Astronomers Discover New Active Asteroid's Tail that Gives it a Comet-Like Appearance

Astronomers have discovered a new active asteroid within our solar system. Called 62412, the asteroid is located in the main asteroid belt between Mars and Jupiter, and is the very first comet-like objects seen in the Hygiea family of asteroids.

Asteroids come in families, which are essentially populations of asteroids that share similar proper orbital elements. It's thought that the members of these families are fragments of past asteroid collisions.

While families have been around for quite some time, active asteroids are only a newly recognized phenomenon. In addition 624112 is only the 13^th known active asteroid in the main asteroid belt, and it's estimated that there are only about 100 of them total.

So what are active asteroids? They have stable orbits between Mars and Jupiter like other asteroids, but they sometimes have the appearance of comets when dust or gas is ejected from their surfaces to create a sporadic tail effect. In this case, the scientists spotted the tail on the new asteroid and found that the asteroid rotated fast. It's possible that this rotation shifts material around on its surface, which then is emitted to form the comet-like appearance.

"Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn't, but this is all changing as we realize not all of these objects show activity all of the time," said Scott Sheppard, one of the researchers, in a news release. "We're actually looking anew through our deep survey at a population of objects that other people cannot easily observe, because we're going much deeper."

For 15 years, researchers thought the asteroid 642112 was simply a typical asteroid. It's only by investigating a bit deeper that scientists realized it was active. Now, researchers are looking at what causes asteroids to become active and what the tails are made up of.

The findings were presented at the American Astronomical Society's Division of Planetary Sciences meeting.