Perchlorate, a toxic substance found in Mars dirt, could help the bacterium Sporosarcina pasteurii strengthen bonds between particles of regolith.
"You need so much water that we think these could be evidence of an ancient warmer and wetter climate where there was rain falling for millions of years."
Even though the Red Planet's atmosphere is thin, wind is still one of Mars' most relentless sculptors.
Ancient shoreline features hint that water on Mars once formed a vast ocean.
MAVEN was built to last in orbit until 2030 — that's not looking likely anymore.
"Without Mars, Earth's orbit would be missing major climate cycles. What would humans and other animals even look like if Mars weren't there?"
The findings potentially solve the paradox of how liquid water seems to have persisted on Mars even when the climate grew too cold.
Exploration advocates are pushing back against the planned cancellation of NASA's Mars sample return project, saying it could potentially find evidence of Red Planet life.
"The Chinese may well beat the U.S. with a grab sample."
Outside Earth's protection, space travellers will be routinely exposed.