The morning of Monday, October 3, 2005, sky-watchers in Africa and Europe witnessed a seldom seen annular eclipse, in which the moon passes in front of the sun to create a blazing ring in the sky.

Astronomers have found a massive "big baby" galaxy near the limits of the observable universe, raising questions about established theories of galactic formation.

Astronomers say they have found invisible "dark matter" in an unexpected part of space, ramping up the debate about the nature of the mysterious material.

High-tech animation brings the projected 2018 moon mission to life—from blastoff to lunar touchdown to return.

NASA's illustrated mission plan gives you a glimpse into the next generation of space travel.

The mystery of time and the possibilities of traveling through it raise some of the thorniest questions in physics. So why are a growing number of scientists grappling with the issue?

Pursuing a solar system whodunit, scientists say they may have identified the source of a cataclysmic asteroid bombardment that pummeled Earth some 3.9 billion years ago.

Tons of cosmic dust deposited in the atmosphere by vaporizing meteors may influence Earth's weather more than thought, a recent study suggests.

Rockets may be the rage for space travel today, but space elevators may replace them, lifting humans and cargo into space at lower cost and risk.

Its name sounds like a junkyard rust-bucket, but astronomers say 87 Sylvia is part of something special: the first triple asteroid system ever observed.

The dangerous phenomenon of space weather could jeopardize plans for a manned mission to Mars, a new study reports.

The space shuttle touched down successfully in California, but safety concerns still loom large at NASA.

Life on Mars? Who knows? Ice on Mars? Most definitely—and now we've got more cold, hard evidence.

A large object skirting the fringes of the solar system has been discovered by astronomers in Spain and the U.S.

NASA's scaled-back spacecraft-sterilization process may be helping contaminate Martian life before we even discover it, scientists say.