Astronomers Spot Asteroid in Suicidal Motion Producing Debris – Astronomy Now

Using ground-based telescopes, whole-sky surveys, and even the Hubble Space Telescope, astronomers have discovered a suicidal asteroid that is disintegrating through solar heating and infrared emissions that make it spin faster and faster. .

Known as 6478 Gault, the asteroid is four to nine kilometers in diameter and features two tails of comet-like debris, released into space. The asteroid is in a destructive tendril caused by a phenomenon called YORP couple. When the body is warmed by the sun, the infrared radiation escapes, taking away heat and impulse.

This small force forces the asteroid to spin until centrifugal force can eventually defeat gravity. As the body becomes more and more unstable, landslides can flush out debris and dust into space, creating one or more tails. Of the 800,000 known asteroids between Mars and Jupiter, the "disturbances" of YORP occur about once a year.

"This event of self-destruction is rare," said Olivier Hainaut of the Southern European Observatory. "Active and unstable asteroids such as Gault are only now being detected by new survey telescopes that scan the entire sky, which means that asteroids such as Gault do not behave well can no longer escape detection."

The Gault debris tail was observed for the first time on January 5, 2019 by the University of Hawaii / NASA ATLAS telescopes, the Earth Asteroid Warning System, and archival data was collected. showed that the tail had been observed earlier, in December 2018, and a second, shorter tail was seen by various telescopes shortly thereafter.

A detailed analysis suggested that the two residue events occurred around October 28 and December 30, 2018. Follow-up observations indicated a two-hour rotation period for Gault, just at the threshold required for the material to begin. to fall and slide surface.

"Gault is the best example of a" fast smoking "rotator gun at the limit of two hours," said Jan Kleyna of the University of Hawai'i. "It could have been on the verge of instability for 10 million years. Even a very small disturbance, such as a slight impact of a pebble, could have triggered the recent outbursts. "

The tails should be visible for a few months before their dust is completely dispersed.