by Johnny Davila-Sandoval |
Mars rovers have thrilled scientists and the public with surprising images, a wealth of data, and intriguing hints of the possibility that the planet may have harbored life. But so far, none of them have gathered bits of the planet for study back on Earth.
An ambitious mission set to begin on Mars next year will change that, caching rocks that can be brought back to Earth for laboratory analysis—while also deploying sophisticated tools to lay the groundwork for human exploration.
Nina Lanza, a planetary geologist at Los Alamos National Laboratory (LANL), updated science journalists on the planned mission in a pre-recorded talk, released Oct. 14 as part of the Council for the Advancement of Science Writing’s New Horizons in Science briefing at ScienceWriters2020, and a live question-and-answer session during the virtual conference Oct. 19.
The newest Mars rover, expected to land Feb. 18, 2021, was named Perseverance by a high school student, Alexander Mather. Although the U.S. National Aeronautics and Space Agency (NASA) has been sending robots to Mars since the 1960s, Perseverance is different. If it is successful in its mission, it will make history as the first robot to gather Mars rocks. Lanza and other scientists are eager to analyze these rocks in the lab once a future mission can retrieve them.
Looking at rocks with a "super" cam
Lanza is part of the team that designed the SuperCam, one of the instruments of the Perseverance rover. The device will be capable of doing powerful analysis on site while Perseverance explores Mars. The SuperCam, she said, will help scientists understand more about what Mars rocks are made of, and the life forms that could have existed in the planet’s climate.
“What SuperCam does is a lot. It has two different laser-based techniques,” Lanza said. The instrument will combine two technologies for on-site analysis: laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy. While each can be informative on its own, she said, together they can provide valuable information about the chemical makeup of rocks.
Using the dual technique, SuperCam will analyze what a rock surface is made of and how the components are arranged within the rock. LIBS vaporizes a tiny amount of rock, creating a hot plasma whose colors reveal the rock’s chemical composition. Raman spectroscopy gathers information about an object’s molecular composition by measuring shifts in the energy states of laser light reflected from the rocks.
By analyzing rock surfaces using SuperCam and other on-site equipment, Lanza says, geologists will learn about their history and the possible existence of past life. And when samples are returned to Earth, LANL and other laboratories have the specialized equipment to learn more about these mysterious rocks.
Asked how scientists will know for sure that life existed on Mars, Lanza answered: “Really, what you need to do is to look for the distribution of organic presence on those rocks.” And, she added: “We look for textures that are affected, given the way we know physics operates on Earth and on Mars as well.”
Rovers have allowed scientists to explore areas that are impossible for humans, from the deep sea to other planets. Lanza concluded her CASW talk with optimism about the not-so-far-future prospect of humans visiting Mars. “Once we understand what the surface of Mars really is like and whether or not there ever was life there, we’ll be much better equipped to send humans there for a visit,” she said. “Or maybe longer.”
Johnny Davila-Sandoval (@johnnyds0411) is a PhD student at Clark University who investigates the evolution of the nervous system in annelids. He tweets about evolution, #scicomm and social awareness. He wrote this story as a participant in the ComSciCon-SciWri2020 workshop.
(Top) The Perseverance rover includes a SuperCam, which uses dual laser technologies to analyze rocks on site. (NASA image)
(Below) Planetary scientist Nina Lanza of the Los Alamos National Laboratory is part of the team designing the SuperCam instrument. (U.S. Department of Energy image)