Pulses of methane on Mars could be caused by changes in atmospheric pressure

New research shows that fluctuations in atmospheric pressure that draw gases from underground could be responsible for releasing methane from underground into Mars’ atmosphere; Knowing when and where to look for methane can help the Curiosity rover search for signs of life.

“Understanding methane variations on Mars has been highlighted by NASA’s Curiosity team as the next key step in determining where it comes from,” said John Ortiz, a graduate student at Los Alamos National Laboratory who led the research team. “There are several challenges associated with achieving this goal, and one of the most important is knowing at what time of a given sol (Martian day) it is best for Curiosity to perform an atmospheric sampling experiment .”

The article was published on January 22 in the Geophysical Research Journal: Planets.

One of the main goals of NASA’s Mars missions, including Curiosity and Perseverance, is to detect and understand past or present signs of life, such as methane. However, because the source of methane on Mars is likely underground, short-term variations in atmospheric methane levels have posed a research challenge.

To better understand methane levels on Mars, Ortiz and his team used high-performance computing clusters to simulate how methane passes through underground fracture networks and is released into the atmosphere, where it then mixes into the atmospheric column. They also modeled how methane is adsorbed onto rock pores, a temperature-dependent process that can contribute to methane level fluctuations.

Their simulations predicted pulses of methane from the ground surface into the atmosphere just before sunrise on Mars, during the planet’s northern summer season, which has just ended. This supports previous data from the rover suggesting that methane levels fluctuated not only seasonally, but also daily.

This valuable data helps inform the Curiosity rover’s ongoing sampling campaign.

“Our work suggests several key time windows for Curiosity to collect data. We believe these offer the best chance of constraining the timing of methane fluctuations and (hopefully) bringing us closer to understanding where it comes from on Mars,” Ortiz said. said.