School students recover Martian companion using Faulkes Telescope

Two girls from Victoria College, Belfast, have recovered a unique asteroid that is one of a very rare class of companions to the planet Mars.  Christina Larkin and Catherine O'Prey remotely controlled the 2-metre Faulkes Telescope North on the island of Maui,Hawaii, during a week's work experience at the Armagh Observatory.

The project was supervised by Observatory astronomer David Asher (pictured with Christina and Catherine) and suggested by his colleague, Apostolos Christou, an expert with a long-standing interest in this unusual class of asteroid.  The telescope owners, Las Cumbres Observatory, have provided Dr Asher with periods of observing time on the telescope with the object of encouraging young people to study science,technology, engineering and mathematics, and to help secondary school pupils observe asteroids.


The recovery of this object, first discovered in 2007 and not observed since, is very significant.  The asteroid is only the second known object in a so-called "Martian horseshoe"orbit, going around the Sun on nearly the same orbit as Mars.  Unlike the planet's two known moons, Phobos and Deimos, which orbit Mars much like an artificial satellite orbits the Earth, the unusual asteroid moves in a more complicated "horseshoe" pattern along the orbit of Mars, with the open end of the horseshoe centred near Mars itself.  The possibility of discovering asteroids in such orbits has fascinated theoreticians for years.   The only other known asteroid on a Martian horseshoe orbit moves on a highly unstable trajectory.

The asteroid, designated 2007 UR2, is a small body just a few hundred metres across (about the size of a small hill), and was discovered a little more than two years ago by the United States Near-Earth asteroid survey LINEAR. Dr Asher said "This asteroid was tracked for just over a month in 2007 but had not been observed since. There was a risk that it would have been lost had it not been recovered soon. With the new Faulkes observations its orbit is secure".

Faulkes Telescope North, like its southern twin in Australia, has a two-metre diameter mirror and was ideally suited to search for this celestial body.  "We needed to keep repointing the telescope slightly in order to search along the part of the sky where the asteroid might possibly have been. We found it in the last bit of sky we observed. Five minutes less and we'd have missed it!"said Catherine.

"It was a fantastic experience using the Faulkes telescope, and even better that we managed to plan our observations correctly in order to recover an asteroid which hadn't been observed in two years. I really enjoyed this wonderful opportunity", added Christina.