Mars, now a dusty world of rusted rock and thin air, once carried enough water to transform its face into something far more familiar. New mapping of ancient river systems indicates that a vast ...

New data is challenging what scientists previously knew about one of the youngest geological features on the Red Planet. That feature is Athabasca Valles, a system of valleys carved into volcanic ...

The interior of Mars is as chunky as a delicious macadamia cookie. A new analysis of the acoustic waves that ripple through and bounce around the red planet's guts reveals that the ancient, early ...

NASA’s Curiosity rover captured a coral-shaped rock on Mars. Though not alive, its shape reveals clues about the planet’s geology. Small discoveries like this help scientists decode Mars’ ancient past ...

Frigid water helped paint Mars red and may have shaped a vast coastline, two new studies into the planet’s history reveal. Scientists have detected a possible ancient beach in Mars’ northern ...

(CNN) — Here’s a look at the exploration of Mars. The United States, Soviet Union and China are the only three countries to land a spacecraft on Mars. There have been nine successful US Mars landings: ...

The findings potentially solve the paradox of how liquid water seems to have persisted on Mars even when the climate grew too cold.

This doesn’t mean Mars causes ice ages on its own. Orbital cycles are only part of the picture. Earth’s oceans, atmosphere, ...