One asteroid just wants to be a comet. Dubbed asteroid 62412, it even sports a tail like you would see on a comet.
Comets and asteroids used to be easy to tell apart. Comets are generally made of rock and ice. As the ice portion becomes heated by the sun, vapor blasts off the comet creating a coma around the nucleus and a long tail.
Asteroids are mostly made of rock, and don’t have tails. Or, at least, that was researchers’ understanding a few years ago. Today, there have been more than a dozen asteroids found with dusty tails just hanging out in the solar system’s Main Belt – the asteroid belt between Mars and Jupiter.
Asteroid 62412 is the latest to be discovered that has grown a tail. Until recently, 62412 was a typical asteroid. It has now been reclassified as an active asteroid.
Now, these tails are faint for the most part. They aren’t the impressive tails you would think of with comets. Here’s an image below (courtesy of Scott Sheppard).
“Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn’t, but that is all changing as we realize that not all of these objects show activity all of the time,” Sheppard said.
What’s causing these asteroids to have tails? One theory suggests collisions are exposing icy parts of the asteroid to the sun. Which then turns to vapor just like a comet. But, asteroids don’t usually have the quantity of ice that comets do. Hence the fainter tails.
These new discoveries come as astronomers have better tools at their disposal. “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,” Sheppard said.