Wild Type

The Martian hits theaters today! I’m suspending my usual policy of avoiding opening-day movie crowds and going this afternoon: Andy Weir + Ridley Scott x Matt Damon = too good to wait. But there’s also some exciting non-fiction news from the Red Planet this week. On Monday, NASA confirmed that its Mars Reconnaissance Orbiter (MRO) has found evidence of liquid water.

Streaks on the planet’s slopes, called recurring slope lineae (RSL) have been in researcher’s telescopes since 2011. These lines darken in warmer weather and fade when the temperature drops, giving the impression of ebb and flow. The MRO’s equipment detected hydrated salts in the RSL, which suggests the seasonal change in their appearance may be due to water activity. Researchers identified two potential sources for the water: it could come directly from the atmosphere, or from a seasonal feed of groundwater. Details of the study published in the journal Nature Geoscience.

Mars is still drier than Earth’s most arid desert, posing a tough environment for even microorganisms to survive, but the likely presence of water raises exciting possibilities for both the discovery of extraterrestrial life. It also poses an unexpected challenge: the risk of contaminating Mars. An international organization called the Committee on Space Research (COSPAR) maintains rules for “planetary protection”, intended to prevent exploratory missions from contaminating the environments of other worlds (kind of like the “Prime Directive” from Star Trek). COSPAR considers flowing water areas to be especially sensitive, and landers exploring those regions must meet special standards of cleanliness. The Curiosity Rover wasn’t made to these specifications, so it could be carrying stowaway Earth organisms.

Without samples from the RSLs, it will be much harder to search for signs of life. Some NASA experts argue that radiation and ultraviolet exposure have sterilized Curiosity and made it safe for Mars’ water biomes, but debate continues. Fortunately, science fiction is a great tool for unraveling the ethics of space exploration. I’m sure Mark Watney violated a few COSPAR rules against “contaminating” alien worlds with disco music!