Now deeper in Leo, our satellite skims close to the bright star Regulus, standing east of Jupiter and Mars in the morning sky.

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.

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.

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

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 ...

The Moon passes 5° north of Neptune at 11 P.M. EDT; you can catch the pair in the south around that time, along with Saturn in the southwest, just to the Moon’s lower left. Saturn is visible to the ...