Mars Crater History Shows Break From Asteroid Impacts In Early Solar System

Mars was bombarded with asteroids and other objects during its youth, carving out craters from its surface, but at least it got a little breather of 400 million years.

Researchers say there weren’t any large impacts on Mars during that lull, and it lines up with the histories of the rest of the inner solar system. A study in the journal Nature Geoscience estimates the quiet period to have happened 4.1 billion to 4.4 billion years ago — compared to Mars’ age of about 4.5 billion years — and separated the planet’s early bombardment from another series referred to as the late heavy bombardment.

Read: Did a Triple Asteroid Make This Mars Crater?

Scientists from the Southwest Research Institute and the University of Arizona studied large basins on Mars, including the most ancient among them, the 6,000-mile-wide Borealis. Comparing their analysis to the known ages of those basins, they determined no other features on Mars caused by large impacts could have formed during the lull.

Part of the aging information about Borealis came from “impact fragments from Mars that ultimately arrived on Earth,” said Bill Bottke, the study’s lead author.

“The new results reveal that Mars’ impact history closely parallels the bombardment histories we’ve inferred for the Moon, the asteroid belt, and the planet Mercury,” Bottke said in a statement from the Southwest Research Institute. “The lull itself is an important period in the evolution of Mars and other planets.”

See also:

Asteroids Near Mars Are Actually the Bones of a Destroyed Planet

Places on Earth That Are a Lot Like Mars