Long-ago impacts tossed up the floors of an ancient ocean on the Red Planet and carried debris to the landing site of NASA’s Viking 1 lander.
Mysterious spots that scientists thought were subsurface lakes beneath the Martian south pole may instead be ancient clay deposits.
Astronomers find more bright spots underneath Mars's south polar cap, but could they really be subterranean lakes?
A new study suggests that by 3 billion years ago, most of the Red Planet’s water was locked away in minerals, and it has stayed there ever since.
New analysis of data from the European Space Agency's Mars Express orbiter strengthens the case for salty lakes underneath Mars's south polar cap.
A radar instrument on one of the oldest operational Mars orbiters has discovered possible evidence of liquid water on Mars.