Red Planet, Blue Planet

Image of astronaut with red mountains behind him.

Mars is the RED planet … right?

This is Sandra Tsing Loh with the Loh Down on Science.

Snaps from NASA’s Perseverance rover show a dry, dusty red landscape. But Mars used to be BLUE with water! Possibly as much as half the Atlantic Ocean. Where’d it go?

Enter Eva Scheller from the California Institute of Technology and colleagues. The team collected chemical measurements from Mars rovers and satellites. Then, they ran them through computer models to simulate past climates on Mars. They modeled volcanic gases, water availability, and atmospheric changes. This let scientists calculate how much water disappeared.

Scientists previously thought that the water evaporated into space. But according to the models, most did NOT go anywhere! Thirty to NINETY-NINE percent may still be trapped in Mars’ crust. The water mixed with rock, formed clay, and combined with minerals. 

So if Mars had water – did it also have life? Still a mystery! Scientists continue searching by studying the carbon and nitrogen found on Mars – two important chemicals for life.

Hmmm . . . could all those take out containers found strewn across Mars provide a clue — NOOO!!!

Reference: Scheller, E. L., Ehlmann, B. L., Hu, R., Adams, D. J., & Yung, Y. L. (2021). Long-term drying of Mars by sequestration of ocean-scale volumes of water in the crust. Science (New York, N.Y.), 372(6537), 56–62.