Dark matter, for example, is invisible to us, yet we can observe its effects, such as the formation of galaxy clusters ... black holes to the Boomerang Nebula, let’s see why these are some ...

A magnitude 10.2 star lies a bit more than 2″ east of the nebula. A big neighbor This week’s second large-telescope target is barred spiral galaxy NGC 3109 in the constellation Hydra the Water ...