COLONIZATION ADVANCES: A catalyst that destroys perchlorate in water could clean Martian soil. “Perchlorate, a negative ion consisting of one chlorine atom bonded to four oxygen atoms, occurs naturally in some soils on Earth, and is especially abundant in Martian soil. . . . The new catalyst reduces perchlorate in a wide concentration range, from less than 1 milligram per liter to 10 grams per liter. This makes it suitable for use in various scenarios, including remediating contaminated groundwater, treating heavily contaminated wastewater from explosives manufacturing, and making Mars habitable.”