NASA\u2019s Perseverance Mars rover has uncovered evidence that a 245-foot-thick (75-meter-thick) stack of ancient rock on the rim of Jezero Crater was built by repeated asteroid impacts. Referred to as the \u201cBroom Point member\u201d by the rover\u2019s science team, this sequence of layered bedrock is likely more than 3.9 billion years old, making it among the oldest terrain ever examined by a Mars rover.\u00a0\u00a0<\/p>\n
Released Wednesday in the Journal of Geophysical Research: Planets<\/a>, the findings offer a window into one of the most tumultuous chapters in the history of the solar system.\u00a0\u00a0<\/p>\n \u201cSince leaving Jezero, Perseverance has been exploring a brand-new frontier, both geographically and geologically \u2014 a chapter of Martian time that predates the crater itself,\u201d said Ken Farley, Perseverance deputy project scientist at Caltech in Pasadena, California. \u201cOn Earth, our earliest geologic history has been fundamentally broken up, deformed, and erased by plate tectonics. Because Mars lacks plate tectonics to recycle its crust, this ancient record remains intact, giving us a rare glimpse into a geological time period that doesn\u2019t exist on our own planet.\u201d\u00a0<\/p>\n After ascending the western rim<\/a> of Jezero Crater in late 2024, Perseverance began examining surrounding locations<\/a> with its science instruments. Their data at Broom Point revealed six distinct rock types, including breccias \u2014 rocks composed of angular fragments \u2014 alternating with layers of fine-grained, pulverized rock dust. Rock fragments within the breccias are pocked with gas-bubble cavities, indicating they were once molten.\u00a0<\/p>\n The presence of tiny, dark, glassy beads within the layers offered an important clue about how these rocks formed. While volcanoes can produce similar glassy droplets, they rarely occur in such high abundance, pointing to asteroid impacts, instead, as the primary architect. In fact, the largest beads rival those flung out by the dinosaur-killing Chicxulub asteroid\u2019s impact on Earth.\u00a0<\/p>\n The repetition of these distinct rock types multiple times throughout this thick sequence of rock indicates that high-energy impact events happened again and again across this region of early Mars.\u00a0<\/p>\n \u201cThe different rock layers are a record of variable-sized impacts occurring at different distances from where this rock sequence was accumulating,\u201d said Alex Jones, a Ph.D. student in planetary geology at Imperial College London and lead author of the paper. \u201cSome large impacts took place very far away, some small impacts nearby. Their debris all ended up landing here, constructing this thick section of rock.\u201d\u00a0\u00a0<\/p>\n How these layers formed may suggest an interaction with water or ice. Several of the layers look like they may have been formed by fast, ground-hugging debris flows. On Earth, these powerful, fluidlike surges can occur when molten rock hits water or ice that instantly flashes into steam.\u00a0\u00a0<\/p>\n Some of Broom Point\u2019s layers tilt at angles exceeding 80 degrees \u2014 nearly vertical \u2014 which is far too steep to be caused by the impact that created Jezero Crater.\u00a0\u00a0<\/p>\n Instead, scientists suspect a cosmic \u201cone-two punch\u201d shaped this landscape long ago. First, a colossal asteroid impact created the 1,200-mile-wide (1,900-kilometer-wide) Isidis Basin, one of the largest impact basins on Mars, upending and tilting the once-flat rock layers. Later, a second asteroid likely struck, forming Jezero Crater, which measures 28 miles (45 kilometers) across. This second impact fractured and uplifted the already-tilted rocks into the dramatic formations the rover sees today.\u00a0\u00a0<\/p>\n To pin down exactly when these events took place, the Perseverance team collected two core samples, dubbed \u201cBell Island\u201d and \u201cMain River.\u201d If a future mission were to return them to Earth, laboratory dating could determine when and how often impacts were occurring on early Mars \u2014 and, by extension, the infant Earth, whose own early impact record has been erased by billions of years of plate tectonics.\u00a0<\/p>\n \u201cDuring this violent era, it wasn\u2019t rain or snow falling from the sky, but an almost constant barrage of molten rock droplets and pulverized dust kicked up by asteroid impacts,\u201d said Jones. \u201cIf we can pin down the ages of these layers, it would be like reading a cosmic weather report from 4 billion years ago.\u201d\u00a0<\/p>\n NASA\u2019s Jet Propulsion Laboratory in Southern California, which is managed for the agency by Caltech, built and manages operations of the Perseverance rover on behalf of the agency\u2019s Science Mission Directorate in Washington, as part of NASA\u2019s Mars Exploration Program portfolio. Arizona State University leads the operations of the rover\u2019s Mastcam-Z instrument, working in collaboration with Malin Space Science Systems in San Diego, on the design, fabrication, testing, and operation of the cameras. SuperCam is led by Los Alamos National Laboratory in New Mexico, where the instrument\u2019s Body Unit was developed. The rover\u2019s SHERLOC (Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals) instrument was built at NASA JPL, and its WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera was built at Malin Space Science Systems.<\/p>\n For more information on NASA\u2019s Perseverance, visit:<\/p>\n https:\/\/science.nasa.gov\/mission\/mars-2020-perseverance<\/strong><\/a><\/p>\n News Media Contacts<\/strong><\/p>\n DC Agle\u00a0 Karen Fox \/ Alana Johnson 2026-045<\/p>\n","protected":false},"excerpt":{"rendered":"NASA\u2019s Perseverance Mars rover has uncovered evidence that a 245-foot-thick (75-meter-thick) stack of ancient rock on the rim…\n","protected":false},"author":2,"featured_media":587459,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[270],"tags":[9621,18,19,17,1203,2436,8197,133,451],"class_list":["post-587458","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-asteroids","tag-eire","tag-ie","tag-ireland","tag-mars","tag-perseverance-rover","tag-planetary-science","tag-science","tag-space"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116925754620163685","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/587458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=587458"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/587458\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/587459"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=587458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=587458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=587458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov<\/a>\u00a0\u00a0<\/p>\n
NASA Headquarters, Washington
240-285-5155 \/ 202-672-4780
karen.c.fox@nasa.gov<\/a>\u00a0\/\u00a0alana.r.johnson@nasa.gov<\/a><\/p>\n