Mars

This pit crater making recent headlines may open into a larger cave that could provide a sheltered environment for both astronauts and hypothetical Martian life.

Potentially hazardous asteroids pose a risk to Mars missions, but they can also yield insight into the history of the Red Planet and the early solar system, new research suggests.

Previously unpublished photos of Mars' moon Phobos hint that the mysterious satellite may actually be a trapped comet — or perhaps just a piece of one, along with its twin moon Deimos.

Newfound rocks on Mars suggest the planet may have once sported an oxygen-rich atmosphere, making it more Earth-like and hospitable to life than previously thought.

Mars has had frequent planet-wide auroras in recent months, including an unprecedented trio of events in February. Experts say the sudden increase is the result of the ongoing solar maximum.

Every spring, creepy black 'spiders' sprout up on Mars as buried carbon dioxide ice releases dusty geysers of gas. New ESA images show the phenomenon has begun in the strange Inca City formation.

NASA's plan to retrieve as many as 30 geological samples from Mars is getting a major rewrite, agency officials said on Monday. The initial plan, which would not return the samples to Earth until 2040, was deemed "too expensive" and "unacceptably too long."

An object that slammed into Mars roughly 2.3 million years ago created 2 billion smaller craters around the main Corinto impact crater, near the Red Planet's equator.

A newly discovered volcano near Mars' "Labyrinth of Night" could be a "prime" spot to search for life on the Red Planet, scientists say.

NASA's Mars Curiosity rover hides in plain sight in this aerial photo of the treacherous Martian landscape.