How to weigh a killer asteroid at 22 kilometers per second

Estimating a mass for a potentially hazardous asteroid (PHA) is perhaps the single most important thing to understand about it, after its trajectory. Actually doing so isn't easy though, as the mass for objects in the tens to hundreds of kilometers in size are too small to have their mass calculated by traditional radio-frequency tracking techniques. A new paper from Justin Atchison of the Johns Hopkins University Applied Physics Laboratory and his co-authors proposes a method that could find the mass of asteroids even on the smaller end of that range, but will require precise coordination. The research is published on the arXiv preprint server.