Sometimes big things come in small packages, or so the saying goes. Such is the case with Segue 2, the name of a tiny galaxy near our own that is being called the "most lightweight" ever discovered.

Observations of the ultra-faint galaxy Segue 2, using the W. M. Keck Observatory, determined its mass to be significantly lower than previously estimated, at approximately 1000 stars. Segue 2's low ...