When you buy through links on our articles, Future and its syndication partners may earn a commission.NASA’s Perseverance Mars rover captured this image of “Santa Cruz,” a hill inside the Red Planet’s Jezero Crater, on April 29, 2021. | Credit: NASA/JPL-Caltech/ASU/MSSSMars might have its own defense mechanism against life from Earth, in a kind of reverse of “The War of the Worlds” scenario that could help protect the Red Planet from contamination by terrestrial bugs.Scientists led by Corien Bakermans, a professor of microbiology at Penn State University, were experimenting with exposing tardigrades, which are microscopic animals nicknamed “water bears” that grow to at most half a millimeter in length, to simulants of Martian regolith.AdvertisementAdvertisementThe intention was to determine how well tardigrades did in the regolith, with an eye on one day converting Martian regolith — which is dead, inorganic dirt — into organic soil in which plants can grow. For that to happen, life needs to be able to flourish in the regolith in order to help fertilize it. Think of microbes and earthworms in Earth’s soil, continually processing the soil to keep it healthy.The microscope images of tardigrades in the top row are active in Earth sand. The four on the bottom are active in Martian simulant regolith. | Credit: Corien Bakermans/Penn StateSimulants are representations of real Martian regolith. Because we have no samples of Martian regolith on Earth, scientists are forced to replicate it in simulants based on readings of its chemical composition by Mars rovers. In particular, Bakermans’ team used two simulants, both informed by measurements from NASA’s Curiosity rover, which is exploring Gale Crater on Mars.One of the simulants, known as MGS-1, is designed to mimic the general properties of regolith across Mars. The other simulant, OUCM-1, is designed to more specifically represent the Rocknest area in Gale Crater, where Curiosity took the sample that the simulant is based on.”We know a lot about bacteria and fungi in simulated regolith, but very little about how they impact animals — even microscopic animals, like tardigrades,” said Bakermans in a statement …
