Earth's satellite sits close to the Red Planet in the predawn sky, before passing both Mars and Jupiter later in the day.

SpaceX flies a national security mission, South Korea's defense agency attempts a demonstration flight, and China lines up four launches.

The event horizon of a nonspinning billion-solar-mass back hole has a radius of 1.8 billion miles — the distance of Uranus from the Sun.

Venus’ reign is coming to an end as Mars and Jupiter enter the scene and the Moon occults Regulus in the southern sky this ...

Stunning face-on spiral M74 is visible after dark this evening, showing off its bright nucleus and fainter asymmetrical arms ...

Saturn is visible as darkness falls with Neptune nearby, the Full Moon crosses the Pleiades, and Mars and Jupiter dominate before dawn.

Our satellite stands in Cancer the Crab, not far from M44 and ready to approach western Leo to pass the planets there.

Our satellite passes several planets while Venus meets Spica in a close conjunction and spooky season culminates in the sky ...

This crescent-shaped cluster shines in northern Cassiopeia, visible all night long as the stars wheel around the North ...

The Red Planet reaches the border of Cancer and Leo; tomorrow it will have crossed the line into the Lion, sharing it with ...

October’s bright Full Moon offers an excellent observing target, allowing you to trace the rays thrown out by ancient impacts ...

The Moon passes 5° north of Uranus at 6 A.M. EDT this morning. You’ll find our satellite hanging above the Pleiades (M45) in ...