolkiah (born 1946), the 29th Sultan and Yang Di-Pertuan of Brunei

text: Hassen[edit]

text:
Hassen Bejaoui, Tunisian soccer player
Hassen Gabsi, a Tunisian soccer player

text: Khasan[edit]

text:
Khasan Baroyev, Russian wrestler of Ossetian origin
Khasan Dzhunidov, Russian footballer
Khasan Isaev, Bulgarian freestyle wrestler
Khasan Israilov, Soviet Chechen journalist and poet
Khasan Mamtov, Russian footballer
Khasan Yandiyev, Russian judge

text: Khassan[edit]

text: Khassan Baiev, Chechen-American trauma surgeon

text: Fictional characters[edit]

text: Ĥassan, in the film A Girl Named Maĥmood


document_title: Spaceflight

question_text: when did the first rocket go into space

question_tokens: when did the first rocket go into space

text: Spaceflight

text: History[edit]

text: The first theoretical proposal of space travel using rockets was published by Scottish astronomer and mathematician William Leitch, in an 1861 essay "A Journey Through Space".[1] More well-known (though not widely outside Russia) is Konstantin Tsiolkovsky's work, "Исследование мировых пространств реактивными приборами" (The Exploration of Cosmic Space by Means of Reaction Devices), published in 1903.

text: Spaceflight became an engineering possibility with the work of Robert H. Goddard's publication in 1919 of his paper A Method of Reaching Extreme Altitudes. His application of the de Laval nozzle to liquid fuel rockets improved efficiency enough for interplanetary travel to become possible. He also proved in the laboratory that rockets would work in the vacuum of space;[specify] nonetheless, his work was not taken seriously by the public. His attempt to secure an Army contract for a rocket-propelled weapon in the first World War was defeated by the November 11, 1918 armistice with Germany.

text: Nonetheless, Goddard's paper was highly influential on Hermann Oberth, who in turn influenced Wernher von Braun. Von Braun became the first to produce modern rockets as guided weapons, employed by Adolf Hitler. Von Braun's V-2 was the first rocket to reach space, at an altitude of 189 kilometers (102 nautical miles) on a June 1944 test flight.[2]

text: Tsiolkovsky's rocketry work was not fully appreciated in his lifetime, but he influenced Sergey Korolev, who became the Soviet Union's chief rocket designer under Joseph Stalin, to develop intercontinental ballistic missiles to carry nuclear weapons as a counter measure to United States bomber planes. Derivatives of Korolev's R-7 Semyorka missiles were used to launch the world's first artificial Earth satellite, Sputnik 1, on October 4, 1957, and later the first human to orbit the Earth, Yuri Gagarin in Vostok 1, on April 12, 1961.[3]

text: At the end of World War II, von Braun and most of his rocket team surrendered to the United States, and were expatriated to work on American missiles at what became the Army Ballistic Missile Agency. This work on missiles such as Juno I and Atlas enabled launch of the first US satellite Explorer 1 on February 1, 1958, and the first American in orbit, John Glenn in Friendship 7 on February 20, 1962. As director of the Marshall Space Flight Center, Von Braun oversaw development of a larger class of rocket called Saturn, which allowed the US to send the first two humans, Neil Armstrong and Buzz Aldrin, to the Moon and back on Apollo 11 in July 1969. Over the same period, the Soviet Union secretly tried but failed to develop the N1 rocket to give them the capability to land one person on the Moon.

text: Phases[edit]

text: Launch[edit]

text: Rockets are the only means currently capable of reaching orbit or beyond. Other non-rocket spacelaunch technologies have yet to be built, or remain short of orbital speeds. A rocket launch for a spaceflight usually starts from a spaceport (cosmodrome), which may be equipped with launch complexes and launch pads for vertical rocket launches, and runways for takeoff and landing of carrier airplanes and winged spacecraft. Spaceports are situated well away from human habitation for noise and safety reasons. ICBMs have various special launching facilities.

text: A launch is often restricted to certain launch windows. These windows depend upon the position of celestial bodies and orbits relative to the launch site. The biggest influence is often the rotation of the Earth itself. Once launched, orbits are normally located within relatively constant flat planes at a fixed angle to the axis of the Earth, and the Earth rotates within this orbit.

text: A launch pad is a fixed structure designed to dispatch airborne vehicles. It generally consists of a launch tower and flame trench. It is surrounded by equipment used to erect, fuel, and maintain launch vehicles.

