Is our solar system's Oort Cloud in danger of being stirred up by a passing star? A fresh analysis of Hipparcos observations argue that the answer is most likely "yes" — but not for another 1.4 million years.

On March 15 a distinguished panel discussed the future of human spaceflight at New York's Hayden Planetarium.

On March 7th, the European orbiter Mars Express had a close encounter with a little moon about which scientists have big questions.

Day in, day out, the radio antennas of NASA's "Deep Space Network" handshake with dozens of spacecraft across the solar system. Now the network's three stations are getting improvements that will keep them operating for decades.

Don't let its graceful spiral form fool you: our home galaxy is a cannibal. It's long been accused of having gobbled up smaller dwarf galaxies in its vicinity — and two new observations make an ironclad case for the prosecution.

Eerie and elusive, the zodiacal light is created from sunlight glinting off countless dust particles in the inner solar system. At last, astronomers have figured out where all that grit comes from.

In the time it takes you to read this news story, the ultra-tightly paired stars known as HM Cancri will have completely spun around each other.

Do you want the power of a serious telescope without the expense and headaches? Find out how to rent time on a remote telescope and access it over the internet.

Globe at Night, an effort to measure light pollution around the world, runs from March 3-16, 2010. Will you help meet this year's target of 15,000 more participants?

Geologists once believed the Moon was utterly dry. But just-announced results argue that abundant water ice lies stashed inside lunar craters near the north pole.

All the major amateur and professional telescopes in Chile are in good working order despite Saturday's powerful earthquake.

One year after launch, NASA’s Kepler mission draws out the brainpower of the astronomical community to solve a stellar paradox.

Zipping outward at more than 36,000 miles per hour, NASA's New Horizons spacecraft has reached a point where it's closer to its target, Pluto, than it is to the Sun. Only 1½ billion miles to go!

It's taken some 10 billion years, but a compact group of small galaxies is at last merging into a single big one.