NASA’s Perseverance rover has discovered extensive macromolecular carbon within ancient river rocks in Jezero Crater, while separate mineral analyses identified chromium-bearing corundum in the crater rim. Meanwhile, NASA has proposed repurposing the rover’s engineering test model, PROMISE, for a lunar south pole mission in the early 2030s.
Macromolecular Carbon and Leopard Spots in Jezero Crater
Scientists have confirmed one of the most extensive detections yet of complex organic carbon on Mars, located inside mudstones within an ancient dried-up river channel in Jezero Crater. Published in Science Advances, the findings rely on hundreds of detections of macromolecular carbon—tangled networks of large carbon molecules—discovered inside two rocks sampled by NASA’s Perseverance rover. These samples belong to the Bright Angel formation within Neretva Vallis, a channel that previously fed a lake inside the crater.
Using the SHERLOC instrument, which employs an ultraviolet laser and fluorescence spectroscopy, the research team identified complex carbon in sedimentary minerals as well as later-forming carbonate and sulphate minerals. This dual presence indicates that carbon was integrated into the rock across at least two distinct historical phases: during initial sediment deposition and later groundwater alteration. While organic molecules serve as life’s fundamental building blocks, the observations cannot confirm whether the molecules arose from biological or non-biological mechanisms such as meteorite delivery or hydrothermal reactions.
This organic discovery builds on earlier excitement from 2024 when Perseverance identified distinctive ‘leopard spots’ on rocks at the same site, specifically a rock nicknamed Cheyava Falls. On Earth, similar millimetre-sized spots can form through chemical and mineral reactions tied to microbial activity, though non-biological explanations remain viable. Astrobiologists note that while terrestrial geologists would immediately attribute such markers to life, the opposite approach applies on Mars, where every alternative must be systematically ruled out.
Gemstone Signatures in Martian Float Rocks
Beyond organic carbon, Perseverance uncovered an entirely different geological surprise. When the rover zapped pale rocks across Jezero Crater with its laser, the rocks contained a mineral never before found on Mars: corundum, the crystalline material that forms rubies and sapphires. Analysis also revealed traces of chromium, the element responsible for the reddish-pinkish hues of rubies.
wrote a team led by Ollila in a conference abstract, noting that SuperCam’s TRL analysis of three plagioclase-rich float rocks in the crater rim were found to exhibit clear signatures of chromium-bearing corundum. The researchers subsequently published their full analysis in Geophysical Research Letters. Corundum formation typically requires conditions enriched in aluminum and depleted in silicon at high temperatures or via tectonic processes, making its detection in plagioclase-dominated Martian rocks exceptionally puzzling because silicate minerals normally consume available aluminum.
The three float rocks—named Hampden River, Coffee Cove, and Smiths Harbour—were unattached to local bedrock, suggesting transport from elsewhere. Between March and July 2025, Perseverance analyzed the samples using time-resolved luminescence spectroscopy. Laboratory comparisons against terrestrial ruby, sapphire, and diaspore revealed matching luminescence peaks at 692.7 and 694.1 nanometers, with the Smiths Harbour sample exhibiting a lingering glow lasting about 3 milliseconds, squarely matching terrestrial corundum. Researchers favor the hypothesis that the colossal impact carving Jezero Crater billions of years ago generated the extreme heat and pressure necessary to forge these metamorphic minerals.
Repurposing a Rover Test Model for the Lunar South Pole
While Perseverance unearths clues on Mars, its earthly counterpart is slated for a career change. NASA has announced a proposal to send a rover called PROMISE, which is short for Polar Rover for Observation, Mapping and In-Situ Exploration, to the lunar surface.
Originally known as OPTIMISM—short for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars—the test model is being redesigned as a hybrid incorporating elements of both the Perseverance and Curiosity engineering versions. NASA administrator Jared Isaacman noted during an agency moon base update that We've had years now of experience operating the two rovers on the surface of Mars, and we've got this hardware that the taxpayers have invested a lot in.
PROMISE is intended to scout the lunar south pole to characterize the surface and subsurface near abundant water ice reserves. To operate without sunlight, the rover will feature a multi-mission radioisotope thermoelectric generator utilizing plutonium. Program manager Carlos García-Galán emphasized that For moon-based objectives, having a nuclear RTG on it allows us to go anywhere we want, regardless of the illumination,
adding that Surviving the lunar night is going to be one of the bigger challenges with this capability; we wouldn't have to worry about that.
Despite its potential, PROMISE remains a conceptual vehicle requiring extensive upgrades, including flight-ready scientific instruments, thermal sensors, communications gear, a generator, and hardening against abrasive lunar dust. The Planetary Society estimates the mission will cost between $700 million and $1.3 billion, with a targeted launch timeframe in the early 2030s.
