Harvard University astronomers and Smithsonian Institution astronomers explore the cosmos together. The combination of the Harvard College Observatory (HCO) and the Smithsonian Astrophysical Observatory (SAO) is known as the Harvard-Smithsonian Center for Astrophysics (CfA).

News Releases

October 17, 2018

The single most important puzzle in today's cosmology (the study of the universe as a whole) can be summarized in one question: How old is it? For nearly a century -- since the discoveries by Einstein, Hubble, LeMaitre and others led to the big bang model of creation -- we have known the answer.

September 25, 2018

NASA has awarded a contract extension to the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts, to continue operations and science support for the agency's Chandra X-ray Observatory.

Latest Science Update

October 19, 2018

One year ago this week astronomers discovered an unusual object moving through space not too far from the Earth's orbit. In just a few days they realized it could not be a normal asteroid or comet – its path showed that it was not gravitationally bound to the solar system.

SI Specific Information

SI-specific information regarding the government shutdown may be found at alerts.si.edu. SAO staff are encouraged to review the website for updated information