Planned
The samples that stayed on Mars
Congress defunded Mars Sample Return in January 2026. Perseverance's sealed tubes sit in Jezero while China's Tianwen-3 aims to bring back martian rock by 2031.
sample-returnpolicymission2 min read
Humans stand on the surface of Mars
This entry has not been written. Everything below is what it has taken to get within reach of writing it — newest first, running back to the formation of the planet itself.
Date unknownWhat has to happen first
- Planned
Starship meets the one-tonne landing ceiling
Nothing heavier than Perseverance's 1,025 kg has ever been set down on Mars. Starship proposes roughly a hundred tonnes, and it has not yet reached orbit.
landingpropulsionlaunch2 min read - Planned
Rosalind Franklin finally gets a ride
Europe's drilling rover has missed three launch windows and lost its Russian lander. It now flies in October 2028 on an American rocket, for Oxia Planum in 2030.
rovermissionlaunch2 min read - Planned
The 26-month clock that governs everything
Earth and Mars line up for a cheap transfer once every 779.9 days. A six-week hardware delay does not cost six weeks; it costs more than two years.
orbitpropulsionscience2 min read
The Road Ahead
Getting people there
2027 onward, 4 milestones
Funded, in development, and not yet flown. Nothing in this era is speculation — every entry is hardware somebody is building or a constraint that is not negotiable. None of it has happened yet.
Thirteen Starship flights, and Mars slips to 2028
SpaceX has flown Starship thirteen times since April 2023. None has reached orbit, none has transferred propellant in space, and the 2026 Mars window has been given up.
propulsionlaunchhuman-spaceflight2 min read
Perseverance with the tubes it laid down at Three Forks, waiting for a ride that has not been funded. · NASA/JPL-Caltech/MSSS Mars Sample Return runs out of money
Ten sealed tubes have lain in the dust at Three Forks since January 2023, waiting for a retrieval mission that Congress declined to fund three years later.
sample-returnpolicyfailure2 min read
ESCAPADE's twin orbiters leaving Earth on New Glenn's second flight. · NASA/KSC Two small orbiters end a five-year launch drought
Nothing had left Earth for Mars since July 2020. ESCAPADE's twin orbiters broke the drought — then parked at a Lagrange point to wait a year for the transfer window.
orbiterlaunchatmosphere2 min read
The 'leopard spots' in Cheyava Falls, the texture that made the rock worth sampling. · NASA/JPL-Caltech/MSSS Leopard spots in a Martian mudstone
Perseverance drilled a rock ringed with vivianite and greigite. On Earth microbes make those minerals; on Mars nobody has yet found a plain chemical route that fits.
lifesciencerover2 min read
MOXIE installed in Perseverance before launch. · NASA/JPL-Caltech MOXIE makes oxygen out of Martian air
Perseverance carried a toaster-sized box that heated Martian carbon dioxide to 800°C and made 5.4 grams of oxygen — the first time a spacecraft manufactured a consumable on another planet.
firstsciencehuman-spaceflight2 min read
Ingenuity in flight over Jezero, photographed from the ground by Perseverance. · NASA/JPL-Caltech/ASU/MSSS Ingenuity flies, then breaks its blades on a dune
A 1.8 kg helicopter hovered three metres above Jezero for forty seconds. Seventy-two flights later, featureless sand confused its navigation camera and damaged all four blades.
helicopterfirstfailure2 min read
The first image Perseverance sent back from Jezero, minutes after touchdown. · NASA/JPL-Caltech Perseverance lands in Jezero, and we watch it happen
Five off-the-shelf cameras filmed the parachute opening and the sky crane lowering a one-tonne rover into a dry river delta. The descent microphone recorded nothing usable.
landingroverfirst2 min readChina arrives at Mars and lands a rover on its first try
Tianwen-1 entered orbit on 10 February and dropped Zhurong onto Utopia Planitia three months later — orbiter, lander and rover delivered on a country's first attempt.
orbiterroverfirst2 min readHope arrives, and the Arab world reaches another planet
The UAE had no deep-space programme six years before a 27-minute burn spent half of Hope's fuel to capture the first interplanetary mission flown by any Arab nation.
orbiterfirstatmosphere2 min read
The Present Push
Everyone goes at once
2021 – 2026, 9 milestones
Three nations arrived within a fortnight of each other. A helicopter flew in an atmosphere one percent as thick as ours, and a toaster-sized box made oxygen out of Martian air. This is the era still being written.
Mars before, and during, the 2018 planet-encircling dust storm. · NASA/JPL-Caltech/MSSS A planet-wide dust storm finishes Opportunity
A dust cloud spotted on 30 May 2018 grew to cover Mars and blacked out the sky over a rover that had driven 45 km on a 90-day warranty.
roverfailureatmosphere2 min readTwo CubeSats fly to Mars and call the landing live
MarCO-A and MarCO-B, 13.5 kilograms each, were the first CubeSats ever to leave Earth orbit — and they carried InSight's descent telemetry home live at 8 kilobits per second.
firstflybymission2 min read
SEIS under its wind and thermal shield — the first working seismometer on another planet. · NASA/JPL-Caltech InSight listens to the inside of Mars
The first seismometer set directly on another planet's surface logged 1,300 marsquakes and sized a liquid core. Its heat probe never managed to bury itself.
landersciencegeology2 min readIce cliffs expose clean water in the mid-latitudes
Eight eroding scarps at 55 to 58 degrees latitude cut open water ice more than 100 metres thick, its top just 1 to 2 metres down — and visibly banded.
watergeologyscience2 min readEurope makes orbit and loses Schiaparelli
One second of saturated gyro data convinced a lander it was already underground. It cut its parachute at 3.7 km and hit Mars at 540 km/h.
orbiterlanderfailure2 min read
Recurring slope lineae on a steep crater wall, in enhanced colour. · NASA/JPL-Caltech/Univ. of Arizona The streaks that turned back into sand
NASA announced briny water seeping down warm slopes. Two years later the same streaks were shown to stop exactly where dry sand stops, and the claim collapsed.
watergeologyscience2 min readMangalyaan reaches Mars orbit on the first try
India placed a 15-kilogram science payload in Mars orbit for about 74 million dollars, becoming the first nation to reach Mars orbit on its first attempt.
orbiterfirstmission2 min read
Artist's impression of the upper atmosphere MAVEN was built to watch leaking away. · NASA/GSFC MAVEN starts weighing the air Mars loses
The first orbiter built for the upper atmosphere measured Mars shedding roughly 100 grams of gas per second to the solar wind — and about ten times that during solar storms.
atmosphereorbiterscience2 min readCuriosity measures the radiation dose of a Mars trip
The rover's dosimeter logged 1.8 millisieverts a day in transit and 0.67 on the floor of Gale Crater — a round trip comes to roughly one sievert, two thirds past NASA's career ceiling.
human-spaceflightsciencerover2 min read
The edge of Yellowknife Bay — the mudstone that recorded an ancient freshwater lake. · NASA/JPL-Caltech Gale Crater held a lake you could have drunk from
Curiosity's first drill hole, 6.4 cm into a mudstone called John Klein, produced clay, sulfur and nitrogen — and an ancient lake of fresh, neutral water.
waterlifegeology2 min read
Curiosity's low-angle self-portrait at the Buckskin drilling site on Mount Sharp. · NASA/JPL-Caltech/MSSS Curiosity survives the seven minutes of terror
A rocket-powered crane lowered an 899-kilogram rover onto the floor of Gale Crater on cables. The system had never been flown, and it worked first time.
landingrovermission2 min read
Follow the Water
A habitable past
2012 – 2020, 11 milestones
A nuclear-powered laboratory was lowered onto Mars by a hovering crane, and within a year it had answered the question the previous fifty years had been circling: yes, this was once a place life could have lived.
