Pluto has five known moons, and it's a bit surprising that New Horizons hasn't found any new ones yet. Newly released images show small moons Nix and Hydra.
And plate tectonics may be essential for life. A new theory of Earth's composition suggests another factor to consider in the search for habitable exoplanets.
The Rosetta team is hoping that a software patch will help re-establish reliable contact with the little Philae lander, lodged somewhere on the comet's surface.
Scientific arguments suggest that alien civilizations should be common in our galaxy. If so, where is everybody? That question is known as the Fermi paradox.
Earth's thick continental crust - the land under our feet - may have risen from the oceans half a billion years earlier than scientists previously thought.
Latest image release from New Horizons team shows Pluto's moon Charon a strange mountain rising out of a depression. They're calling it a “mountain in a moat.”
NASA's OSIRIS-Rex mission is on target for a 2016 launch to near-Earth asteroid Bennu. It will reach Bennu in 2018 and return samples to Earth in 2023.