During the same month, team member Dr. Francois Menard, currently a visiting scientist at CFHT, obtained adaptive optics images. This week, Merline and his colleagues reported to an annual meeting of international scientists specializing in solar system studies on two years of asteroid surveys conducted at three observatories equipped with the new adaptive optics systems. It is possible that a few more moonlets might emerge from more sophisticated analysis of the data we have collected. Pulcova is an asteroid about 90 miles in diameter. Its small satellite, roughly a 10th its size, orbits Pulcova every four days at a distance of about 500 miles.
Asteroidal companions provide vital information about asteroids that has been difficult to obtain.
But an asteroidal satellite, or twin, is a body whose trajectory is so mightily deflected by the asteroid's gravity that it is actually forced to orbit around it. The revolution time provides a measure of the body's mass, hence density. Using such techniques, Merline's team find that Eugenia, Pulcova, and Antiope are all rather light bodies. They are much less dense than familiar rocks, more like ice, but their surfaces appear very dark, like rock. Interesting differences in the densities motivate further research on asteroids with satellites.