Photograph by National Geographic via AP

Pushing the Twitter Envelope

  1. The Deepest Spot on Earth

    The Deepest Spot on Earth

    Hollywood titan James Cameron is the latest Twitter user to take the ubiquitous online message service to a new frontier. In his case, it was nearly seven miles below the ocean surface on March 25, when he descended to the Mariana Trench in a one-person dive craft. Before Cameron, however, others were taking Twitter to extreme locales, from outer space to breaking news to politics. Here's a brief history of some of the more interesting places whence tweets have issued.

    Movie mogul James Cameron, the director of Avatar and Titanic, reached the deepest spot on earth, Challenger Deep, located in the Mariana Trench about 300 miles southwest of Guam. From his one-person submersible at a depth of 35,800 feet on March 25, Cameron sent this tweet: "Just arrived at the ocean's deepest pt. Hitting bottom never felt so good. Can't wait to share what I'm seeing w/ you." Cameron's dive was only the second manned mission to Challenger Deep since a 1960 U.S. Navy effort. Cameron's interest in ocean depths stretches to at least 1989, when he wrote and directed The Abyss, a sci-fi suspense film about the hunt for a sunken nuclear submarine.

    Photograph by National Geographic via AP
  2. Live from Abbottabad

    Live from Abbottabad

    As U.S. forces stormed a house in Abbottabad, Pakistan, one Sunday afternoon, a local resident, Sohaib Athar, mused on Twitter about the annoying helicopters buzzing around his neighborhood. Hours later, Athar, an IT consultant, learned with the rest of the world that he had unintentionally been live-tweeting the May 2, 2011, Navy SEAL raid that killed Osama bin Laden. The event turned Athar into a media sensation and a legend among the Twitterati. Athar is just back home from Austin, Texas, where he discussed his experience at the 2012 South by Southwest conference—and he's still tweeting to more than 73,000 followers: "I can't believe southwest airline lost my new bag from Austin to Tampa!"

    Photograph by Aamir Qureshi/AFP/Getty Images
  3. The 'Miracle on the Hudson'

    The 'Miracle on the Hudson'

    On Jan. 15, 2009, US Airways flight 1549 to Charlotte struck a skein of geese as it departed from New York's LaGuardia Airport and lost power from both engines. Minutes later, unable to reach an airport, Captain Chesley Sullenberger piloted the Airbus A320 to a landing on the Hudson River, where ferry and police boats raced to collect passengers from the jet's wings. No one was killed or severely injured in the crash. Janis Krums was on the Staten Island Ferry that afternoon and tweeted what is believed to be the first photo from the accident. Krums, an investor and entrepreneur, devotes a section of his blog to the "Miracle on the Hudson" media coverage he garnered and is helping to promote a new citizen-journalism venture called

    Photograph by Janis Krums/TwitPic
  4. Hello From Hubble

    Hello From Hubble

    In May 2009, NASA launched STS-125, the final service mission for the Hubble Space Telescope. On May 12, the day after launch, astronaut Michael Massimino, tweeting as @Astro_Mike, sent the first Twitter missive from space: "From orbit: Launch was awesome!! I am feeling great, working hard, & enjoying the magnificent views, the adventure of a lifetime has begun!" Massimino's Astro_Mike handle has nearly 1.3 million followers—and he met the band Radiohead this month.

    Photograph by Stephen Alvarez/National Geographic
  5. Atop Mount Everest

    Atop Mount Everest

    Irish mountaineer Gavin Bate has climbed Mount Everest six times to raise money for charity but reached the summit only on his last climb in June 2011. Two years earlier, however, Bate was credited with becoming the first climber to tweet from the grueling expedition up Everest.

    Photograph by Alex Treadway/National Geographic
  6. An Abortion Shared

    An Abortion Shared

    In February 2010, Angie Jackson learned she was pregnant after her birth control had failed. Jackson decided to have an abortion by taking RU-486, the common name for the drug mifepristone, a steroid that induces abortion. She made a YouTube video about the decision and began tweeting about the abortion shortly after taking mifepristone. Needless to say, Jackson, who calls herself an "atheist, pro-choice vlogger and autism mommy" on her Twitter feed, created headlines around the world.

  7. A Murder Trial Broadcast

    A Murder Trial Broadcast

    In December 2011, the Arkansas Supreme Court overturned the murder conviction of Erickson Dimas-Martinez, who had been sentenced to die for killing a teenager in 2006. The reason? A member of the jury for Dimas-Martinez's trial had been tweeting during the proceedings. "Choices to be made. Hearts to be broken … We each define the great line," juror Randy Franco tweeted during the trial. Before the guilty verdict was read, Franco wrote: "It's over."

  8. Crossing Antarctica

    Crossing Antarctica

    British writer and explorer Felicity Aston set off November 25, 2011, to become the first woman to ski solo across Antarctica. On Jan. 22, 2012, after 1,055 miles, Aston completed the journey at Hercules Inlet. She also tweeted liberally during the trek. Aston raised $3400 to help fund a memorial in the Falkland Islands dedicated to explorers who had died on Antarctica pursuing science. Among her messages: "Happy Christmas from Antarctica! I think I win the contest for 'whitest christmas' hands down!"