"There is likely a threshold on the size requirements of rocky planets to retain enough water to enable habitability and plate tectonics..."
A form of clay called smectites, not water, probably accounts for bright radar reflections under the south polar cap of Mars, researchers report.
New findings confirm "Mars presumably was once completely molten before dividing into the crust, mantle, and core we see today, but that these are different from Earth's."
Volcanoes may have erupted on Mars as recently as 50,000 years ago. The finding raises the possibility of recently habitable conditions below the surface.
Icy clouds could have kept early Mars warm enough to form rivers and lakes, a new study using computer models suggests.
After completing a confined 520-day simulated mission to Mars, researchers discovered significant changes in the crew's gut microbiota.
Glacial runoff appears to have fed an ancient crater lake on Mars, boosting the idea that the red planet had a cold and icy past.
New research suggests tiny sparks are possible on Mars, and that "future colonists may find a world modified by static electricity in subtle ways."
New research used spots on Earth, including Iceland and Idaho, to study the seasons on ancient Mars.
Researchers may have come up with a solution to one of the most pressing challenges of a Mars voyage: How do we get back?