The image provides the team a clear road map for investigating the ridgeline and the area’s ancient rock variety, including what appear to be megabreccia — large fragments (some the size of skyscrapers) hurled by a massive meteorite impact that occurred on the plain called Isidis Planitia about 3.9 billion years ago.
“What I see in this image is excellent exposure of likely the oldest rocks we are going to investigate during this mission,” said Ken Farley, Perseverance’s deputy project scientist at Caltech in Pasadena. “There is a sharp ridgeline visible in the mosaic whose jagged, angular texture contrasts starkly with the rounded boulders in the foreground. We also see a feature that may be a volcanic dike, a vertical intrusion of magma that hardened in place and was left standing as the softer surrounding material eroded away over billions of years.”
The rock color in the mosaic offers less information to the science team than the distinctive textures, which help them differentiate the rock types. Unlike Jezero Crater’s river delta, which is composed of sedimentary rock, some rocks here appear to be extrusive igneous rocks (molten rock that reached the surface as lava flows) and impactites (rocks created or modified by a meteorite impact) believed to have formed before the crater about 4 billion years ago, offering a window into the planet’s deep early crust.
New ballgame, near-marathon distance
“The rover’s study of these really ancient rocks is a whole new ballgame,” said Stack Morgan. “These rocks — especially if they’re from deep in the crust — could give us insights applicable to the entire planet, like whether there was a magma ocean on Mars and what initial conditions eventually made it a habitable planet.”
After studying Arethusa, Perseverance drove northwest to the Arbot area, where it has been analyzing other rocky outcrops. When the team is satisfied with the work accomplished there, the rover will drive south to “Gardevarri,” a site with a notably clear exposure of olivine-bearing rocks. Formed in cooling magma, these types of rocks contain information that can help scientists better understand Mars’ volcanic history and provide context for large-scale geological processes. From there, the rover is expected to head southeast toward a region the team is calling “Singing Canyon” for more insights into the planet’s early crust.
After more than five years of surface operations, Perseverance has abraded 62 rocks, collected 27 rock cores in its sample tubes (25 sealed, 2 unsealed), and traveled almost 26 miles (42 kilometers) — in other words, just shy of a marathon (26.2 miles, or 42.195 kilometers).
“Having the benefit of four previous rover missions, the Perseverance team has always known our mission was a marathon and not a sprint,” said acting Perseverance project manager Steve Lee at JPL. “We’ve almost reached marathon distance. Our selfie may show that the rover is a bit dusty, but its beauty is more than skin deep. Perseverance is in great shape as we continue our explorations and extend into ultramarathon drive distances.”
More about Perseverance
NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech, built and manages operations of the Perseverance rover on behalf of NASA’s Science Mission Directorate in Washington, as part of NASA’s Mars Exploration Program portfolio. The WATSON imaging system was built by, and is operated by, Malin Space Science Systems in San Diego.
For more information on NASA’s Perseverance, visit: