Astronomers have detected water vapor and evidence of exotic clouds in the atmosphere of a Neptune-mass planet known as HAT-P-26b.
Saturn's bizarre "eye" — the ringed planet's north polar vortex and surrounding hexagonal jet stream — stares impassively out into space in an amazing photo by NASA's Saturn-orbiting Cassini probe.
The record-breaking, hush-hush mission of the U.S. Air Force's robotic X-37B space plane is finally over.
The first fleet of robotic spacecraft that humanity launches to explore nearby exoplanets may include a few kamikazes.
For the second week in a row, the United States Air Force has tested an unarmed intercontinental ballistic missile (ICBM).
A mysterious abundance of high-energy light near the Milky Way's core likely isn't a sign of elusive dark matter after all, a new study suggests.
The U.S. Air Force's robotic X-37B space plane has now been circling Earth for 700 days on its latest hush-hush mission.
The same sorts of chemical reactions that sustain life near deep-sea hydrothermal vents here on Earth could be occurring within Enceladus' subsurface ocean, a new study suggests.
Bright auroras light up Uranus' atmosphere in two newly released photos, which combine observations by NASA's Hubble Space Telescope and the agency's Voyager 2 probe.
Hubble snapped the photo on Monday (April 3), just four days before Jupiter comes into "opposition," forming a straight line with Earth and the sun (with Earth in the middle).
Neil deGrasse Tyson is willing to fly to Mars with SpaceX, as long as company founder and CEO Elon Musk meets a few key conditions.
An ancient brown dwarf about 750 light-years from Earth is the most massive and purest such "failed star" ever discovered, a new study suggests.
The current mission of the U.S. Air Force's robotic X-37B space plane is now the longest in the clandestine program's history.
If the robotic vehicle stays aloft until March 25, it will break the X-37B mission-duration mark of 674 days, which was set back in October 2014.
Bizarre flashes of cosmic light may actually be generated by advanced alien civilizations, as a way to accelerate interstellar spacecraft to tremendous speeds, a new study suggests.
The NROL-79 satellite launched atop a United Launch Alliance Atlas V rocket at 12:49 p.m. EST (1749 GMT) today, rising off a pad at Vandenberg Air Force Base in California.
The dwarf planet Ceres may once have harbored many ice volcanoes, all but one of which have flattened out and vanished into the dwarf planet's surface, a new study suggests.