Study determines the original orientations of rocks drilled on Mars

Because it trundles round an historic lakebed on Mars, NASA’s Perseverance rover is assembling a one-of-a-kind rock assortment. The car-sized explorer is methodically drilling into the Crimson Planet’s floor and pulling out cores of bedrock that it is storing in sturdy titanium tubes. Scientists hope to at least one day return the tubes to Earth and analyze their contents for traces of embedded microbial life.

Because it touched down on the floor of Mars in 2021, the rover has stuffed 20 of its 43 tubes with cores of bedrock. Now, MIT geologists have remotely decided an important property of the rocks collected up to now, which is able to assist scientists reply key questions concerning the planet’s previous.

In a study printed right now (March 4) within the journal Earth and Area Science, an MIT workforce stories that they’ve decided the unique orientation of most bedrock samples collected by the rover up to now. By utilizing the rover’s personal engineering information, such because the positioning of the automobile and its drill, the scientists may estimate the orientation of every pattern of bedrock earlier than it was drilled out from the Martian floor.

The outcomes signify the primary time scientists have oriented samples of bedrock on one other planet. The workforce’s technique might be utilized to future samples that the rover collects because it expands its exploration exterior the traditional basin. Piecing collectively the orientations of a number of rocks at numerous places can then give scientists clues to the situations on Mars through which the rocks initially shaped.

“There are such a lot of science questions that depend on with the ability to know the orientation of the samples we’re bringing again from Mars,” says research creator Elias Mansbach, a graduate scholar in MIT’s Division of Earth, Atmospheric and Planetary Sciences.

“The orientation of rocks can let you know one thing about any magnetic field that will have existed on the planet,” provides Benjamin Weiss, professor of planetary sciences at MIT. “It’s also possible to research how water and lava flowed on the planet, the path of the traditional wind, and tectonic processes, like what was uplifted and what sunk. So it is a dream to have the ability to orient bedrock on one other planet, as a result of it will open up so many scientific investigations.”

Weiss and Mansbach’s co-authors are Tanja Bosak and Jennifer Fentress at MIT, together with collaborators at a number of establishments together with the Jet Propulsion Laboratory at Caltech.

Profound shift

The Perseverance rover, nicknamed “Percy,” is exploring the ground of Jezero Crater, a big affect crater layered with igneous rocks, which can have been deposited from previous volcanic eruptions, in addition to sedimentary rocks that seemingly shaped from long-dried-out rivers that fed into the basin.

“Mars was as soon as heat and moist, and there is a risk there was life there at one time,” Weiss says. “It is now chilly and dry, and one thing profound will need to have occurred on the planet.”

Many scientists, together with Weiss, suspect that Mars, like Earth, as soon as harbored a magnetic subject that shielded the planet from the sun’s solar wind. Situations then might have been favorable for water and life, not less than for a time.

“As soon as that magnetic subject went away, the sun’s solar wind—this plasma that boils off the sun and strikes quicker than the velocity of sound—simply slammed into Mars’ ambiance and will have eliminated it over billions of years,” Weiss says. “We need to know what occurred, and why.”

The rocks beneath the Martian floor seemingly maintain a report of the planet’s historic magnetic subject. When rocks first type on a planet’s floor, the path of their magnetic minerals is ready by the encircling magnetic subject. The orientation of rocks can thus assist to retrace the path and depth of the planet’s magnetic subject and the way it modified over time.

Because the Perseverance rover was gathering samples of bedrock, together with floor soil and air, as a part of its exploratory mission, Weiss, who’s a member of the rover’s science workforce, and Mansbach appeared for methods to find out the unique orientation of the rover’s bedrock samples as a primary step towards reconstructing Mars’ magnetic historical past.

“It was an incredible alternative, however initially there was no mission requirement to orient bedrock,” Mansbach notes.

Roll with it

Over a number of months, Mansbach and Weiss met with NASA engineers to hash out a plan for how you can estimate the unique orientation of every pattern of bedrock earlier than it was drilled out of the bottom. The issue was a bit like predicting what path a small circle of sheetcake is pointing, earlier than twisting a spherical cookie cutter in to tug out a bit. Equally, to pattern bedrock, Perseverance corkscrews a tube-shaped drill into the bottom at a perpendicular angle, then pulls the drill straight again out, together with any rock that it penetrates.

To estimate the orientation of the rock earlier than it was drilled out of the bottom, the workforce realized they should measure three angles, the hade, azimuth, and roll, that are just like the pitch, yaw, and roll of a ship. The hade is actually the lean of the pattern, whereas the azimuth is absolutely the path the pattern is pointing relative to true north. The roll refers to how a lot a pattern should flip earlier than returning to its unique place.

In speaking with engineers at NASA, the MIT geologists discovered that the three angles they required have been associated to measurements that the rover takes by itself in the middle of its regular operations. They realized that to estimate a pattern’s hade and azimuth they may use the rover’s measurements of the drill’s orientation, as they may assume the lean of the drill is parallel to any pattern that it extracts.

To estimate a pattern’s roll, the workforce took benefit of one of many rover’s onboard cameras, which snaps a picture of the floor the place the drill is about to pattern. They reasoned that they may use any distinguishing options on the floor picture to find out how a lot the pattern must flip with the intention to return to its unique orientation.

In circumstances the place the floor bore no distinguishing options, the workforce used the rover’s onboard laser to make a mark within the rock, within the form of the letter “L,” earlier than drilling out a pattern—a transfer that was jokingly referred to on the time as the primary graffiti on one other planet.

By combining all of the rover’s positioning, orienting, and imaging information, the workforce estimated the unique orientations of all 20 of the Martian bedrock samples collected up to now, with a precision that’s akin to orienting rocks on Earth.

“We all know the orientations to inside 2.7 levels uncertainty, which is best than what we will do with rocks within the Earth,” Mansbach says. “We’re working with engineers now to automate this orienting course of in order that it may be achieved with different samples sooner or later.”

“The following phase would be the most enjoyable,” Weiss says. “The rover will drive exterior the crater to get the oldest identified rocks on Mars, and it is an unimaginable alternative to have the ability to orient these rocks, and hopefully uncover plenty of these historic processes.”

This story is republished courtesy of MIT Information (web.mit.edu/newsoffice/), a well-liked web site that covers information about MIT analysis, innovation and educating.