Six men spend 520 days sealed in a Moscow mock-up
Mars-500 ran a Mars mission at full length with nobody leaving the building. Four of the six crew came out with a sleep or behavioural disorder.
human-spaceflightpeoplescience2 min read
Bright ice in the trench. It sublimated away between frames, which is how they knew it was water. · NASA/JPL-Caltech/University of Arizona/Texas A&M University Phoenix digs five centimetres and touches ice
Phoenix landed on rockets at 68 degrees north and scraped down to white material. It vanished in four sols — ice, not salt — and in September the lidar watched snow fall.
landerwaterlanding2 min readMars Reconnaissance Orbiter becomes the eye and the relay
The sharpest camera ever sent to another planet resolves 30 centimetres per pixel from 300 km up, and the same spacecraft relays much of what the rovers below it send home.
orbiterobservationscience2 min read
The hematite spherules Opportunity nicknamed blueberries — they form in standing water. · NASA/JPL/Cornell/USGS Spirit and Opportunity find the chemistry of water
Built for 90 sols apiece, Spirit lasted six years and Opportunity fourteen. Within eight weeks Opportunity had jarosite and hematite spherules: rock soaked in acidic water.
roverwaterlanding2 min readEurope arrives at Mars; Beagle 2 does not call home
Mars Express slid into orbit on Christmas morning. Beagle 2, released six days earlier, went silent — and was found in 2015 on the ground, partly unfolded.
orbiterlanderfailure2 min readNozomi takes five years to reach Mars, then flies past
Japan's first interplanetary probe lost the fuel to stop at Mars to a malfunctioning valve in 1998. ISAS flew it five more years anyway, then watched it coast past at 1,000 km.
orbiterfailureflyby2 min read
Odyssey’s high-energy neutron map. Blue marks hydrogen — buried water ice — close to the surface. · NASA/Jet Propulsion Laboratory/University of Arizona Odyssey counts neutrons and finds buried ice
Neutron counts fell away over both poles. Odyssey read that as ice within a metre of the surface — by one estimate enough to fill Lake Michigan twice, and a target for landers.
orbiterwaterscience2 min readTwo spacecraft lost at Mars in ten weeks
Climate Orbiter flew to 57 km altitude instead of 226 because two teams used different units. Ten weeks later Polar Lander probably shut its engines off 40 metres up.
failureorbiterlander2 min read
Gullies on a crater wall — one of Mars Global Surveyor's more argued-over discoveries. · NASA/JPL/Malin Space Science Systems Mars Global Surveyor maps the planet Mars Observer lost
Mars Observer died three days short of orbit in 1993. Its instruments were rebuilt as Global Surveyor, which found fossil crustal magnetism and geologically fresh gullies.
orbitergeologywater2 min read
Sojourner at the boulder the team named Yogi, July 1997. · NASA/JPL Pathfinder bounces onto Mars and lets Sojourner out
Airbags took the shock: the lander rebounded twelve metres, bounced at least fifteen more times across Ares Vallis, then opened to release Sojourner, 10.6 kg of rover.
roverlandingfirst2 min read
ALH84001, the Antarctic meteorite at the centre of the 1996 claim. · NASA/JSC/Stanford University A Martian meteorite is said to hold fossils
Bill Clinton stood in front of the cameras for a 1.9 kg rock from Antarctica. Within five years every line of evidence for Martian microbes had a non-biological answer.
lifegeologyscience2 min readMars's tilt turns out to be chaotic
Two 1993 calculations showed the Martian axis wanders chaotically — one integration ran it from 11 to 49 degrees over 80 million years. The present 25.19 degrees is a low value, not a constant.
scienceatmospherewater2 min readThe Soviet Union loses both Phobos probes
Phobos 1 died in September 1988 to a flawed command sequence. Phobos 2 reached Mars orbit and failed in March 1989, weeks before dropping its landers.
missionfailureorbiter2 min readTrapped gas proves a meteorite came from Mars
Gas sealed in shock glass inside a 7.9 kg Antarctic stone matched the air Viking had measured in 1976. Terrestrial laboratories suddenly held free samples of Mars.
geologyatmospherescience2 min read
The Rover Decades
Learning to land
1980 – 2011, 14 milestones
The era in which getting to Mars stopped being the hard part and landing on it started. Airbags, aeroshells, a lost orbiter that confused pounds with newtons, and two solar-powered rovers that outlived their ninety-day warranties by years.
