Journal Highlights

History of Water on Mars’s Surface Is Longer Than We Thought

Research Spotlight—

Curiosity’s two-step heating experiment of mudstone at Gale crater reveals minerals that formed in the presence of water less than 3 billion years ago.

On the basis of studies of impact crater densities on Mars’s surface, scientists have separated the Red Planet’s geologic history into three broad divisions, the most recent of which is the Amazonian epoch.

Because of the lack of available samples to date directly, however, the numerical ages of these divisions and their associated features have yet to be precisely determined.

Now Martin et al. have developed a promising new method to remotely date materials on Mars’s surface using the potassium-argon radiometric technique. Following a previous experiment that harnessed the combined capabilities of three instruments on board NASA’s Curiosity rover to successfully date a mudstone collected at Gale crater early in the mission, the team determined the ages of both the primary and secondary materials in a later mudstone sample. The rover collected this specimen, known as Mojave 2, from the Pahrump Hills, whose thin layers appear to have been deposited in the bottom of a lake that once filled the 154-kilometer-wide crater....more

-- Terri Cook, Freelance Writer,