By Calvin J.
NASA’s Curiosity rover – armed with its 2-meter-long arms, a radioactive thermoelectric generator, and its invaluable chemistry sets, began its long hunt for ancient Martian life back in the summer of 2012. Being one of NASA’s most ambitious projects to date, Curiosity was the centerpiece of the Mars Science Laboratory. Its mission was to survey the climate and geology of Mars, as well as to determine whether the planet may have been capable of supporting life. At the size of a small SUV and weighing in at over 2,000 pounds, there was little that could stand in its path – or so we thought. Now 5 years later, with its wheels punctured and the rover’s drill broken beyond repair, progress has fallen far behind schedule. With many precious Martian samples yet to be collected and analyzed, Curiosity might finally be running out of time.
Curiosity hit its first snag back in 2014 when tire damage was much more severe than NASA had originally anticipated. Researchers then began to re-evaluate their approach, with the rover spending less time surveying Martian land and more time searching for signs of life. However, progress remain slowed, as Curiosity’s movement speed had to be reduced to prevent further damage to its already weathered wheels. Despite the setback, scientists hit a major breakthrough later that year, when Curiosity finally made its way to the Murray formation, a mudstone ridge thought to be a lakebed that formed over 3 billion years ago. Curiosity had been drilling out samples for testing in its Sample Analysis at Mars (SAM) instrument, a giant easy-bake oven for astro-physicists. Inside, the rocks were vaporized at up to 11,000 °C, with the gasses produced then used to determine the types of elements and compounds that made up the sample. However, the rover was instructed to perform only the most critical of experiments, as it was only equipped with 74 single use chemistry sets. Despite its limited capacity, the data payout so far has been more than worthwhile. At previous sites, Curiosity had already identified the presence of sulfur, nitrogen, hydrogen, oxygen, phosphorous and carbon, all fundamental building blocks of life. The rover even found multiple methane gas deposits, a possible byproduct of early microbes. At the Murray site, scientists later identified several sulphur-containing organic compounds at unexpectedly high concentrations. Something researchers had never encountered before.
Even more intriguing were several molecules resembling long-chain fatty acids. Living things love churning out lipids in long even chains with 12, 14, 16, or 18 carbons. Identifying these long chain fatty acids would be a ground breaking discovery, suggesting the likely existence of ancient life on Mars. However, to differentiate Martian life from a possible earthly contaminant, further analyses had to be done. But the chemical tests needed to follow up these results were held back when the rover’s drill mysteriously broke down in late 2016. NASA engineers spent over 2 weeks attempting remote repairs, but with little success. Engineers believe that the drill’s brakes aren’t releasing due to Martian soil or metal shavings being caught in the drill arm. While the drill arm remains occasionally operational, although only for short periods, the rover can still rely on its scooping arm for collecting soft dirt and rocks from exposed sampling sites. With no way to repair the drill arm, researchers eventually decided to move Curiosity onto the next promising site on its itinerary. Having used only 29 of its 74 chemistry sets in the past 5 years, researchers are determined to speed up progress and not have the remaining kits be left to waste. Curiosity is now working its way up the slopes of Aeolis Mons, a 5,000m tall mountain peak rising out of the Gale crater. On it is an iron-rich hill that may have been home to ancient microbes as well as a formation of clay-rich mudstone that may contain preserved carbon molecules.
Curiosity has been a monumental milestone for space exploration, and as it prepares to celebrate its 5th anniversary on Mars this coming August, NASA has already begun drawing plans for its next rover mission, Mars 2020. Scientists have travelled in flocks to a 3-day workshop hosted in Monrovia, California to debate potential landing sites for Curiosity’s younger sibling. Packed with heaps of new instruments including a ground penetrating imager, RIMFAX (Radar Imager for Mars’ Subsurface Exploration), and NASA’s all new MOXIE (Mars OXygen In situ resource utilization Experiment), scientists are aiming for more than just uncovering Mars’ past. NASA aims to test their new technology for producing oxygen from carbon dioxide on the surface of the red planet, laying the foundation for a day when humans can finally set foot on Martian soil.
Checkout out the amazing photos captured by the Curiosity rover and its weekly updates at NASA’s website
Find updates on landing sites and new technology for NASA’s next rover mission Mars 2020 here
Featured image obtained from NASA/JPL Caltech