The Viking biology results that never settled
One of Viking's three biology experiments came back positive at both landing sites. The gas chromatograph found no organic molecules at all, and the argument has never closed.
lifesciencelander2 min read
The Cydonia mesa, at the resolution and lighting that made it famous. · NASA/JPL A mesa in Cydonia looks like a face
Viking 1 orbiter frame 35A72 caught a mesa a kilometre and a half across under a low sun. The shadows read as eyes, nose and mouth, and the argument ran for 25 years.
cultureobservationorbiter2 min read
The first colour photograph ever taken from the surface of Mars, July 1976. · NASA/JPL Viking 1 and 2 land and refuse to die
Two orbiters, two landers and roughly a billion 1970s dollars. Designed for 90 days on the surface, Viking 1 kept transmitting from Chryse Planitia for over six years.
landermissionfirst2 min readNERVA runs in Nevada, then the money stops
A nuclear engine ran 28 times at Jackass Flats at twice the exhaust velocity of any chemical stage. The budget office zeroed it, and the programme ended in January 1973.
propulsionpolicyhuman-spaceflight2 min readThe Soviet 1973 armada fails four different ways
Four spacecraft launched in 19 days. Mars 4 flew past at 1,844 km, Mars 5 leaked after nine days, Mars 6 died at touchdown, and Mars 7 missed the planet by 1,300 km.
failuremissionatmosphere2 min readMars 3 lands, transmits for 20 seconds, and stops
Mars 2's lander crashed and became the first human object on the surface. Mars 3 touched down intact, sent 20 seconds of signal, and went silent for good.
landerfirstfailure2 min read
Dust covered everything when Mariner 9 arrived. Only the volcano summits showed through. · NASA/JPL Mariner 9 arrives into a planet-wide dust storm
The first spacecraft ever to orbit another planet reached Mars to find the surface hidden by dust. It waited, then mapped volcanoes, a 4,000 km canyon and dry riverbeds.
orbiterfirstgeology2 min readNixon says no to Mars
Von Braun had twelve astronauts leaving Earth orbit on 12 November 1981 aboard two nuclear ships. Seven months later Nixon put Mars behind a rigorous system of national priorities.
policyhuman-spaceflightpeople2 min read
Mars on approach, photographed by Mariner 7 in 1969. · NASA/JPL Mariner 6 and 7 find more craters
Two flybys returned 201 pictures and pinned the atmosphere at 6 to 7 millibars, but both happened to cross the oldest, dullest terrain on Mars.
flybymissiongeology2 min read
The first television picture ever returned from Mars, 15 July 1965. · NASA/JPL-Caltech/Dan Goods Mariner 4 photographs a cratered, near-airless Mars
Twenty-one grainy frames replaced the canals with craters, and a radio occultation put the surface pressure near one percent of Earth's.
flybyfirstatmosphere2 min readFive Soviet probes try for Mars and all five fail
Between 1960 and 1962 the Soviet Union launched five probes at Mars. Four never escaped Earth; the fifth, Mars 1, fell silent 106 million kilometres out.
launchfailuremission2 min read
First Contact
Machines arrive
1960 – 1979, 11 milestones
Two decades of mostly failure, punctuated by the handful of spacecraft that made it. Mariner 4 sent twenty-one photographs that killed the living Mars in a single afternoon. Viking landed anyway.
