Curiosity is a Mars rover that launched from Earth on November 26, 2011. It landed on the red planet on August 6, 2012, after a 350 million mile journey.
Its mission? To investigate the Martian climate and geology for future human exploration. Specifically, scientists tasked Curiosity with looking for habitable conditions and evidence of water or microbial life.
The Curiosity mission was extended indefinitely in December 2012. NASA is now using Curiosity’s data to study Mars as we prepare for an eventual human mission to the planet.
Curiosity’s curious journey
Curiosity is exploring several regions on Mars. After analyzing soil samples on Vera Rubin Ridge, Curiosity moved into a new area, the Gale Crater, in January 2019.
Gale Crater is a clay-rich area of Mars. This curious crater measures 96 miles wide and has a three-mile-high mountain, Mount Sharp, at its center.
Scientists were excited to analyze this area, which was likely once an ancient lake. After measuring the density of the crater’s rock layers, Curiosity found that Gale Crater was much more porous than previously thought.
Scientists are interested in what lies beneath the Martian surface, which could contain clues to the planet’s mysterious history.
For example, Curiosity also found that Mount Sharp was likely not formed by an impact on the Martian surface. In fact, the mountain appears to be made from sedimentary rock, supporting the hypothesis that Gale Crater may have once been a lake, not an impact crater.
Presence of methane
As Curiosity explored Gale Crater, it made its most significant finding. On June 15, 2013, Curiosity detected a rare methane emission.
The research is only just now coming to light because researchers had to confirm that it was, in fact, a methane emission. After confirming with the EU’s space orbiter and other spectrometer data, NASA confirmed that Curiosity did detect a rare methane emission.
However, Curiosity hasn’t detected a spike in methane in the years since. Scientists aren’t sure how the methane got there. Methane is a key indicator for life; for life, as we know it to exist, methane must be present.
It’s a potential sign that ancient Mars may have been suitable for microorganisms, which produce methane.
But there’s a problem.
Methane doesn’t last long in an atmosphere. It must be produced recently because it evaporates too quickly. Because the methane must have been recently introduced into the air, scientists speculate that the gas is escaping through a vent in the Martian surface.
This isn’t an unusual occurrence on Earth. Continental shifts and tectonic activity release natural gas deposits. This is likely also happening on Mars but to a lesser degree.
Curiosity did find slow tectonic activity below the surface in the icy Martian soil. This is likely the source of the methane that Curiosity detected.
This is a cautious but promising first step in the potential for life on Mars. The methane emission was incredibly large for Martian standards, but it’s still a sporadic event with low methane levels of methane when compared to Earth.
The potential for Martian life
There’s still hope for the potential to find microbial life on Mars.
For example, the Planetary Science Institute is testing microbes’ ability to survive 195 days in soil similar to Martian conditions. Initial tests are promising: the microbes continued to produce methane by feeding off of the nutrients in the soil.
Curiosity is now in an area of Mars that’s rich with clay. With the recent findings of Gale Crater’s geology, it’s only a matter of time before we begin to unravel Mars’ secrets.