Study predicts best times for Curiosity to sample Mars’ methane

Since methane was first detected in Mars’ ambiance 20 years in the past, scientists have struggled to uncover its origins and the way it’s transported across the Pink Planet. Measurements from atmospheric samples collected by NASA’s Curiosity rover at Gale crater reveal fluctuations in methane ranges over days and seasons, however pinpointing the timing and causes for the variability has proved tough. These emissions, presumably produced by subsurface microbes, may present important proof of life on Mars. Nonetheless, sampling strains Curiosity’s restricted assets, so figuring out each why fluctuations happen and when to finest seize samples is paramount.

In line with a latest examine led by John Ortiz, an environmental engineering doctoral candidate at Johns Hopkins College, barometric pumping may very well be liable for bringing gases from beneath the planet’s floor into its ambiance at irregular however predictable intervals. This natural mechanism may maintain worthwhile data for the Curiosity mission, which is presently in its eleventh 12 months.

“Barometric pumping is a course of through which variations in atmospheric pressure can push and pull gases from underground rock pores as much as the floor,” stated Ortiz, of the Division of Environmental Well being and Engineering. “Similar to on Earth, every day atmospheric pressure modifications on Mars are largely brought on by heating from the sun—cooler air at night time has greater strain, hotter air in the course of the day has decrease strain. The bottom can primarily ‘breathe’ out gases like methane by pushing them as much as the floor by way of fractures when atmospheric pressures are low and pulling them again underground when air strain is excessive.”

The group’s outcomes seem within the Journal of Geophysical Research: Planets. Researchers included Ortiz’s colleagues at Johns Hopkins, Los Alamos Nationwide Laboratory, Purdue College, and the Freshwater Belief.

For his or her investigation, the researchers used laptop fashions to simulate how methane strikes beneath the Martian floor, in addition to the way it mixes inside the ambiance. They then in contrast their simulated methane concentrations with the Curiosity rover’s measurements. As a result of Mars’ climate and atmospheric pressures are a lot much less chaotic than Earth’s, the researchers had been in a position to make predictions of atmospheric methane ranges over time.

One important discovering of the researchers’ computer simulations was a “puff” of methane simply earlier than the Martian dawn—data that might information Curiosity because it performs a sequence of atmospheric sampling experiments as a part of a present marketing campaign to characterize methane fluctuations at Gale crater.

“Our work suggests a number of key time home windows for Curiosity to gather information, every of which has the potential to inform us one thing completely different about methane circulation and transport processes. We predict these supply the very best probability of constraining the timing of methane fluctuations and hopefully down the road bringing us nearer to understanding the place it comes from on Mars,” stated Harihar Rajaram, a professor of environmental well being and engineering at Johns Hopkins and Ortiz’s doctoral adviser.

Authors embody: Kevin Lewis, an affiliate professor at Johns Hopkins College; Phillip Stauffer, a scientist at Los Alamos Nationwide Laboratory; Roger Wiens, a professor at Perdue College; and Dylan Harp, a computational hydrologist at Freshwater Belief.