Hunting for microbial life throughout the solar system

Abstract

A robotic lander surveys a frosty landscape near the northern pole of Mars sometime in the 2020s. Revving up a powerful 1-meter drill, it bores into the polar subsurface, extracts a sample, and runs it through a battery of cleverly designed instruments. Maybe, just maybe, it uncovers the chemical residues of living organisms. Jupiter’s icy moon Europa, seen here in enhanced color based on images from the 1990s Galileo mission, is among the candidates for harboring microbial life. Image courtesy of NASA/JPL-Caltech/SETI Institute. This is the proposed Icebreaker Life mission, a couch-sized lander that would till through the same frozen soil visited by NASA’s Phoenix spacecraft in 2008 to find evidence of ancient microbes (1). Icebreaker is not alone. Within the astrobiological community, there is a growing consensus that it’s time to directly hunt for life elsewhere in the solar system. No such experiment has been attempted since the 1976 twin Viking landers’ life-detection instruments turned up inconclusive results on Mars (2). But this year, NASA put out a call to develop technology to go to another world and look for signatures of microbial life, the first such solicitation in more than 40 years. “We’ve got places that are so intriguing that it’s becoming much more compelling to look for life,” says atmospheric scientist Hunter Waite of the Southwest Research Institute in San Antonio, TX. And in October, the National Academies of Sciences, Engineering, and Medicine released a detailed report, titled An Astrobiology Strategy for the Search for Life in the Universe , urging NASA to make astrobiology an integral part of a broad range of future missions (3). Mars is the nearest target. Two discoveries over the summer reinforced its potential for hosting life—a possible reservoir of briny water that lies beneath its ice cap and organic material …