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

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

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.

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

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

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

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

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