Planets

New simulations show that Jupiter's massive moon Ganymede was knocked off its axis when it was struck by a roughly 90-mile-wide asteroid around 4 billion years ago. The colossal collision was likely one of the biggest asteroid impacts the solar system has ever seen.

Saturn will enter opposition on Sept. 7 and 8, orbiting on the opposite side of Earth as the sun. Here's everything you need to know to spot Saturn at its peak size and brightness this week.

Astronomers have traced the origins of 200 meteorites to five impact craters in two volcanic regions on Mars, known as Tharsis and Elysium.

Voyager 2, NASA's longest-running mission, explored Neptune during a historic encounter on Aug. 25, 1989, sending back humanity's first close-ups of the planet.

NASA's Chandra X-ray space telescope has created a 3-D map of nearby stars that may help astronomers search for alien planets with the potential for life.

Look east before dawn on Wednesday, Aug. 14, to see the giant planet and the Red Planet just a third of a degree from one another in a rare planetary conjunction.

Scientists examining data from NASA's InSight Lander have revealed the likely presence of an underground reservoir containing enough liquid to cover the planet with a mile of water.

This stunning image of dune fields near Mars' north polar ice cap, taken by NASA's Mars Reconnaissance Orbiter, showcases the impact of polar winds on the Red Planet's landscape.

Astronomers using the James Webb Space Telescope have found that Ariel, a moon of Uranus, has some of the most carbon dioxide-rich deposits in the solar system, hinting at a buried water ocean.