Hubble revealed a universe of galaxies that existed beyond ours — but he couldn't have done it without a little help.

HD 20794 d completes its orbit just shy of two Earth years, placing it well within reach of conditions that might harbor life ...

The brighter the star is overall, the longer the period of luminosity. Since the cepheids in the Magellanic Clouds were all about the same distance from Earth, Leavitt concluded that the period ...

Sirius, the Dog Star, is difficult to ignore. Ostentatiously scintillating on the southern horizon right now, the “Searing ...

Located less than 20 light years away, HD 20794d could potentially be one of the most Earth-like planets found so far, despite its extreme climatic variability.