text: Reaching space[edit]

text: The most commonly used definition of outer space is everything beyond the Kármán line, which is 100 kilometers (62 mi) above the Earth's surface. The United States sometimes defines outer space as everything beyond 50 miles (80 km) in altitude.

text: Rockets are the only currently practical means of reaching space. Conventional airplane engines cannot reach space due to the lack of oxygen. Rocket engines expel propellant to provide forward thrust that generates enough delta-v (change in velocity) to reach orbit.

text: For manned launch systems launch escape systems are frequently fitted to allow astronauts to escape in the case of emergency.

text: Alternatives[edit]

text: Many ways to reach space other than rockets have been proposed. Ideas such as the space elevator, and momentum exchange tethers like rotovators or skyhooks require new materials much stronger than any currently known. Electromagnetic launchers such as launch loops might be feasible with current technology. Other ideas include rocket assisted aircraft/spaceplanes such as Reaction Engines Skylon (currently in early stage development), scramjet powered spaceplanes, and RBCC powered spaceplanes. Gun launch has been proposed for cargo.

text: Leaving orbit[edit]

text: Achieving a closed orbit is not essential to lunar and interplanetary voyages. Early Russian space vehicles successfully achieved very high altitudes without going into orbit. NASA considered launching Apollo missions directly into lunar trajectories but adopted the strategy of first entering a temporary parking orbit and then performing a separate burn several orbits later onto a lunar trajectory. This costs additional propellant because the parking orbit perigee must be high enough to prevent reentry while direct injection can have an arbitrarily low perigee because it will never be reached.

text: However, the parking orbit approach greatly simplified Apollo mission planning in several important ways. It substantially widened the allowable launch windows, increasing the chance of a successful launch despite minor technical problems during the countdown. The parking orbit was a stable "mission plateau" that gave the crew and controllers several hours to thoroughly check out the spacecraft after the stresses of launch before committing it to a long lunar flight; the crew could quickly return to Earth, if necessary, or an alternate Earth-orbital mission could be conducted. The parking orbit also enabled translunar trajectories that avoided the densest parts of the Van Allen radiation belts.

text: Apollo missions minimized the performance penalty of the parking orbit by keeping its altitude as low as possible. For example, Apollo 15 used an unusually low parking orbit (even for Apollo) of 92.5 nmi by 91.5 nmi (171 km by 169 km) where there was significant atmospheric drag. But it was partially overcome by continuous venting of hydrogen from the third stage of the Saturn V, and was in any event tolerable for the short stay.

text: Robotic missions do not require an abort capability or radiation minimization, and because modern launchers routinely meet "instantaneous" launch windows, space probes to the Moon and other planets generally use direct injection to maximize performance. Although some might coast briefly during the launch sequence, they do not complete one or more full parking orbits before the burn that injects them onto an Earth escape trajectory.

text: Note that the escape velocity from a celestial body decreases with altitude above that body. However, it is more fuel-efficient for a craft to burn its fuel as close to the ground as possible; see Oberth effect and reference.[5] This is another way to explain the performance penalty associated with establishing the safe perigee of a parking orbit.

text: Plans for future crewed interplanetary spaceflight missions often include final vehicle assembly in Earth orbit, such as NASA's Project Orion and Russia's Kliper/Parom tandem.

text: Astrodynamics[edit]

text: Astrodynamics is the study of spacecraft trajectories, particularly as they relate to gravitational and propulsion effects. Astrodynamics allows for a spacecraft to arrive at its destination at the correct time without excessive propellant use. An orbital maneuvering system may be needed to maintain or change orbits.

text: Non-rocket orbital propulsion methods include solar sails, magnetic sails, plasma-bubble magnetic systems, and using gravitational slingshot effects.

text: Transfer energy[edit]

text: The term "transfer energy" means the total amount of energy imparted by a rocket stage to its payload. This can be the energy imparted by a first stage of a launch vehicle to an upper stage plus payload, or by an upper stage or spacecraft kick motor to a spacecraft.[6][7]

text: Reentry[edit]

text: Vehicles in orbit have large amounts of kinetic energy. This energy must be discarded if the vehicle is to land safely without vaporizing in the atmosphere. Typically this process requires special methods to protect against aerodynamic heating. The theory behind reentry was developed by Harry Julian Allen. Based on this theory, reentry vehicles present blunt shapes to the atmosphere for reentry. Blunt shapes mean that less than 1% of the kinetic energy ends up as heat that reaches the vehicle and the heat energy instead ends up in the atmosphere.