Von Braun costs out a Mars expedition
Ten ships, seventy crew, and 950 launches to assemble the fleet in Earth orbit: the first Mars expedition worked out in real numbers, and never flown.
human-spaceflightpropulsionpeople2 min readKuiper finds carbon dioxide, and no water
A lead-sulphide cell on the 82-inch at McDonald Observatory found the first molecule ever confirmed in the air of Mars: carbon dioxide. Water vapour stayed hidden until 1963.
atmospherescienceobservation2 min readAntoniadi dissolves the canals at Meudon
Four nights before opposition, the 83-centimetre Meudon refractor showed Antoniadi a Mars crowded with irregular detail and not one straight line.
observationtelescopescience2 min readBogdanov puts a communist utopia on Mars
Lenin's rival inside the Bolshevik party wrote a Mars that is already communist, running out of raw material, and debating whether to take Earth and remove the humans.
culturelifepeople2 min readWells invents the hostile Martian
Wells's Martians land near Woking, burn Surrey with a heat-ray, and die of bacteria. The invading alien enters the culture and never leaves it.
culturelife2 min readLowell builds an observatory to prove Mars is alive
A wealthy Bostonian put a telescope on a 7,200-foot ridge in Arizona to map a Martian irrigation network. The work was meticulous and entirely wrong.
observationlifepeople2 min readSchiaparelli draws the canali
Schiaparelli mapped Mars through the 1877 opposition and crossed it with fine dark lines he called canali — channels. English made them canals, and the word did the rest.
observationtelescopeculture2 min readAsaph Hall finds two moons in six nights
Mars came within 56 million kilometres in 1877. Hall had nearly given up the search when, six nights apart, he caught Deimos and then Phobos.
observationtelescopefirst2 min read
Canals and Dreamers
The Mars we invented
1877 – 1959, 8 milestones
Good observers, real telescopes, and one of the most thorough wrong answers in the history of science. The canals were never there, but the Mars they created — inhabited, dying, reachable — is the one that sent us.
The first real map of Mars, and a zero meridian
Ten years of watching through a 95 mm refractor in a Berlin garden produced the first true map of another planet — and a prime meridian Mars still uses.
telescopeobservationfirst2 min readHerschel gives Mars seasons, and inhabitants
Herschel put the tilt of Mars near 29 degrees, read the shrinking polar caps as seasons, and concluded its inhabitants probably lived much as we do.
telescopeobservationatmosphere2 min readMars gives up the size of the solar system
Observing the same Mars opposition from Paris and Cayenne gave the first sound distance to the Sun: about 140 million km, seven per cent short of the true value.
telescopeobservationscience2 min readHuygens draws a spot on Mars and clocks the day
Huygens sketched a dark triangle on Mars, watched it come back night after night, and concluded a Martian day runs about 24 hours. He was 37 minutes out.
telescopeobservationfirst2 min readEight arcminutes of Mars break the perfect circle
A stubborn eight-arcminute gap between Tycho's Mars positions and every possible circular orbit forced Kepler to the ellipse, and rebuilt astronomy around it.
orbitobservationscience2 min read
Uraniborg, Tycho Brahe's observatory on the island of Hven in the Øresund. · Wikimedia Commons Tycho Brahe builds Uraniborg and measures Mars by eye
Tycho fixed Mars to about an arcminute with sighting instruments alone, cross-checking with duplicate observers and correcting for refraction — and the logbooks went to Kepler.
observationpeoplescience2 min read
The Telescope Era
Mars gets a face
1576 – 1876, 6 milestones
Three centuries in which Mars turned from a light into a surface. It also became the specific planet whose orbit refused to be a circle, and in doing so broke two thousand years of astronomy.
