Astronomers have spotted what’s been confirmed as a collision between two asteroids that took place just last year beyond the orbit of Mars.
After the debris was spotted, a team from the Max Planck Institute for Solar System Research (MPS) in Germany examined data from the OSIRIS camera onboard the European Space Agency’s Rosetta probe.
From these images, the team was able to study the debris trail in sufficient detail to confirm that this was indeed an inter-asteroid collision – and to actually date the initial impact time to within a five day period in February 2009.
“It has long been suspected that such collisions are taking place within the asteroid belt, but never before have the remains been observed so soon after the impact event and dated with such precision,” says Dr Stephen Lowry of the University of Kent.
“Asteroid astronomers can now, for the first time, study the physics of an impact debris trail as well as establishing how collisions of this nature supply the solar systems inventory of dust particles. These dust particles contribute to the well known phenomenon that is visible from Earth known as the Zodiacal Light.”
While the asteroid belt contains several million large and small fragments of rock, most collisions go unobserved. Until now, most of what scientists know about collisions between asteroids has been deduced from the presence of diffuse bands of dust spreading across the whole sky and representing events from the remote past.
“In comparison, it was practically yesterday that the asteroid named P/2010 A2 bumped into a small rock with a diameter of only a few meters,” says lead author Dr Colin Snodgrass of MPS. He compares the discovery to “finding a fresh dinosaur body instead of having to figure out how they looked from fossils”.