Few scientific terms express a sense of sheer enormity more than the word "galaxy." Galaxies are massively massive. They're filled with more stars than any single person could count. They're billions of times brighter than our own Sun! Galaxies are huge! Except for Segue 2.
The W.M. Keck Observatory switched on both its adaptive optics lasers last month, creating the amazing spectacle of two powerful lasers firing into space simultaneously.
The total number of stars in the Universe "is likely three times bigger than realized." Yale University astronomer Pieter van Dokkum says there are "possibly trillions of Earths orbiting these stars," dramatically increasing the possibility of finding alien civilizations.