Skip to main content

Atmosphere Pressure Changes Could Explain Mars Methane

One ongoing mystery on Mars is the sporadic detection of atmospheric methane. Since 1999 detections have been made by Earth-based observatories, orbital missions, and on the surface by the Curiosity Rover. However, other missions and observatories have not detected methane at all, and even when detected, the abundances appear to fluctuate seasonally or even daily.

So, where does this intermittent methane come from? A group of scientists have proposed an interesting theory: the methane is being sucked out of the ground by changes in pressure in the Martian atmosphere. The researchers simulated how methane moves underground on Mars through networks of underground fractures and found that seasonal changes can force the methane onto the surface for a short time.

In their paper, published in the Journal of Geophysical Research: Planets, the scientists say their simulations predict short-lived methane pulses prior to sunrise for Mars’ upcoming northern summer period, which is a candidate time frame for Curiosity’s next atmospheric sampling campaign.

“Our work suggests several key time windows for Curiosity to collect data,” said John Ortiz, a graduate student at Los Alamos National Laboratory who led the research team. “We think these offer the best chance of constraining the timing of methane fluctuations, and (hopefully) down the line bringing us closer to understanding where it comes from on Mars.”

The presence of methane (CH4) in the Martian atmosphere is of great interest to planetary scientists and exobiologists because it could indicate present or past microbial life. Or, it could also be related to nonbiological processes, such as volcanism or hydrothermal activity.

The problem with detecting methane is that it doesn’t last long. Once released into the atmosphere, it can be quickly destroyed by natural atmospheric processes. Therefore, any methane detected in Mars’ atmosphere means it must have been released recently, which only adds to the intrigue.

On Earth, most methane is produced by living creatures such as microorganisms in sedimentary strata, or in the guts of ruminants (cows, sheep, deer, etc.). For methane produced through abiotic or non-living processes, there is a high likelihood it could have been produced millions or even billions of years ago, lying trapped in underground rock formations.

But still, finding methane on Mars is a big deal because of the potential for biological sources, such as methanogenic microbes.

This graphic is the result of an analysis that gives a percentage chance of the methane originating in each grid square centered on Gale Crater. Image Credit: Giuranna et al. (2019)

In 2004, the Mars Express Orbiter (MEO) detected methane in the Martian atmosphere. In 2013 and 2014 Curiosity detected spikes in methane in the atmosphere at Gale Crater. Interestingly, MEO detected a methane spike again, at the same location that Curiosity did, only one day later.

Ortiz and his team wanted to better understand Mars’ methane levels, and used high-performance computing clusters to simulate how methane travels through networks of underground fractures, and then released into the atmosphere when driven by atmospheric pressure fluctuations. They also modeled how methane is adsorbed onto the pores of rocks, which is a temperature-dependent process that may contribute to the methane level fluctuations.

The team said their simulations predicted methane pulses from the ground surface into the atmosphere just before the Martian sunrise in the planet’s northern summer season, which just recently ended. This corroborates previous rover data suggesting that methane levels fluctuated not only seasonally, but also daily. With these insights, the Curiosity rover team can figure out when and where to look for methane, which could aid in the rover’s main goal, searching for signs of life.

“Understanding Mars’ methane variations has been highlighted by NASA’s Curiosity team as the next key step towards figuring out where it comes from,” Ortiz said. “There are several challenges associated with meeting that goal, and a big one is knowing what time of a given sol (Martian day) is best for Curiosity to perform an atmospheric sampling experiment.”

Paper: “Sub-diurnal methane variations on Mars driven by barometric pumping and planetary boundary layer evolution.” Journal of Geophysical Research: Planets. DOI: 10.1029/2023JE008043
LANL press release

The post Atmosphere Pressure Changes Could Explain Mars Methane appeared first on Universe Today.



from Universe Today https://ift.tt/SQ0zp73
via IFTTT
Labels:

Comments

Post a Comment

Popular posts from this blog

A Magnetohydrodynamic Drive Could Lead to Fuel Stations on Mars

Within the next fifteen years, NASA, China, and SpaceX plan to send the first crewed missions to Mars. In all three cases, these missions are meant to culminate in the creation of surface habitats that will allow for many returns and – quite possibly – permanent human settlements. This presents numerous challenges, one of the greatest of which is the need for plenty of breathable air and propellant. Both can be manufactured through electrolysis, where electromagnetic fields are applied to water (H 2 O) to create oxygen gas (O 2 ) and liquid hydrogen (LH 2 ). While Mars has ample deposits of water ice on its surface that make this feasible, existing technological solutions fall short of the reliability and efficiency levels required for space exploration. Fortunately, a team of researchers from Georgia Tech has proposed a “ Magnetohydrodynamic Drive for Hydrogen and Oxygen Production in Mars Transfer ” that combines multiple functionalities into a system with no moving parts. This syst...
Post a Comment
Read more

SETI Researchers Double-Checked 1 Million Objects for Signs of Alien Signals

We can’t help ourselves but wonder about life elsewhere in the Universe. Any hint of a biosignature or even a faint, technosignature-like event wrests our attention away from our tumultuous daily affairs. In 1984, our wistful quest took concrete form as SETI, the Search for Extraterrestrial Intelligence . Unfortunately, or maybe fortunately, SETI has turned up nothing. Recently, scientists used a powerful new data system to re-examine data from one million cosmic objects and still came up empty-handed. Did they learn anything from this attempt? This effort used COSMIC , which stands for  Commensal Open-Source Multimode Interferometer Cluster . It’s a signal-processing and algorithm system attached to the Karl G. Jansky  Very Large Array  (VLA) radio astronomy observatory. According to SETI, it’s designed to “search for signals throughout the Galaxy consistent with our understanding of artificial radio emissions. “ Modern astronomy generates vast volumes of data and al...
Post a Comment
Read more

A New Technique Has Dramatically Improved ALMA’s Resolution

To those familiar with optical telescopes, the idea of doing something to achieve higher resolution with their telescope may seem alien, if not, then practically impossible. A telescopes resolution is determined by among other things, its aperture – diameter of the thing that collects light (or electromagnetic radiation) and of course you can’t easily change that. Enter the team at ALMA, the Atacama Large Millimeter Array who have become the first to use the Band 10 receiver and extreme separation of the receivers to boosting its resolution so they can see detail equivalent of detecting a 10 meter long bus on the Moon! The Atacama Large Millimeter/submillimeter Array (otherwise known as ALMA) is based upon interferometer technology which, in its simplest terms, takes a number of telescopes, hooks them together and gives them the same amount of resolution as if the instrument was the same diameter as the distance between the component parts! If that blew your mind then let me explain;...
Post a Comment
Read more