Closing summary
We’re closing our live blog of Nasa’s Dart “planetary defense test” now after what scientists have hailed a “game-changing” achievement in crashing a spacecraft into a faraway asteroid.
Nasa chief Bill Nelson said the mission would “teach us how one day to protect our own planet from an incoming asteroid. We are showing that planetary defense is a global endeavor and it is very possible to save our planet.”
Mission managers at Johns Hopkins University’s applied physics laboratory say it could be up to two months before telescope observations will show whether the impact had sufficient force to alter the trajectory of the asteroid Dimorphos, 6.8m miles from Earth.
But the first part of the mission was successful, Dart’s crash landing 17 meters from its intended target on the asteroid the width of a football stadium close enough to count as “basically a bullseye”, according to deputy program manager Elena Adams.
Ralph Semmel, director of the Johns Hopkins applied physics laboratory, hailed the “game-changing” nature of the mission, adding that his team knew they had been successful when the video blacked out. “Normally, losing signal from a spacecraft is a very bad thing. But in this case, it was the ideal outcome,” he said.
Thanks for joining us. You can read our news story about the Dart mission here:
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Dart scientists: 'ideal outcome' for first planetary defense test
Scientists say it will be about two months before they know if the Dart spacecraft has altered the trajectory of the asteroid Dimorphos, but hailed the “ideal outcome” of the first stage of the planetary defense test.
Dart scored “basically a bullseye” on the asteroid about 6.8m miles from Earth when it crashed head-on at 7.14pm EDT, Dart deputy program manager Elena Adams said at a post-mission press conference:
We knew we were going to hit. All of us were holding our breath. I’m kind of surprised none of us passed out.
She said the craft had landed 17 meters from its target, which she said mission managers knew because “the asteroid was not completely lit from all the sides”. It was, she said, close enough to represent a complete success:
It was basically a bullseye. I think, as far as we can tell, the first planetary defense test was a success, and we can clap to that.
Whether the impact had enough force to move the asteroid from its trajectory remains to be seen. If it has, the second goal of the mission, to show humanity’s capability of diverting an Earth-bound large asteroid, will also have been achieved.
But scientists will spend at least two months monitoring the asteroid’s speed and movements, and making calculations.
Even so, Adams said:
Earthlings should sleep better, and I definitely will.
Other managers expressed their “absolute joy” at the successful collision.
Ralph Semmel, director of the Johns Hopkins applied physics laboratory, hailed the “game-changing” nature of what had just been achieved, adding that his team knew they had been successful when the video blacked out:
Normally, losing signal from a spacecraft is a very bad thing. But in this case, it was the ideal outcome.
Dart has now joined a long list of [Johns Hopkins’] applied physics laboratory’s firsts in space. The first photos of Earth from space, creation of satellite navigation with the transit system, the incredible New Horizons flyby of Pluto, and the record setting Parker Solar Probe that has touched the sun ...
We can now add to this this our world’s first planetary defense test mission. Congratulations to the Dart team and to Nasa on this historic accomplishment and first demonstration of a game changing planetary defense capability.
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