NASA’s Perseverance fords an ancient river to reach science target

Initially regarded as little greater than a route away from rover-slowing boulders, Neretva Vallis has offered a bounty of geologic choices for the science staff.

After detouring by way of a dune subject to keep away from wheel-rattling boulders, NASA’s Perseverance Mars rover reached its newest space of scientific curiosity on June 9. The route change not solely shortened the estimated drive time to achieve that space—nicknamed “Shiny Angel”—by a number of weeks, but in addition gave the science staff a chance to search out thrilling geologic options in an historical river channel.

Perseverance is within the later phases of its fourth science marketing campaign, in search of proof of carbonate and olivine deposits within the “Margin Unit,” an space alongside the within of Jezero Crater’s rim. Positioned on the base of the northern channel wall, Shiny Angel options rocky light-toned outcrops which will characterize both historical rock uncovered by river erosion or sediments that crammed the channel. The staff hopes to search out rocks totally different from these within the carbonate-and-olivine-rich Margin Unit and collect extra clues about Jezero’s historical past.

To get to Shiny Angel, the rover drove on a ridge alongside the Neretva Vallis river channel, which billions of years in the past carried a considerable amount of the water that flowed into Jezero Crater. “We began paralleling the channel in late January and had been making fairly good progress, however then the boulders grew to become larger and extra quite a few,” mentioned Evan Graser, Perseverance’s deputy strategic route planner lead at NASA’s Jet Propulsion Laboratory in Southern California. “What had been drives averaging over 100 meters per Martian day went right down to solely tens of meters. It was irritating.”

Channel browsing

In rough terrain, Evan and his staff use rover imagery to plan drives of about 100 ft (30 meters) at a time. To go farther on any given Martian day, or sol, planners depend on Perseverance’s auto-navigation, or AutoNav, system to take over.

However because the rocks grew to become extra plentiful, AutoNav would, extra occasions than not, decide the going was to not its liking and cease, dimming the prospects of a well timed arrival at Shiny Angel. The staff held out hope, nonetheless, figuring out they may discover success reducing throughout a quarter-mile (400-meter) dune subject within the river channel.

“We had been eyeing the river channel simply to the north as we went, hoping to discover a part the place the dunes had been small and much sufficient aside for a rover to cross between—as a result of dunes have been recognized to eat Mars rovers,” mentioned Graser. “Perseverance additionally wanted an entrance ramp we might safely journey down. When the imagery confirmed each, we made a beeline for it.”

The Perseverance science staff was additionally wanting to journey by way of the traditional river channel as a result of they wished to analyze historical Martian river processes.

Rock star

With AutoNav serving to information the way in which on the channel ground, Perseverance lined the 656 ft (200 meters) to the primary science cease in a single sol. The goal: “Mount Washburn,” a hill lined with intriguing boulders, a few of a sort by no means noticed earlier than on Mars.

“The variety of textures and compositions at Mount Washburn was an thrilling discovery for the staff, as these rocks characterize a seize bag of geologic presents introduced down from the crater rim and probably past,” mentioned Brad Garczynski of Western Washington College in Bellingham, the co-lead of the present science marketing campaign. “However amongst all these totally different rocks, there was one that basically caught our consideration.” They nicknamed it “Atoko Level.”

Some 18 inches (45 centimeters) broad and 14 inches (35 centimeters) tall, the speckled, light-toned boulder stands out in a subject of darker ones. Evaluation by Perseverance’s SuperCam and Mastcam-Z devices signifies that the rock consists of the minerals pyroxene and feldspar. When it comes to the scale, form, and association of its mineral grains and crystals—and probably its chemical composition—Atoko Level it’s in a league of its personal.

Some Perseverance scientists speculate the minerals that make up Atoko Level had been produced in a subsurface physique of magma that’s presumably uncovered now on the crater rim. Others on the staff marvel if the boulder had been created far past the partitions of Jezero and transported there by the swift Martian waters eons in the past. Both manner, the staff believes that whereas Atoko is the primary of its variety they’ve seen, it will not be the final.

After leaving Mount Washburn, the rover headed 433 ft (132 meters) north to analyze the geology of “Tuff Cliff” earlier than making the four-sol, 1,985-foot (605-meter) journey to Shiny Angel. Perseverance is presently analyzing a rocky outcrop to evaluate whether or not a rock core pattern ought to be collected.