Astrophysics is the field of science that combines astronomical observations with physical principles. It may be argued that the first true astrophysicist was Sir Isaac Newton, who explained the orbits of the planets, which had been known from...

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar...

Lyman Spitzer Jr., 82, a pioneer in astrophysics and plasma physics credited with conceiving the Hubble Space Telescope and launching research in fusion aimed at developing a cheap, inexhaustible fuel supply, died of heart disease March 31 at his home in Princeton, N.J. ...

A new supercomputer model of the universe - the most complex such simulation ever created - lends credence to the theory that the original recipe for the real cosmos probably included both cold and hot versions of the mysterious ingredient known as dark matter....

One of the world's most powerful telescopes will be trained on the skies on Friday, searching for planets similar to our own from a mountaintop on one of Spain's Canary Islands.Perched 2,400 meters up on the Roque de los Muchachos peak in the Atlantic island...

One of the world's most powerful telescopes began spying on the universe on Friday, using its 34-foot wide mirror to search for planets similar to our own from a mountaintop on one of Spain's Canary Islands.Perched atop a 7,800 foot peak on the Atlantic island...

A listing of Edwin Hubble's astrophysics discoveries plus other discoveries of the 20th century. Plus, a discussion of end-of-the-universe theories.