Curiosity measures the severity of Mount Sharp

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NASA's Curiosity rove measured gravity on Mount Sharp in the same way that Apollo 17 astronauts measured the gravity of the Moon in 1972.

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Curiosity takes a selfie using his Mars Hand Lens lens imager at the end of his robotic arm. The images were taken on ground 2291 or January 15, 2019 at the Rock Hall drilling site on Vera Rubin Ridge. Photo credit: Credits: NASA / JPL-Caltech / MSSS

NASA Curiosity The rover, who has now left Vera Rubin Ridge, Mount Sharp, where he spent more than a year and overcame a global dust storm, measured gravity on Mount Sharp in the same way as the Apollo astronauts 17 measured the gravity of the moon. 1972.

To replicate the process used by Apollo 17 astronauts, who used a special instrument aboard the lunar vehicle they drove on the moon's surface, the mission scientists adapted the sensors used for driving. Curiosity gravimeters, which follow the changes of the gravitational attraction of an area.

The lunar rover Apollo 17. Photo credit: NASA

By measuring the gravitational pull of the rock layers of the lower part of the mountain, scientists have found that these layers are much less dense than expected.

Using accelerometers, or instruments that measure changes in the acceleration of a vehicle, and gyroscopes, rotating discs calculating the angular velocity, ie the speed to which one object revolves around another object, a team of scientists led by Kevin Lewis of Johns Hopkins University basically repeated the measurements The gravimeters of Apollo 17 were conducted in the Taurus Valley -Littrow, on the lower rocky slopes of Mount Sharp, on the Moon.

Like the Apollo 17 gravimeter, Curiosity Accelerometers studied the severity of a region each time the rover stopped moving. Scientists also incorporated engineering data collected during the first five years of the rover on Mars, which measured the gravitational tug of the planet.

Familiar with the Apollo 17 gravimeter, which took a total of 25 measurements on the lunar surface, Lewis made more than 700 measurements. Curiosity accelerometer collected between October 2012 and June 2017 and compared to computer models of the Mars gravity field and mineral density estimates produced by the rover's chemistry and mineralogy instrument, which uses an X-ray beam to determine the porosity of the rocks.

"The lower levels of Mount Sharp are surprisingly porous," said Lewis, who published his findings in the journal Science, in a NASA press release. "We know that the lower layers of the mountain have been buried over time. This compact them, making them denser. But this discovery suggests that they were not buried by as many materials as we thought. "

Image captured by Navcam from Curiosity: Left A (NAV_LEFT_A) n Sol 2306 (2019-01-31 15:01:32 UTC). Image Credit: NASA / JPL-Caltech

Located in Gale Crater, Mount Sharp is one of the highest mountains in Mars. Uncertain of mountain formation, some scientists have speculated that the crater of Gale once contained a significant amount of sediment that has eroded over time, partly because of the wind.

If the entire crater had already been filled, Mount Sharp should have many layers of fine, compact sediment. However, the data collected indicate that the lower layers of the mountain contain only one to two kilometers of this sediment.

Lewis considers that the Martian landscape is not so different from that of the Earth, although different processes have shaped the surfaces of the two planets. The landscape of the Earth was mainly water, while the landscape of Mars was shaped by wind and sand blowing, he said.

From his position in Gale Crater, Curiosity detected the beginning of the intense global dust storm that devastated the red planet in June 2018. Engine-mounted sensors on the rover's bridge measured a sudden drop in temperature during the Martian day, due to the freeze solar light by dust. This situation meant that the dust kept the night temperatures higher than usual by preventing infrared radiation from escaping into space.

With a combination of weather stations and engine readings, Curiosity successfully followed the dust storm and predicted its dissipation in mid-September.

Unlike NASA's Opportunity robot, which is powered by solar panels and remained silent in mid-June when low light prevented panels from charging its batteries, Curiosity was not affected by the dust storm because it is powered by a plutonium radioisotope thermoelectric generator.

After taking her final selfie on Vera Rubin Ridge, Curiosity He went to the summit of a rich clay ridge known as Knockfarril Hill, a winding region that he will study over the next three days Martians. After that, he will descend Knockfarril Hill and perform mobility tests to determine the best driving technique on rough terrain.

The view of Vera Rubin Ridge in January 2018. Video provided by NASA's Jet Propulsion Laboratory.

Tagged: Mars Mount Sharp Curiosity The Vera Rubin Ridge Range

Laurel Kornfeld

Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, New Jersey, who loves writing about astronomy and planetary science. She studied journalism at Douglass College at Rutgers University and earned a Graduate Certificate in Science from the Astronomy Online program at the University of Swinburne. His writings have been published online in The Atlantic, the Astronomy magazine's blog section, the British Space Conference, the 2009 IAU General Assembly Journal, The Space Reporter, and in the news bulletins of various clubs. astronomy. She is a member of Amateur Astronomers, Inc., based in Cranford, New Jersey. Specially interested in the external solar system, Laurel made a short presentation at the 2008 Global Debate held at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD.