Why pummeled planets may be promising abodes for alien life

Cosmic impacts may create water-hosting cracks and pores in a planet's crust.

 

Cosmic impacts, such as the one that created this fresh crater on Mars sometime between September 2016 and February 2019, increase the porosity of planetary crusts, creating cracks and fissures that could host water — and perhaps life. (Image credit: NASA/JPL/University of Arizona)

Cosmic impacts can make planets and moons more porous than previously thought, potentially boosting their ability to host life, a new study finds.

Our moon's pockmarked surface is a testament to just how often cosmic impacts strike the planets, moons and other major bodies within the solar system. The cracks and pores that result from such pummeling can theoretically host water and potentially even microbial life.

In 2012, NASA's Gravity Recovery and Interior Laboratory (GRAIL) spacecraft revealed that the crust of the moon is much less dense, and therefore more porous, than previously thought. The uppermost 2.5 miles (4 kilometers) of lunar highland crust is about 12% empty space, and down to depths of about 12 miles (20 km), the lunar crust still has a porosity of about 4%, the mission determined.