Curiosity Rover Conducts Rare Experiment to Search for Life on Mars

NASA’s Curiosity rover has embarked on a rare experiment to analyze a Martian rock sample that may contain organic molecules, which are essential components of life as we know it on Earth. Utilizing its last drop of a special chemical, known as tetramethylammonium hydroxide (TMAH), the rover aims to uncover vital information about the planet’s potential to have supported life in the past. This unique experiment comes after a communication blackout known as conjunction, during which Mars was positioned behind the sun from Earth’s perspective.

The Curiosity rover has conducted this specific type of analysis only once in its 13-year mission on Mars. The chemical TMAH is combined with powdered rock to facilitate the detection of carbon-based compounds, which could indicate past life. According to Alex Innanen, an atmospheric scientist at York University, the team took careful precautions to ensure the experiment’s success. “We want to be very certain that everything will go well,” Innanen noted in a mission log. The rover began this critical experiment on February 2, 2024.

Exploring Mars for Signs of Life

Curiosity’s onboard laboratory has only carried two small containers of TMAH throughout its mission, with one previously used nearly six years ago. The current experiment represents a significant opportunity for scientists to investigate organic compounds that standard tests may overlook. Discovering these molecules could help researchers determine whether Mars once had conditions suitable for life and how the chemistry of Earth might emerge on other planets.

In September 2023, NASA announced that a sample collected by the Perseverance rover contained fossilized material possibly created by ancient microorganisms. Nicky Fox, NASA’s associate administrator, remarked, “This finding by our incredible Perseverance rover is the closest we’ve actually come to discovering ancient life on Mars.” However, officials have cautioned that non-biological explanations for these findings are still a possibility.

Curiosity gathered the sample near a drilled hole at a site known as Nevado Sajama, which features fine-grained sedimentary rock believed to have formed under conditions that involved water. This makes it an ideal location for searching for traces of fossilized organic material. The expression “Where there’s water, there’s potential for life” encapsulates the significance of this area for scientists.

To minimize errors during the sample transfer process, the team rehearsed the steps leading up to the experiment. The last time TMAH was used, Curiosity drilled a hole in a clay-rich rock site called Mary Anning, with results revealing a wider range of organic molecules than heating alone would have detected. This previous analysis took approximately seven months to interpret, prompting the team to enhance the experimental design.

Innovating for Mars Exploration

Improvements to the TMAH experiment included redesigning the procedure to better mimic laboratory conditions on Earth. The new three-stage process allows the solvent to interact with the sediment at varying temperatures, which could yield more insightful results. This redesign was delayed by the COVID-19 pandemic but ultimately provided the team with the right opportunity when Curiosity discovered clay minerals in the boxwork region.

The boxwork landscape, characterized by a network of low ridges resembling spiderwebs from above, is believed to have formed from the last trickles of groundwater in the area before it dried up. Researchers are eager to learn more about the fluids that passed through the ridges. Since its launch in 2011, Curiosity has traveled over 352 million miles, with 22.5 miles traversed on the Martian surface.

Despite exhausting its supply of TMAH, Curiosity still has access to another solvent, MTBSTFA, which can be utilized in future analyses. Ashwin Vasavada, Curiosity’s project scientist, mentioned that two out of three phases of the latest experiment have already been completed. “We’re really excited about seeing the results,” he stated. “These are quite complex analyses to interpret and understand, so it will take a few months for the team to be confident in knowing what they’ve found.”

As the rover continues its exploration of Mars, the findings from this experiment could prove pivotal in understanding the planet’s history and its potential for harboring life.