第三个地方：第一段里面 asteroids collide归为两类，在if if的里面，所以不是rubble piles，那就是...
Well, discovered in 2004, the asteroid quickly rose to the top of tables that measure the risk of so-calledpotentially hazardous asteroids (PHAs), or asteroids with widths of 460 feet (140 meters) or more that come within 20 lunar distances of Earth. Both the size of Apophis and how clos...
The present research has the goal of searching for trajectories around the double asteroid 2002CE, a system of Near-Earth Asteroids (NEAs) of the Apollo type. For every trajectory of the spacecraft, the evolution of the distances between the spacecraft and the two bodies...
We called these orbits "quasi-stable orbits", in the sense that they do not collide with any of the primaries nor travel to large distances from them. From these orbits, it is possible to make better observations of the bodies in any scenario, and a more accurate estimation of their ...