Copernicus explains Mars's backwards loop
De revolutionibus turned Mars's retrograde loop into a trick of perspective — Earth overtaking it on the inside. The predictions were no better than Ptolemy's.
orbitscience2 min readIslamic astronomers take the equant apart
Al-Battani re-measured every planetary motion, Ibn al-Haytham argued the equant was physically impossible, and Ibn al-Shatir built the models Copernicus would mirror.
observationorbitscience2 min readAryabhata fixes Mars's year to within half an hour
The Aryabhatiya assigns Mars 2,296,824 orbits per 4,320,000-year cycle. Work it through with his own day count and the period is 686.9997 days; the modern value is 686.98.
orbitscience2 min read
A Roman relief of Mars in helmet and cuirass. Rome's war god handed the planet the name it still carries. · Encyclopaedia Britannica Ptolemy's equant makes Mars predictable
To fit Mars, Ptolemy let it sweep its circle at a steady rate around a point that was not the centre — a cheat that broke Greek doctrine and worked for 1,400 years.
mythologyorbitscience2 min read- c. 168 BCE
The Fire Star that Chinese astronomers could not pin down
A silk manuscript buried at Mawangdui gives working cycles for Jupiter, Saturn and Venus and none at all for Mars — the one planet that refused to keep a schedule.
observationculture2 min read - c. 652 – 60 BCE
The Tablet of Shamash, carved at Sippar in the ninth century BCE. Babylonian sky-watching was temple business first; the arithmetic came out of it sideways. · The Trustees of the British Museum Babylon turns Mars into arithmetic
Babylonian scribes logged Mars beside barley prices for six centuries, then used a 79-year repeat to predict where it would be — with no model of why.
observationscience2 min read - c. 1473 BCE
Egypt leaves Mars an empty boat
On the painted ceiling of Senenmut's tomb at Thebes, four planets ride their sacred boats and a fifth boat sails empty. The empty one is probably Mars.
observationculture2 min read
Ancient Eyes
A wandering red light
c. 1500 BCE – 1543, 7 milestones
For three thousand years Mars was a red point of light that moved strangely, and every civilisation that watched it built a story to explain the motion. Some of those stories were mythology. Some were mathematics good enough to predict where it would be.
3.7 billion years earlier
- c. 3.7 billion years ago
Olympus Mons, the largest of the Tharsis volcanoes. · NASA/JPL Tharsis rises and tips the planet over
Three hundred million cubic kilometres of magma built a bulge across a quarter of Mars, raised Olympus Mons some 22 km, and probably tipped the spin axis about 20 degrees.
geologyatmosphere2 min read - c. 3.8 billion years ago
Rivers run, and an ocean nobody can prove
Thousands of branching valleys and a delta in Jezero crater show water flowed for a long time. Whether it ever pooled into a northern ocean is still argued.
watergeology2 min read - c. 4.1 billion years ago
Artist's rendering of solar wind stripping ions from the martian upper atmosphere — the process MAVEN was built to measure. · NASA/GSFC The dynamo dies and the air starts leaving
Mars Global Surveyor found the oldest crust magnetised and the great impact basins blank — read as a dynamo dead inside the first half-billion years, though MAVEN data since has reopened the date.
atmospheregeology2 min read - c. 4.5 billion years ago
Laser altimetry of the crustal dichotomy — the northern lowlands lie several kilometres below the southern highlands. · NASA/JPL The Borealis impact splits Mars in two
The northern lowlands sit 5 km below the southern highlands. The boundary traces an ellipse 10,600 km across — plausibly the largest impact scar in the solar system.
geology2 min read - c. 4.55 billion years ago
Iron sinks and a dynamo switches on
Molten iron drained to the centre in a few million years, building a core roughly half the planet's radius — how much has been re-argued twice since 2021 — and its churning gave Mars a magnetic field.
geologyscience2 min read - c. 4.56 billion years ago
Artist's concept of the protoplanetary disc from which the rocky planets assembled. · NASA/JPL-Caltech Mars accretes fast, then stops growing
Hafnium–tungsten dating puts Mars at half its present size within two million years of the solar system's birth. Then it quit growing, at a tenth of Earth's mass.
geologyscience2 min read
Formation
A world takes shape
4.6 – 3.7 billion years ago, 6 milestones
Before anyone could look at Mars, Mars had to become the thing that would later disappoint us. It formed small, ran warm and wet for a while, then lost the magnetic field that was holding its atmosphere in place.