Binary Asteroid System 2006 VW139/288P

This set of Hubble Space Telescope photos reveals two asteroids orbiting each other that have comet-like features. These include a bright halo of material, called a coma, and a long tail of dust. The asteroid pair, called 2006 VW139/288P, was observed in September 2016 just before the asteroid made its closest approach to the Sun. The photos revealed ongoing activity in the binary system. The apparent movement of the tail is a projection effect due to the relative alignment between the Sun, Earth, and 2006 VW139/288P changing between observations. The tail orientation is also affected by a change in the particle size. Initially, the tail was pointing towards the direction where comparatively large (about 1 millimeter in size) dust particles were emitted in late July. However, from Sept. 20 on, the tail began to point in the opposite direction from the Sun, where small (about 10 microns in size) particles are blown away from the nucleus by radiation pressure.