On May 15, 2025 — sol 1,505 of its surface mission — NASA's Perseverance rover trained its Mastcam-Z camera back up the steep outer slope of Jezero Crater's rim, roughly 150 meters above the crater floor. The resulting image stretches across a sun-lit escarpment where pale-toned rocks trace a diagonal band through the frame, exposing geological layers that scientists believe have gone largely undisturbed for billions of years.
The science team has named this location the "Broom Point member" — member being the geological term for a distinct rock unit within a larger formation. Based on regional context and stratigraphic analysis, the team estimates these layered beds are at least 3.9 billion years old, placing them squarely within the Noachian period, the epoch when liquid water is thought to have shaped much of Mars's surface.
A Carefully Plotted Journey Across Jezero
Getting Perseverance to Broom Point required a methodical traverse that reflects the broader strategy NASA's Mars 2020 team has pursued since the rover's landing on February 18, 2021. After an initial survey of the crater floor, the mission shifted focus to Jezero's western delta — a sediment fan deposited where an ancient river once emptied into the crater lake. That delta has been one of the mission's primary scientific targets, given its potential to preserve biosignatures in fine-grained sedimentary rock.
From the delta, the rover then worked its way toward the crater rim, a demanding climb over terrain that challenges the vehicle's mobility systems. An orbital map released alongside the latest images traces the full route, highlighting the multiple waypoints where Perseverance paused to collect data or drill samples. Route planning relies heavily on high-resolution imagery from the Mars Reconnaissance Orbiter's HiRISE camera, which allows engineers to identify safe paths weeks in advance.
Rocks as a Record of Early Mars
The scientific stakes at Broom Point are considerable. The light-colored strata visible in the Mastcam-Z panorama are consistent with minerals that form or are altered in the presence of water — candidates include carbonates and sulfates, though precise identification awaits analysis by onboard instruments such as the SHERLOC Raman spectrometer and the PIXL X-ray fluorescence spectrometer. The layered structure itself points to a depositional environment, possibly a lakebed or a near-shore margin, where sediments accumulated gradually over geological timescales.
Any samples collected here would become part of the growing cache that Perseverance has been assembling since 2021 in anticipation of the Mars Sample Return campaign, a joint effort by NASA and the European Space Agency. That program, despite facing significant schedule and budget uncertainties, remains the intended pathway for bringing Martian rock and regolith to Earth-based laboratories equipped to conduct analyses far beyond what rover-mounted instruments can achieve.
Four Years In, the Mission Keeps Expanding Its Scope
Perseverance has now operated on Mars for more than four Earth years, well past its original primary mission window and in the company of long-lived predecessors like Opportunity. Reaching the crater rim marks a geographic milestone but, more importantly, opens a new stratigraphic chapter: the rocks exposed along Jezero's outer edge record an era of Martian history that was not accessible from the crater interior. Over the coming weeks, the science team will determine whether Broom Point warrants sample collection — a decision that could shape the scientific legacy of the entire Mars Sample Return program.
