The Guardian Astronomers often speak of the cosmic zoo, reflecting the exotic variety of phenomena to be seen in the deep space. Pulsars, colliding galaxies and superluminous quasars are just a few of the bizarre images their telescopes pick up. But right here in the solar system, we still have a few surprises in store. Such as an asteroid shaped like a dog's bone.
Cartoonists tend to draw asteroids as rocky spheres pockmarked by craters.
They're halfway correct. Asteroids not only slam into the moon and planets producing craters, but they're also holed themselves by smaller projectiles. Smaller bodies are expected to be irregular in profile. Our vantage point is so far from the main belt between Mars and Jupiter that only the largest asteroids can be resolved. While on its trip to Jupiter Nasa's Galileo spacecraft returned close-up photos of Gaspra and Ida, showing these to be angular and elongated, like pebbles.