The galaxy cluster Abell 370, nearly 5 million light-years away, is one of the first such clusters where astronomers observed the phenomenon of gravitational lensing. (NASA / EPA)
Gas and dust are emitted from the Carina Nebula, 7,500 light-years away. (NASA / AFP/Getty Images)
This colorful assortment of stars is a small region inside the massive globular cluster Omega Centauri, which boasts nearly 10 million stars and is about 16,000 light-years away. (NASA / AFP/Getty Images)