A clay mineral known as smectite could hold a substantial portion of the water missing from Mars, according to new research from Binghamton University, State University of New York.

Rivers and streams once flowed across the surface of Mars, etching channels still evident on the planet's surface today. Water in lakes once lapped ancient shores. But today, Mars' red sands appear bone-dry. Where did all that water go?

Some of that water is trapped in the planet's polar ice caps, which behave like stone due to Mars' frigid temperatures. The rest may have gone underground, locked inside clay minerals such as smectite.

New research from Binghamton University Geological Sciences and Environmental Studies Professor David Jenkins and former graduate student Brittany DePasquale provides information on how deep smectite could occur in the surface rocks of Mars. They found that iron-rich smectite, the least-stable form of smectite, can form to depths up to 30 km, much deeper than others might have predicted. In view of this rather robust stability for smectite, it appears that clay minerals are able to receive and store the missing water on Mars.

Now is the best time to get a glimpse of Comet C/2021 A1, better known as Comet Leonard. It's named for its discoverer, Gregory Leonard, a senior research specialist at the University of Arizona Lunar and Planetary Laboratory.

Every night with clear skies, astronomers with LPL's Catalina Sky Survey scan the sky for near-Earth asteroids—space rocks with the potential of venturing close to Earth at some point.

During one such routine observation run on Jan. 3, Leonard spotted a fuzzy patch of light tracking across the starfield background in a sequence of four images taken with the 1.5-meter telescope at the summit of Mount Lemmon.