CAPE CANAVERAL, Fla. (AP) – The only spacecraft ever to orbit Mercury ended its four-year tour with a crash landing Thursday. NASA’s Messenger plunged from orbit as planned and slammed into the sun’s ...

An awkward-looking, spherical satellite the size of a grapefruit launched in March 1958, and was boosted into a high elliptical orbit. The satellite, named Vanguard-1, was a test of launch ...

Astronomers discovered that Mercury’s orbit makes it on average the closest planet to every other planet including distant Neptune. Bruce Willis' Wife Defends 'Difficult' Decision as His Condition ...

Earth with a highly elliptical orbit would experience extreme temperature swings; how would life adapt? Judge Orders White House to Restore AP’s Access Kurt Russell delights fans as he reunites with ...