We met Kathryn Stack Morgan, Research Scientist at the Jet Propulsion Laboratory (NASA JPL) inPasadena (California). Morgan is also theDeputy Project Scientist of the Mars 2020 rover mission, and she has been a member of the Mars Science Laboratory (MSL) Science Team since 2012.
NASA’s Mars 2020 mission brought the Perseverance rover and Mars helicopter Ingenuity to the surface of Mars on February 18, 2021. The Perseverance rover is located in the Jezero crater near the delta of the ancient Martian river, where 3 billion years ago water flowed. One of the rover’s main goals is to take rock samples for analysis on Earth. The next mission, NASA/ESA’s Mars Sample Return, will take those samples collected by Perseverance rover and, via a lander, small rocket and orbiter, will bring them to Earth within 2033.
What are the most promising rocks for the research of life on Mars, found by Perseverance rover? I’ve read that the rocks – called Berea – come from an area well beyond the confines of Jezero Crater and are also rich in carbonate. Why are those rocks very important for Mars Sample Return Mission?
We have found evidence for potential habitable conditions and environments within all of the samples that Perseverance has collected, including both the igneous rocks (rocks formed from molten magma) and sedimentary rocks (rocks made up of pieces of other rocks or precipitated from water). For example, we have evidence that water flowed through the igneous rocks that we explored and sampled on the crater floor, interacting with the minerals and precipitating salts in voids within the rocks. These water and mineral interactions could have provided habitable microenvironments where ancient microbial life could have existed. We’ve also collected several different types of sedimentary rock that were deposited and formed in the presence of water, with all the ingredients needed to support microbial life.
Several of our igneous and sedimentary samples contain carbonate, a mineral containing carbon and oxygen that typically forms in the presence on water. Carbonate minerals are good recorders of environmental conditions at the time they form, so they have the exciting potential to advance our understanding of the ancient climate on Mars. On Earth, the formation of carbonate minerals is often directly or indirectly associated with the influence of living organisms. We don’t know if that was the case for carbonates on Mars, but it will be exciting to find out when these samples come back to Earth.
By studying Martian rocks, we can understand how Mars’ climate has changed. When there were rivers full of water on Mars, was the climate perfect for life?
Understanding the climate of ancient Mars and how it changed over time is an ongoing area of active research in the science community. Using a combination of orbiter and rover data, we now know that a diversity of habitable environments containing the ingredients to support life as we know it—i.e., water, organic compounds, a source of energy—existed on Mars in the past. While observations from our recent rover missions to Mars are consistent with a wet, warm, and habitable Mars, there is still considerable debate within the Mars community about whether Mars in the past was predominantly warm and wet or cold and dry. Either way, we are optimistic that life could have existed on Mars in the ancient past.
Are there any differences between the rocks studied by Curiosity Mars Rovers and rocks studied by Perseverance Mars Rover? Does Mars have the same rocks everywhere or does every part of the planet have a different rock?
One of the biggest differences between the rocks studied by the Curiosity rover in Gale crater and those studied by Perseverance in Jezero crater is that Perseverance has explored both in-place igneous rocks formed by lava or molten rock deep in the crust and sedimentary rocks deposited in water environments. Curiosity, meanwhile, has focused its exploration on a 5 km mound of sedimentary rock. Although Perseverance has been able to study a diversity of rocks in its landing site, Curiosity has had great success examining a long record of time preserved in the rocks of the Gale mound.
Mars was long thought to be a planet dominated by volcanic processes, but recent observations in the past twenty plus years have revealed a diverse record of sedimentary rocks representing deposition by lakes, deltas, rivers, and the wind at the surface of Mars. Although there are often some basic similarities between rocks explored at different places on Mars (particularly related to their composition and the types of minerals we observe), the Martian rock record is definitely diverse and variable from place to place!
What do you like most of your job? What are the emotions that you feel when you study a planet 60-200 million kilometers away from the Earth?
Every day presents a new challenge, whether it’s trying to figure out how to build the best plan to send to the rover, having discussions about the rover’s long-term strategy, or handling the logistics of running a large team with a lot of different opinions and experiences. There is never a dull moment on a rover team! Like any job, this job comes with highs and lows, moments of frustration, and feelings of pride and accomplishment. But there’s nothing like stepping back at the end of the day and reminding myself that I’m part of a much larger quest to answer some of the most fundamental questions we, as humans, have about the history of our solar system and the origin of life.
What do you expect from the Mars Sample Return mission? Will this mission teach the whole world that the impossible can become possible? In my opinion it will also be a great inspiration for children and young people.
Mars Sample Return will open up entire new fields of planetary science, and will have a lasting impact on generations of scientists and students to come. And then there’s the potential paradigm shift that could result if we discover evidence of ancient martian life in the samples that Persevearnce has collected. Our motto at JPL is “Dare Mighty Things,” and the Mars Sample Return campaign is one of the mightiest things we have dared so far, involving an international and collaborative effort. The children and young people now will likely be the PhD students and scientists who will study these samples when they come back to Earth, so in a lot of ways these samples are really for them!