The National Aeronautic Space Association (NASA) launched its ambitious Mars 2020 project in the July of 2020, with the mission aim that stated: “Seek signs of ancient life and collect samples of rock and regolith (broken rock and soil) for possible return to Earth.”
The rover it sent, titled “Perseverance,” along with its remote drone helicopter “Ingenuity,” landed finally on 18th February, 2021 on Mars’ famed Jezero Crater. And the rover has collected its first and second samples within the span of a week.
Rochette and the Volcanic Origins of Mars
A Martian boulder dubbed “Rochette” is where the first pair of rock samples were taken from, reports Live Science . The collected samples were sealed shut in a designated titanium tube, as announced by the mission team members on Twitter.
NASA’s Perseverance rover and Ingenuity helicopter ( EvgeniyQW / Adobe Stock)
Perseverance had made its first attempt to collect a sample on the 5th of August, but its targeted rock turned out to be rather soft, and crumbled under the weight of the percussive drill. Fortunately, Rochette proved to be a sturdier target, and two samples dubbed “Montdenier” and “Montagnac” were successfully collected from it.
“It looks like our first rocks reveal a potentially habitable sustained environment,” said Ken Farley, project scientist for the mission, in a statement on Friday. “It’s a big deal that the water was there for a long time.” Being able to ascertain how long water lay on the lakebed could point to the presence of microbial life , provided the conditions were conducive and the water was there for a long enough time.
The core of Rochette showed that it was volcanic in origin, according to preliminary analysis. It is basaltic in composition, which indicates it might be a product of lava flows. The volcanic origin would help determine accurately the date of formation, taking us back to the days when Mars was volcanologically active. It would also help ascertain the date of the Jezero Crater, believed to have been formed around 3.5 billion years ago, reports Forbes.
Salt minerals too have been spotted within these rocks, as a result of flowing groundwater altering the original composition of the rock, or upon the evaporation of liquid, trapping tiny bubbles of ancient Martian water.
Why Choose Jezero Crater?
Jezero Crater was chosen as the landing site for Perseverance as scientists believe the area was once inundated with water, and home to an ancient river delta . It was chosen after careful examination of 60 other potential landing sites, involving deep data, research, and analysis. A combination of Mission Team members and scientists from around the world spent 5 years on just deciding the landing site.
Jezero Crater. The ancient river can be seen top left, flowing into the river delta within the crater (Justin Cowart / CC BY-NC-SA 2.0 )
The search for prolonged inundation of water and potentially emerging microbial life could confirm the hypothesis of a planet that has, in its long history, gone through periods with water and then without. There is prior evidence of clay minerals being carried by water from the surrounding areas into the lake, reports NASA. The crater also contains high concentrations of calcium, aluminum, and magnesium, telltale indicators of clay sediments and carbonates.
“These samples have high value for future laboratory analysis back on Earth. One day, we may be able to work out the sequence and timing of the environmental conditions that this rock’s minerals represent. This will help answer the big-picture science question of the history and stability of liquid water on Mars,” said Mitch Schulte of NASA Headquarters, the mission’s program scientist.
The crater itself is 45 kilometers (28 miles) wide, and scientists speculate that it was once a 250 meter (820 feet) deep lake. It is on the western edge of a flat plain called Isidis Planitia, lying north of the Martian equator. It is a massive 3,700 kilometers (2,300 miles) from the landing site of NASA’s Curiosity rover , which is designed to explore the Gale crater, and landed 9 years earlier, in 2012. Interestingly, the core design of Perseverance is borrowed from Curiosity, adding its own drill, scientific instruments, 19 cameras, and 2 microphones.
Artist’s rendition of how Jezero Crater may have looked as a lake ( phys.org)
In 2031, Perseverance will attempt to return all collected samples back to Earth. The target is 31 samples minimum, in a plan titled Mars Sample Return (or MSR), with 3 missions spanning 10 years. “The idea of bringing a sample back from Mars goes back decades,” Ken Farley had said in a statement earlier this year.
“We are in a position now where if everything goes according to plan, samples will be coming back to Earth in 2031. That sounds like a long time, but this becoming a reality has always been 10 years away since I was in grad school. Now we are actually doing it.”
Top image: The “Rochette” boulder with two core sample drill holes. Source: Forbes.