text: Landing[edit]

text: The Mercury, Gemini, and Apollo capsules all splashed down in the sea. These capsules were designed to land at relatively low speeds with the help of a parachute. Russian capsules for Soyuz make use of a big parachute and braking rockets to touch down on land. The Space Shuttle glided to a touchdown like a plane.

text: Recovery[edit]

text: After a successful landing the spacecraft, its occupants and cargo can be recovered. In some cases, recovery has occurred before landing: while a spacecraft is still descending on its parachute, it can be snagged by a specially designed aircraft. This mid-air retrieval technique was used to recover the film canisters from the Corona spy satellites.

text: Types[edit]

text: Unmanned[edit]

text: Unmanned spaceflight is all spaceflight activity without a necessary human presence in space. This includes all space probes, satellites and robotic spacecraft and missions. Unmanned spaceflight is the opposite of manned spaceflight, which is usually called human spaceflight. Subcategories of unmanned spaceflight are “robotic spacecraft” (objects) and “robotic space missions” (activities). A robotic spacecraft is an unmanned spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe.

text: Unmanned space missions use remote-controlled spacecraft. The first unmanned space mission was Sputnik I, launched October 4, 1957 to orbit the Earth. Space missions where animals but no humans are on-board are considered unmanned missions.

text: Benefits[edit]

text: Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn, Uranus, and Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are the only way to explore them. Telerobotics also allows exploration of regions that are vulnerable to contamination by Earth micro-organisms since spacecraft can be sterilized. Humans can not be sterilized in the same way as a spaceship, as they coexist with numerous micro-organisms, and these micro-organisms are also hard to contain within a spaceship or spacesuit.

text: Telepresence[edit]

text: Telerobotics becomes telepresence when the time delay is short enough to permit control of the spacecraft in close to real time by humans. Even the two seconds light speed delay for the Moon is too far away for telepresence exploration from Earth. The L1 and L2 positions permit 400-millisecond round trip delays, which is just close enough for telepresence operation. Telepresence has also been suggested as a way to repair satellites in Earth orbit from Earth. The Exploration Telerobotics Symposium in 2012 explored this and other topics.[8]

text: Human[edit]

text: The first human spaceflight was Vostok 1 on April 12, 1961, on which cosmonaut Yuri Gagarin of the USSR made one orbit around the Earth. In official Soviet documents, there is no mention of the fact that Gagarin parachuted the final seven miles.[9] Currently, the only spacecraft regularly used for human spaceflight are the Russian Soyuz spacecraft and the Chinese Shenzhou spacecraft. The U.S. Space Shuttle fleet operated from April 1981 until July 2011. SpaceShipOne has conducted two human suborbital spaceflights.

text: Sub-orbital[edit]

text: On a sub-orbital spaceflight the spacecraft reaches space and then returns to the atmosphere after following a (primarily) ballistic trajectory. This is usually because of insufficient specific orbital energy, in which case a suborbital flight will last only a few minutes, but it is also possible for an object with enough energy for an orbit to have a trajectory that intersects the Earth's atmosphere, sometimes after many hours. Pioneer 1 was NASA's first space probe intended to reach the Moon. A partial failure caused it to instead follow a suborbital trajectory to an altitude of 113,854 kilometers (70,746 mi) before reentering the Earth's atmosphere 43 hours after launch.

text: The most generally recognized boundary of space is the Kármán line 100 km above sea level. (NASA alternatively defines an astronaut as someone who has flown more than 50 miles (80 km) above sea level.) It is not generally recognized by the public that the increase in potential energy required to pass the Kármán line is only about 3% of the orbital energy (potential plus kinetic energy) required by the lowest possible Earth orbit (a circular orbit just above the Kármán line.) In other words, it is far easier to reach space than to stay there. On May 17, 2004, Civilian Space eXploration Team launched the GoFast Rocket on a suborbital flight, the first amateur spaceflight. On June 21, 2004, SpaceShipOne was used for the first privately funded human spaceflight.

text: Point-to-point[edit]

text: Point-to-point sub-orbital spaceflight is a category of spaceflight in which a spacecraft uses a sub-orbital flight for transportation. This can provide a two-hour trip from London to Sydney, which would be much faster than what is currently over a twenty-hour flight. Today, no company offers this type of spaceflight for transportation. However, Virgin Galactic has plans for a spaceplane called SpaceShipThree, which could offer this service in the future.[10] Suborbital spaceflight over an intercontinental distance requires a vehicle velocity that is only a little lower than the velocity required to reach low Earth orbit.[11] If rockets are used, the size of the rocket relative to the payload is similar to an Intercontinental Ballistic Missile (ICBM). Any intercontinental spaceflight has to surmount problems of heating during atmosphere re-entry that are nearly as large as those faced by orbital spaceflight.

