A bizarre comet-like object, discovered by NASA’s Hubble Space Telescope three years ago, is actually a dying asteroid, an Indian-origin astronomer has said.
Hubble telescope observed the mysterious X-shaped debris pattern and trailing streamers of dust soaring through the asteroid belt in January 2010.
It was believed to be a comet, most notably because of its long, well-formed tail.
The trail of particles and dust following the asteroid stretch for more than a million kilometres, roughly three times the distance from the Earth to the Moon.
Now, scientists believe the odd, X-shaped debris field, may be evidence that the object, known as Asteroid P/2010 A2, collided head-on with another asteroid in the recent past.
Another theory is that A2 is breaking itself apart due to an unsustainable spin, Discovery News reported.
“It’s hard to pin it down. This one certainly looks like it’s a collision but there are many mechanisms that may explain it,” said astronomer Jayadev Rajagopal, with the National Optical Astronomy Observatory.
“We are watching the death of an asteroid. This is the only one which is showing the event as it is happening,” Rajagopal told the American Astronomical Society conference in Indianapolis this week.
“We usually associate tails and coma and mass loss with comets. We think of them as dirty iceballs with mass kind of shedding off them. But there are a few asteroids which are starting to show us that asteroids have this activity too,” he said.
Follow-up observations are under way to measure how much material is in A2’s tail, which presently is shaped like a tube. Eventually, the tail will widen and more closely resemble the dusty trails of comets that trigger meteor showers on Earth when the planet passes through the stream.
P/2010 A2 was discovered by the Lincoln Near-Earth Asteroid Research project, a collaboration of the US Air Force, NASA and the Massachusetts Institute of Technology.
Later, astronomer David Jewitt, with the University of California at Los Angeles, used Hubble to get a closer look at the object and determined that its tail wasn’t smooth like a comet’s.
A2 has now completed one orbit around the Sun. How long it lasts will depend on the size of its particles and how fast they are moving.
“I expect it to hang around for quite a while,” Rajagopal said.