Perseverance (Mars 2020)

Perseverance is a 1,025 kg rover built to pick up rocks and leave them somewhere a later spacecraft could collect them. To reach a target worth sampling it had to land more precisely than anything before it. Jezero crater holds a fan of sediment where a river once emptied into a lake, and that fan sits among boulder fields and cliffs that would have destroyed a rover on touchdown. Two new pieces of software made the site reachable. Range Trigger fired the 21.5 m parachute based on the spacecraft's distance to its target rather than its speed, shrinking the landing ellipse to a tenth the area of Curiosity's and almost 300 times smaller than Sojourner's. Terrain-Relative Navigation, running on a downward-looking camera and a dedicated Vision Compute Element, photographed the ground rushing up between roughly 4.2 and 2.2 km altitude, matched it against a map carried onboard, fixed the spacecraft's position to about 40 m in under ten seconds, and let the descent stage move the touchdown point by up to 600 m. All of it ran alone: on 18 February 2021 Earth was 11 minutes and 22 seconds away by radio, so the seven minutes from atmospheric entry to touchdown had already happened by the time anyone heard it start. NASA named the spot Octavia E. Butler Landing, announcing it on 5 March 2021, the day after the rover's first drive of 6.5 m.

The rover carried 43 titanium tubes: 38 for samples and five sealed witness tubes that record what the sampling hardware itself was carrying from Earth. The first core, attempted on 6 August 2021, came back empty, because the rock had crumbled to powder. The tube was sealed anyway, and it stands in NASA's public table as sample 1, Roubion, an atmospheric sample, which is an accurate description of what is actually inside it. The first rock core, Montdenier, followed a month later. Over less than six weeks ending on 29 January 2023 the rover laid ten tubes on the ground about 5 to 15 m apart at a flat spot called Three Forks, a backup depot in case Perseverance could not hand its collection over itself. On 3 September 2026 NASA's published sample table showed 30 of 38 tubes filled and three of five witness tubes sealed, the newest entry a core called Gallants taken on sol 1551, 1 July 2025. Nothing later had been added to that table, so 30 is a floor rather than a count, and this page says so rather than guessing. What has not happened is the return. NASA's Mars Sample Return page still lists the campaign as a future mission, and the most recent milestone it cites is a January 2025 announcement that the agency was weighing two landing options. The tubes are sealed and waiting, most of them still aboard the rover.

Two of the seven instruments were not really about Mars's past. MOXIE, roughly the size of a car battery, drew in Martian carbon dioxide, heated it to about 800 degrees Celsius and split it into oxygen and carbon monoxide. Its first run, on sol 60, made about 5.4 grams. By the time NASA retired it after a final run on 7 August 2023 it had run sixteen times and produced 122 grams at up to 12 grams an hour and 98 percent purity or better. That is a trivial quantity beside the tens of tonnes of liquid oxygen a crew would need to launch off Mars, and it was never meant to be more than proof that the chemistry works in place. The two microphones cost far less and arguably returned more. One is an off-the-shelf part bolted to the rover's flank to record the landing; the other rides on SuperCam and listens to the instrument's own laser sparks, sampling from 20 Hz to 12.5 kHz. From those recordings an international team led by Sylvestre Maurice published the first characterisation of the Martian acoustic environment in Nature on 1 April 2022, drawn from 4 hours 40 minutes of sound gathered over the mission's first 216 sols. The result is genuinely odd. Mars has two speeds of sound: about 237.7 metres per second below 240 Hz, measured from Ingenuity's 84.43 Hz blade tone, and 246 to 257 metres per second above it. A voice on Mars would arrive out of order.

NASA publishes the traverse as a data file, and it is the most honest record of the mission there is. Downloaded on 3 September 2026, it holds 700 waypoints from sol 13 to sol 1965, a final cumulative odometry of 45,105.717 m, and exactly one panorama attached to every waypoint, which is a quiet statement about how this rover works: it does not move without looking around first. Perseverance has now driven further than Curiosity, whose equivalent file stands at 38,176.61 m after 4,998 sols. Lining the two files up date by date, Perseverance's odometer passed Curiosity's around 20 June 2025 at roughly 35.6 km, having arrived on Mars eight and a half years later. The elevation column tells the other half of the story. The rover landed at -2,569.91 m on the areoid, dropped to -2,585.87 m on sol 153, then climbed to -1,786.00 m on sol 1354, around 10 December 2024. That gain of 799.87 m matches the 800 m rim-to-crest ascent NASA quotes for the climb out of Jezero, which is a satisfying case of the raw file and the press release agreeing to within a metre. On sol 1890, 14 June 2026, the odometer passed a marathon; the Mars Reconnaissance Orbiter photographed the rover the day before. Opportunity's 45.16 km still holds the off-Earth driving record, by about 54 m in the data published on 3 September 2026, and could lose it any week.

On 21 July 2024, sol 1215, Perseverance cored a rock called Cheyava Falls in the Bright Angel formation and sealed the sample as Sapphire Canyon. The rock is marked with pale rings around dark cores that the team nicknamed leopard spots. PIXL found vivianite, a hydrated iron phosphate, and greigite, an iron sulfide, arranged in a way consistent with electron-transfer reactions between sediment and organic matter, which on Earth is a thing microbes do. Fourteen months later, on 10 September 2025, a paper led by Joel Hurowitz of Stony Brook University appeared in Nature, and NASA called the result a potential biosignature: in the agency's own definition, a substance or structure that might have a biological origin but requires more data before a conclusion can be reached. Non-biological chemistry can produce the same minerals. Settling it very probably requires the tube in a laboratory on Earth, which is the return that has no confirmed architecture. Meanwhile the rover works. It is west of Jezero now, outside the crater it landed in, and its status was checked twice on 3 September 2026: NASA's raw-image feed carried pictures taken on sol 1968, and the traverse file logged a drive on sol 1965. Since February 2026 it has been locating itself on Mars without asking Earth, running a terrain-matching algorithm on the processor it once used to talk to a helicopter that no longer flies.