text: Orbital[edit]

text: A minimal orbital spaceflight requires much higher velocities than a minimal sub-orbital flight, and so it is technologically much more challenging to achieve. To achieve orbital spaceflight, the tangential velocity around the Earth is as important as altitude. In order to perform a stable and lasting flight in space, the spacecraft must reach the minimal orbital speed required for a closed orbit.

text: Interplanetary[edit]

text: Interplanetary travel is travel between planets within a single planetary system. In practice, the use of the term is confined to travel between the planets of our Solar System.

text: Interstellar[edit]

text: Five spacecraft are currently leaving the Solar System on escape trajectories, Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons. The one farthest from the Sun is Voyager 1, which is more than 100 AU distant and is moving at 3.6 AU per year.[12] In comparison, Proxima Centauri, the closest star other than the Sun, is 267,000 AU distant. It will take Voyager 1 over 74,000 years to reach this distance. Vehicle designs using other techniques, such as nuclear pulse propulsion are likely to be able to reach the nearest star significantly faster. Another possibility that could allow for human interstellar spaceflight is to make use of time dilation, as this would make it possible for passengers in a fast-moving vehicle to travel further into the future while aging very little, in that their great speed slows down the rate of passage of on-board time. However, attaining such high speeds would still require the use of some new, advanced method of propulsion.

text: Intergalactic[edit]

text: Intergalactic travel involves spaceflight between galaxies, and is considered much more technologically demanding than even interstellar travel and, by current engineering terms, is considered science fiction.

text: Spacecraft[edit]

text: Spacecraft are vehicles capable of controlling their trajectory through space.

text: The first 'true spacecraft' is sometimes said to be Apollo Lunar Module,[13] since this was the only manned vehicle to have been designed for, and operated only in space; and is notable for its non aerodynamic shape.

text: Propulsion[edit]

text: Spacecraft today predominantly use rockets for propulsion, but other propulsion techniques such as ion drives are becoming more common, particularly for unmanned vehicles, and this can significantly reduce the vehicle's mass and increase its delta-v.

text: Launch systems[edit]

text: Launch systems are used to carry a payload from Earth's surface into outer space.

text: Expendable[edit]

text: Reusable[edit]

text:
The Space Shuttle Columbia seconds after engine ignition on mission STS-1

Columbia landing, concluding the STS-1 mission

Columbia launches again on STS-2

tag: table

text: Challenges[edit]

text: Space disasters[edit]

text: All launch vehicles contain a huge amount of energy that is needed for some part of it to reach orbit. There is therefore some risk that this energy can be released prematurely and suddenly, with significant effects. When a Delta II rocket exploded 13 seconds after launch on January 17, 1997, there were reports of store windows 10 miles (16 km) away being broken by the blast.[15]

text: Space is a fairly predictable environment, but there are still risks of accidental depressurization and the potential failure of equipment, some of which may be very newly developed.

text: In 2004 the International Association for the Advancement of Space Safety was established in the Netherlands to further international cooperation and scientific advancement in space systems safety.[16]

text: Weightlessness[edit]

text: In a microgravity environment such as that provided by a spacecraft in orbit around the Earth, humans experience a sense of "weightlessness." Short-term exposure to microgravity causes space adaptation syndrome, a self-limiting nausea caused by derangement of the vestibular system. Long-term exposure causes multiple health issues. The most significant is bone loss, some of which is permanent, but microgravity also leads to significant deconditioning of muscular and cardiovascular tissues.

text: Radiation[edit]

text: Once above the atmosphere, radiation due to the Van Allen belts, solar radiation and cosmic radiation issues occur and increase. Further away from the Earth, solar flares can give a fatal radiation dose in minutes, and the health threat from cosmic radiation significantly increases the chances of cancer over a decade exposure or more.[17]

text: Life support[edit]

text: In human spaceflight, the life support system is a group of devices that allow a human being to survive in outer space. NASA often uses the phrase Environmental Control and Life Support System or the acronym ECLSS when describing these systems for its human spaceflight missions.[18] The life support system may supply: air, water and food. It must also maintain the correct body temperature, an acceptable pressure on the body and deal with the body's waste products. Shielding against harmful external influences such as radiation and micro-meteorites may also be necessary. Components of the life support system are life-critical, and are designed and constructed using safety engineering techniques.

