According to NASA Administrator Bill Nelson, the asteroid Dimorphos was intentionally hit by the refrigerator-sized Double Asteroid Redirection Test (DART) impactor on September 26. This caused it to enter a smaller, quicker orbit around its larger sibling Didymos.
The 11 hours, 55 minute orbit was reduced by DART to 11 hours, 23 minutes, he claimed. Dimorphos’ orbital period was accelerated by 32 minutes as opposed to the 10 minutes NASA had anticipated.
Nelson stated, “We demonstrated to the world that NASA is serious about protecting this planet.
The asteroid pair loop together around the sun every 2.1 years and pose no threat to Earth, but they posed an ideal test of the “kinetic impact” method of planetary defence in case an actual approaching object is ever detected.
“There is no risk in this case because this was a deliberately chosen target to make sure that this [asteroid crashing on Earth] would not happen,” Yvette Cendes, an astronomer at Harvard University, told news reporters.
DART’s success as a proof-of-concept has made a reality of science fiction.
Astronomers rejoiced in stunning images of matter spreading out thousands of kilometres in the wake of the impact. The pictures were collected by Earth and space telescopes as well as a satellite that had travelled to the zone with DART.
“I grew up watching Armageddon and Deep Impact and all that, and it is amazing to see this stuff become a reality,” Cendes said.
Thanks to its temporary new tail, Dimorphos, which is 160 metres (530-foot) in diameter or roughly the size of a big Egyptian pyramid, has turned into a man-made comet.
But quantifying just how well the test worked required an analysis of light patterns from ground telescopes, which took a few weeks to become apparent.
The binary asteroid system, which was about 11m km (6.8m miles) from Earth at impact, is visible only as a single dot from the ground.
Ahead of the test, NASA scientists said the results of the experiment would reveal whether the asteroid is a solid rock, or more like a “rubbish pile” of boulders bound by mutual gravity.