Methane is found in abundance on Earth; however, on Mars, it’s pretty mysterious. The methane readings from the Red Planet have been puzzling scientists for quite some time. Now, NASA might be closer to finding out the answers to the gas on Mars. They have found that the time of day has a huge impact on the detections of the gas.
Methane is an area of interest because it can be a byproduct of living things, including microbes. Scientists are working on figuring out if the Red Planet once fostered microbial life, or if microbes can survive there now. But the gas could have a geologic origin as well.
Present on surface but not in atmosphere
What’s surprising about the gas on Mars is that NASA’s Curiosity rover has detected it near the Gale Crater, but ESA’s ExoMars Trace Gas Orbiter spacecraft hasn’t found the gas up in the atmosphere. This is what attracts the interest of scientists.
Curiosity’s Tunable Laser Spectrometer instrument is basically a portable chemistry lab. It usually detects a small amount of methane NASA describes as “equivalent to about a pinch of salt diluted in an Olympic-size swimming pool.” The instrument detected a good spike in the methane levels, back in 2019.
ESA’s ExoMars orbiter arrived on the planet in 2016 but wasn’t able to see what Curiosity has. “But when the European team announced that it saw no methane, I was definitely shocked,” said Chris Webster, TLS instrument lead in a NASA statement.
What’s destroying methane?
The discrepancy might come down to the times of day when the orbiter and rover function. The TLS on the rover works at night so it doesn’t conflict with other instruments onboard. The observations are made by the orbiter during the day when there’s sunlight. There’s a possibility that methane pools near the surface are calm at night but dissipate heat during the daytime, making the gas invisible to the spacecraft.
The Curiosity team tested this idea by measuring the gas in the daytime, and the gas actually disappeared during the day. The findings are published in the journal Astronomy and Astrophysics.
The scientists now want to find the reason that’s destroying methane. “We need to determine whether there’s a faster destruction mechanism than normal to fully reconcile the data sets from the rover and the orbiter,” said Webster.