text: Space weather[edit]

text: Space weather is the concept of changing environmental conditions in outer space. It is distinct from the concept of weather within a planetary atmosphere, and deals with phenomena involving ambient plasma, magnetic fields, radiation and other matter in space (generally close to Earth but also in interplanetary, and occasionally interstellar medium). "Space weather describes the conditions in space that affect Earth and its technological systems. Our space weather is a consequence of the behavior of the Sun, the nature of Earth's magnetic field, and our location in the Solar System."[19]

text: Space weather exerts a profound influence in several areas related to space exploration and development. Changing geomagnetic conditions can induce changes in atmospheric density causing the rapid degradation of spacecraft altitude in Low Earth orbit. Geomagnetic storms due to increased solar activity can potentially blind sensors aboard spacecraft, or interfere with on-board electronics. An understanding of space environmental conditions is also important in designing shielding and life support systems for manned spacecraft.

text: Environmental considerations[edit]

text: Rockets as a class are not inherently grossly polluting. However, some rockets use toxic propellants, and most vehicles use propellants that are not carbon neutral. Many solid rockets have chlorine in the form of perchlorate or other chemicals, and this can cause temporary local holes in the ozone layer. Re-entering spacecraft generate nitrates which also can temporarily impact the ozone layer. Most rockets are made of metals that can have an environmental impact during their construction.

text: In addition to the atmospheric effects there are effects on the near-Earth space environment. There is the possibility that orbit could become inaccessible for generations due to exponentially increasing space debris caused by spalling of satellites and vehicles (Kessler syndrome). Many launched vehicles today are therefore designed to be re-entered after use.

text: Applications[edit]

text: Current and proposed applications for spaceflight include:

text:
Earth observation satellites such as Spy satellites, weather satellites
Space exploration
Communication satellites
Satellite television
Satellite navigation
Space tourism
Protecting Earth from Potentially hazardous objects
Space colonization

text: Most early spaceflight development was paid for by governments. However, today major launch markets such as Communication satellites and Satellite television are purely commercial, though many of the launchers were originally funded by governments.

text: Private spaceflight is a rapidly developing area: space flight that is not only paid for by corporations or even private individuals, but often provided by private spaceflight companies. These companies often assert that much of the previous high cost of access to space was caused by governmental inefficiencies they can avoid. This assertion can be supported by much lower published launch costs for private space launch vehicles such as Falcon 9 developed with private financing. Lower launch costs and excellent safety will be required for the applications such as Space tourism and especially Space colonization to become successful.


document_title: List of past presumed highest mountains

question_text: tallest mountain in the world before mount everest

text: List of past presumed highest mountains

text: This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2013) (Learn how and when to remove this template message)

text: The examples and perspective in this article may not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (September 2017) (Learn how and when to remove this template message)

text: The following is a list of mountains that have been presumed, at one time, to be the highest mountain in the world. How general were the following presumptions is unclear. Before the age of exploration, no geographer could make any plausible assumption.

text:
Chimborazo, 6,267 metres (20,561 ft). Presumed highest from sixteenth century until the beginning of the 19th century. Not in the top 100 highest mountains when measured from sea level, however due to the earth's equatorial bulge this is the farthest point from the Earth's center.
Nanda Devi, 7,816 metres (25,643 ft). Presumed highest in the world before Kangchenjunga was sighted in an era when Nepal was still closed to the outside world. Now known to be the 23rd highest mountain in the world.
Dhaulagiri, 8,167 metres (26,795 ft). Presumed highest from 1808[1] until 1847.[2] Now known to be the 7th highest mountain in the world.
Kangchenjunga, 8,586 metres (28,169 ft). Presumed highest from 1847 until 1852. Now known to be the 3rd highest mountain in the world.[2]
Mount Everest, 8,848 metres (29,029 ft). Established as highest in 1852 and officially confirmed in 1856.[3]
K2, 8,611 metres (28,251 ft). Discovered in 1856 before Mt. Everest was officially confirmed, K2's elevation became something of an enigma until it was officially resolved at a later date.[2] News media reported in 1986 that satellite measurements by the University of Washington during an expedition to K2 by George Wallenstein had given a height between 29,064 feet (8,859 m) and 29,228 feet (8,909 m).[4] This erroneous figure was quickly retracted, and K2's status as second highest was reaffirmed.[4]