Phobos' orbital path plows through occasional plumes of Martian debris, meaning the tiny moon has been gathering Martian castoffs for millions of years.
Author James Head, professor of geological sciences, said that the mission is scheduled to be flown early in the next decade, so the question is not academic.
He said that the this work shows that samples from Mars can indeed be found in the soil of Phobos, and how their concentration might change with depth, asserting that will be critical in the design of the drills other equipment.
The Russian mission will be the space agency's second attempt to return a sample from Phobos.
This new research grew out of preparation for the original mission, which would still be en route to Phobos had it not encountered problems. Scientists had long assumed Phobos likely contained Martian bits, but Russian mission planners wanted to know just how much might be there and where it might be found. They turned to Head and Ken Ramsley, a visiting researcher in Brown's planetary geosciences group.
To answer those questions, Ramsley and Head started with a model based on our own Moon to estimate how much of Phobos' regolith (loose rock and dust on the surface) would come from projectiles. They then used gravitational and orbital data to determine what proportion of that projectile material came from Mars.
According to those calculations, the regolith on Phobos should contain Martian material at a rate of about 250 parts per million. The Martian bits should be distributed fairly evenly across the surface, mostly in the upper layers of regolith, the researchers showed.
And while 250 parts per million doesn't sound like a lot, the possibility of returning even a little Martian material to Earth gets planetary scientists excited. It's a nice bonus for a mission primarily aimed at learning more about Phobos, a mysterious little rock in its own right.
The research has been published in the journal Space and Planetary Science.
--ANI (Posted on 12-11-2013)