Smithsonian Astrophysical Observatory

Science Updates


The K2 Mission, an extension of the immensely successful NASA Kepler mission to search for exoplanets, has itself discovered nearly one hundred new exoplanets so far. K2 monitors stars for variability, the sign of a transiting exoplanet, but in the course of searching it makes many other variable star discoveries.


Helium is the second most abundant element in the universe, after hydrogen, and is a major constituent of the gas-giant planets in our Solar System. By contrast, helium is rare in the Earth's atmosphere, comprising less than about a thousandth of a percent of air.

The Smithsonian Astrophysical Observatory (SAO) is a "research institute" of the Smithsonian Institution. It is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). Because these research activities share Harvard and Smithsonian staff and resources, the links at this website will take you to information posted on the "CfA" pages.