Main-belt asteroid Egeria is sliding past several stationary background stars tonight, offering a chance to catch its celestial motion.

Today in the history of astronomy, the man who revolutionized astronomy passes away.

Slicing through the Montes Alpes mountain range, Vallis Alpes is a favorite feature to view on the First Quarter Moon.

Today in the history of astronomy, space weather forecasters narrowly avert nuclear war.

The smallest planet appears after sunset as the waxing Moon reaches First Quarter and star clusters shine in the sky this ...

The constellation Auriga (pronounced or-EYE-guh) the Charioteer, a star pattern known by this name for several thousand years ...

Born at the same time, the star that formed Sirius B started out more massive and evolved more quickly than its companion, ...

Ganymede and Europa transit Jupiter tonight, while Io disappears in an occultation. West Coast observers can catch a double ...

Venus and Jupiter are visible in the evening, while there's a conjunction of Mars and Uranus in the predawn sky.

Saturn dominates the predawn sky, while Mars is rising earlier each day. The Red Planet is still a bit challenging — can you ...

RCW 36 boasts an open cluster of massive young stars at its heart, surrounded by glowing clouds of hydrogen gas.

The Moon sits between bright Venus and Jupiter in the evening sky, tracing out the plane of the ecliptic for all to see.