The Mice [NGC 4676] are two gallaxies about 300 million light-years from Earth. These two galaxies will eventually merge into a single, giant galaxy. Credit: NASA, H. Ford [JHU], G. Illingworth [UCSC/LO], M.Clampin [STScI], G. Hartig [STScI], the ACS Science Team, and ESA.
Why does a returning boomerang come back?
When most of us think of boomerangs, we imagine somebody throwing a curved stick that eventually turns around and comes right back to the thrower's hand. This device is simply amazing, and a wonderful application of some laws of physics relating to aerodynamic lift and angular momentum.