The Sept. 11, 2001 terrorist attack is by far the most memorable moment shared by television viewers during the past 50 years, a study released on Wednesday concluded. The only thing that came close was President John F. Kennedy's assassination and its aftermath in 1963, but that was only for the people aged 55 and over who experienced those events as they happened instead of replayed as an historical artifact. Sony Electronics and the Nielsen television research company collaborated on the survey. They ranked TV moments for their impact not just by asking people if they remembered watching them, but if they recalled where they watched it, who they were with and whether they talked to other people about what they had seen. Following is a list of the top 20 events from the survey. Read a story on the survey here.

20 John F. Kennedy funeral (1963)

This Nov. 25, 1963 file photo shows three-year-old John F. Kennedy Jr. saluting his father's casket in Washington on Nov. 25, 1963, three days after the president was assassinated in Dallas. Widow Jacqueline Kennedy, center, and daughter Caroline Kennedy are accompanied by the late president's brothers Sen. Edward Kennedy, left, and Attorney General Robert Kennedy. (AP Photo, file)

19 Casey Anthony murder trial verdict (2011)

Casey Anthony, center, with her attorneys Jose Baez, left, and Dorothy Clay Sims, right, stand before the jury presents a verdict in her murder murder trial at the Orange County Courthouse Orlando, Fla., Tuesday, July 5, 2011. The jury acquitted Casey Anthony of murdering her daughter Caylee. (AP Photo/Red Huber, Pool)

18 Los Angeles riots, Rodney King beating (1992)

This May 1, 1992 file photo shows Rodney King making a statement at a Los Angeles news conference. King was the black motorist whose 1991 videotaped beating by Los Angeles police officers was the touchstone for one of the most destructive race riots in the nation's history. (AP Photo/David Longstreath, file)

17 Bush/Gore disputed election (2000)

Broward County canvassing board member Judge Robert Rosenberg uses a magnifying glass to examine a disputed ballot at the Broward County Courthouse in Fort Lauderdale, Fla., in this Nov. 24, 2000 file photo. A plan is in the works by states that would eliminate the Electoral College and ensure that the presidency always goes to the winner of the popular vote. The proposal is aimed at preventing a repeat of the 2000 election, when Al Gore got the most votes nationwide but George W. Bush put together enough victories in key states to win a majority in the Electoral College and capture the White House. (AP Photo/Alan Diaz, File)

16 Oklahoma City bombing (1995)

This April 19, 1995 file photo shows rescue workers standing in front of the Alfred P. Murrah Federal Building following an explosion in downtown Oklahoma City. (AP Photo/David Longstreath, File)

15 John F. Kennedy assassination (1963)

The limousine carrying mortally wounded President John F. Kennedy races toward the hospital seconds after he was shot in Dallas, Tx., Nov. 22, 1963. With secret service agent Clinton Hill riding on the back of the car, Mrs. John Connally, wife of the Texas governor, bends over her wounded husband, and Mrs. Kennedy leans over the president. (AP Photo/Justin Newman)

14 Wedding of Prince William and Kate Middleton (2011)

This April 29, 2011 file photo shows Prince William and Catherine, the Duchess of Cambridge, walking down the aisle at Westminster Abbey following their marriage in central London. (AP Photo/RICHARD POHLE, Pool)

13 Barack Obama Election Night speech (2008)

This Nov. 4, 2008 file photo shows President-elect Barack Obama, left, his wife Michelle Obama, right, and two daughters, Sasha, 7, and Malia, 10, second from right, as they wave at the election night rally in Chicago. (AP Photo/Jae C. Hong, File)

12 Capture and execution of Saddam Hussein (2006)

Captured former Iraqi leader Saddam Hussein undergoes medical examinations in Baghdad in this Dec. 14, 2003 file photo,in this image from television. (AP Photo/US Military via APTN)

11 Death of Whitney Houston (2012)

Filipino shoppers walk past the "tribute wall" for the late American singer Whitney Houston at the SM North EDSA shopping mall at suburban Quezon city northeast of Manila, Philippines Friday Feb. 17, 2012. The tribute wall was put up for fans to write their messages following Houston's sudden death Saturday at age 48. (AP Photo/Bullit Marquez)

10 Princess Diana's funeral (1997)

This Sept. 6, 1997 file photo shows the casket containing the body of Diana, Princess of Wales, as it is carried into Westminster Abbey by soldiers of the Welsh Guards, during funeral ceremonies in London. (AP Photo/Peter Dejong/POOL)

9 BP oil spill in Gulf of Mexico (2010)

In this April 21, 2010, file photo, the Deepwater Horizon oil rig burns in the Gulf of Mexico. (AP Photo/Gerald Herbert, File)

8 Columbine school shooting (1999)

This April 28, 1999 file photo shows an unidentified woman with 15 crosses posted on a hill above Columbine High School in Littleton, Colo. Wednesday, April 28, 1999 in remembrance of the 15 people who died during a school shooting on April 20. (AP Photo/Eric Gay, file)

7 The Japanese earthquake and tsunami (2011)

This March 12, 2011 file photo shows smokes rising from burning homes in Yamadamachi in Iwate Prefecture, northern Japan a day after a strong earthquake triggered a devastating tsunami in the area. (AP Photo/Kenji Shimizu, The Yomiuri Shimbun)

6 The O.J. Simpson White Bronco chase (1994)

A white Ford Bronco, driven by Al Cowlings and carrying O.J. Simpson, is trailed by police cars as it travels on a southern California freeway on June 17, 1994, in Los Angeles. Cowlings and Simpson led authorities on a chase after Simpson was charged with two counts of murder in the deaths of his ex-wife and her friend. (AP Photo/Joseph Villarin)

5 Death of Osama bin Laden (2011)

Crowds climb trees and celebrate in Lafayette Park early Monday, May 2, 2011, in front of the White House in Washington after President Barack Obama announced that Osama bin Laden had been killed. (AP Photo/Charles Dharapak)

4 The Challenger space shuttle explodes (1986)

In this Jan. 28, 1986 file photo, the space shuttle Challenger explodes shortly after lifting off from the Kennedy Space Center in Cape Canaveral, Fla. (AP Photo/Bruce Weaver, File)

3 The O.J. Simpson verdict (1995)

This Oct. 3, 1995 file photo shows O.J. Simpson, center, with defense attorneys F. Lee Bailey, left, and Johnnie Cochran after Simpson was found not guilty of murdering his ex-wife Nicole Brown Simpson and her friend Ron Goldman at the Criminal Courts Building in Los Angeles. (AP Photo/Myung J. Chun, file)

2 Hurricane Katrina (2005)

New Orleans residents wait to be rescued from the floodwaters of Hurricane Katrina Wednesday, Aug. 31, 2005 in New Orleans.

1 Sept. 11 terrorist attacks (2001)

In this Sept. 11, 2001, file photo, the twin towers of the World Trade Center burn behind the Empire State Building in New York. The Sept. 11, 2001 terrorist attack is by far the most memorable moment shared by television viewers during the past 50 years, a study released on Wednesday, July 11, 2012, concluded. (AP Photo/Marty Lederhandler, File)