A new amateur video of the 1986 Challenger disaster has surfaced, more than 25 years after the space shuttle broke up mid-flight, killing all seven crew onboard.

The footage, revealed on the New Scientist website, is believed to be only the second such video known to exist.

It was shot by Bob Karman of Hicksville, New York, whose daughter now works for the magazine. He and his family were on holiday in Florida at the time, and witnessed the tragedy from Orlando airport.

On Jan. 28, 1986, the space shuttle Challenger exploded 73 seconds after launching from the Kennedy Space Center at Cape Canaveral. It fell in pieces into the Atlantic Ocean.

In Karman's home movie, it isn't immediately clear to onlookers that anything has gone wrong. "There it goes... They must be up there," one man can be heard to say, while others wonder what they are seeing and remark, "Look at the little tails coming down there."

"After shooting the video, I had a sense that something went wrong but it wasn't until we were on the plane that the pilot confirmed the tragedy," Karman told New Scientist.

He said he only recently realized the rarity of what he had captured and made a digital copy of the old VHS tape.

Only one other amateur recording of the disaster has ever been made public before now, a four-minute recording discovered in a Florida basement in 2010. At the time, the Guardian described it as "the only amateur film in existence of the world's worst space disaster, recorded in an era before mobile phone cameras, when even home camcorders were rare."