Planetary Science

An impact with a protoplanet called Theia 4.5 billion years ago seems to have left remnants deep inside Earth

Fresh investigations find that the Red Planet’s liquid-metal core is smaller than scientists thought

NASA’s Lucy mission is starting its science studies way ahead of schedule

As space agencies turn their gaze to the moon, we need to consider what werewolves might mean for lunar exploration—and vice versa

Defunct satellites and other pieces of orbital debris are pumping metals into Earth’s fragile upper atmosphere, with effects unknown

Images from each and every spacecraft now orbiting Mars have ruled out a meteorite strike as the cause of a 4.7-magnitude marsquake, the strongest temblor ever detected beyond Earth

The formation of Pangaea Ultima some 250 million years from now would be bad news for mammalian life. But whether it would mean the end for mammals—or whether the supercontinent will form at all—is far from certain

NASA’s Psyche mission is on its way to a heavy-metal asteroid of the same name—a type of object that scientists have never seen up close before

When the sun gets feisty, Earth’s atmosphere can literally light up. But seeing the resulting aurora isn’t always easy

OSIRIS-REx’s treasure trove from asteroid Bennu includes material rich in water and carbon

NASA’s Perseverance rover has collected valuable samples, but a new report says the plan to fetch them is unworkable

NASA has reversed course on plans to curtail the New Horizons spacecraft’s planetary science studies following a rebellion among the mission’s leaders