NASA/JPL-Caltech

Welcome to Mars

This might look like a chocolate-chip cookie, but it's actually a zoomed-in view of the ground on Mars where some intriguing rounded formations appear.

NASA's Curiosity rover snapped the fascinating view on Dec. 5. Planetary geologist and Curiosity team member Susanne Schwenzer described the nodule-like rocks as "little round items" in a rover mission update on Monday.

Schwenzer suggested the smooth shapes "could be due to diagenesis or more generally water-rock interaction." Diagenesis refers to the alteration processes that occur after sediment is deposited. Curiosity has been investigating a clay-rich area of Mars. Data gathered there is helping scientists delve into the history of water on Mars.

If you're trying to figure out the scale here, think tiny. The ChemCam Remote Micro-Imager is capable of taking super-close-up images. The ChemCam team analyzes soil and rock composition and investigates weathering processes.

Curiosity has been gifting researchers with a diverse array of rocks lately. "The rich workspace included bedrock, pebbly areas and a brighter float rock of a kind which has been observed frequently in the vicinity," Schwenzer wrote.

NASA has spotted some wonderfully smooth pebbles on Mars before, including one in 2017 that looked like a tiny cannonball.

Curiosity is currently NASA's only operating rover, but it will soon welcome a new friend to the Red Planet. The Mars 2020 rover is scheduled to arrive in early 2021.