Numinous / Thread
Who Gets to Look
Who has been allowed to do this work, and who got the credit?
The history of astronomy is also a history of access: which people were admitted to the telescope, whose names went on the papers, and who is invited to look up at all.
How it runs
The Harvard computers were paid to measure plates, not to theorise, and two of them found the period-luminosity relation and the composition of stars anyway.
Formal barriers were explicit and recent. Graduate programmes and observatories excluded women by policy well into living memory, which shaped who could build a career.
Credit followed the same pattern. Discoveries were published under a supervisor's name, and prizes went elsewhere, in cases the field now acknowledges openly.
Access is also physical. Dark skies are disappearing under light pollution, and most people alive have never seen the Milky Way from where they live.
The counterweight is participation: amateur observers, citizen science projects and public data archives now contribute real results rather than decoration.
The entries
In the order they enter the story. Each opens its full entry in the wiki.
Henrietta Swan Leavitt
Henrietta Swan Leavitt found that a Cepheid variable's pulse rate gives away its true brightness. That is the first standard candle, and the rung every measured distance beyond our galaxy rests on.
Cecilia Payne-Gaposchkin
Cecilia Payne-Gaposchkin worked out from stellar spectra that stars are almost entirely hydrogen and helium, then published the result with a disclaimer calling it not real, because a senior colleague told her to.
Planetariums and Science Museums
The buildings where most people meet astronomy in person: a dome that puts an accurate sky indoors, a hall that holds the hardware, and a public eyepiece pointed at the real thing.
Nancy Grace Roman
NASA's first Chief of Astronomy and its first woman executive, who built the constituency and the political case for putting large telescopes above the atmosphere.
Vera Rubin
Vera Rubin discovered that the universe is mostly invisible. Her rotation curves showed that every spiral galaxy sits inside a halo of matter that pulls on things but does not shine.
Jocelyn Bell Burnell
Jocelyn Bell Burnell found a quarter inch of scruff on a chart recorder in 1967 and refused to file it as interference. It was the first pulsar. The 1974 Nobel Prize went to her supervisor.
Neil deGrasse Tyson
Neil deGrasse Tyson runs the Hayden Planetarium and has kept astrophysics in the mainstream conversation for two decades, as a working astrophysicist whose main output is public rather than published.
Andrea Ghez
Andrea Ghez shared the 2020 Nobel Prize in Physics for proving that a supermassive black hole sits at the center of the Milky Way, by watching individual stars orbit it for two decades.
Data Science in Astronomy
Astronomy has always been a data science. What changed is the scale: surveys now produce far more than anyone can look at, so calibration, classification and discovery are increasingly automated.
SpaceX
The launch company that made orbital rocket stages reusable, and now flies more mass to orbit than everyone else combined. For astronomy it is both the ride to space and the brightest thing in the way.
Citizen Science in Astronomy
Volunteers classifying survey data at scale. Galaxy Zoo showed that a crowd could sort a million galaxies, and the method now covers transits, detector glitches and brown dwarfs.
Planet Labs
The company that photographs every land surface on Earth every day, using hundreds of small, short-lived satellites instead of a few exquisite ones. Its argument about cadence over depth now shapes astronomical surveys too.
Amateur Astronomy
Astronomy done without professional pay. Amateurs still supply variable star photometry, asteroid occultation timings and transit measurements that professional programmes depend on.
Astronomy in Culture
How astronomy reaches everyone who never looks through a telescope: science fiction, cinema, television, podcasts, and the philosophical arguments each new displacement forces.
Dark Sky Preservation
The work of keeping the night dark: shielded fixtures, warm-spectrum lamps, lighting ordinances and certified places, against skyglow that now hides the Milky Way from more than a third of humanity.
Ethics and Policy
The rules for space, and the widening gap between them and what is now technically possible: a 1967 treaty, voluntary debris guidelines, contested resource claims, and no regulator at all for the brightness of a satellite.
Introduction to Astronomy
The oldest science, and the one anybody can start by looking up. What the field covers now, the instruments it is built on, and the questions it has turned from philosophy into funded research.
Public Engagement Overview
Astronomy is the science you can start doing by looking up. Planetariums, citizen science, amateur clubs and dark sky campaigns are the infrastructure that keeps it that way.
Timeline
Copernicus moves the Earth
De revolutionibus put the Sun at the centre. The model was not obviously more accurate than Ptolemy's at first, but it made the planets' retrograde loops a consequence of geometry rather than a mechanism bolted on.
A telescope is pointed at the sky
Galileo published mountains on the Moon, four satellites of Jupiter and the phases of Venus. The heavens turned out to contain objects with surfaces and orbits rather than perfect spheres.
The War of the Worlds sets the template
H.G. Wells took the supposed Martian canals, which turned out not to exist, and built the first modern alien contact narrative on them. Every invasion story since is a reply to it.
Hired as a computer at Harvard College Observatory
After years as a volunteer assistant, Leavitt was put on Edward Pickering's staff to measure and catalog stellar brightness from glass plates. The women were paid roughly half what male assistants earned.
A note about the brighter ones
Working through plates of the Magellanic Clouds taken from Harvard's Peru station, Leavitt published a brief observation: among the Cepheids, the brighter stars had the longer periods.
The AAVSO is founded
A network of amateurs begins reporting variable star brightness estimates on a common standard. The resulting database now holds tens of millions of measurements and decades-long light curves no single observatory could have assembled.
The period-luminosity relation
Twenty-five Cepheids in the Small Magellanic Cloud, all at roughly the same distance, fell on a straight line when period was plotted against magnitude. Four pages. The paper went out under Pickering's name.
Calibration, and the size of the Milky Way
Hertzsprung and then Shapley tied the relation to an absolute scale using statistical parallax. Shapley used it on globular clusters and found the Sun is nowhere near the center.
An Eddington lecture at Cambridge
Payne heard Arthur Eddington describe the eclipse expedition that had just confirmed general relativity. She wrote later that it gripped her so completely she could not sleep, and she switched to astronomy.
Springfield Telescope Makers form in Vermont
Russell Porter runs a telescope-making class in Springfield, Vermont. The group that came out of it built the Breezy Hill clubhouse and started the Stellafane convention, the longest-running amateur astronomy gathering in the United States.
Death, and a Nobel nomination that arrived too late
Leavitt died of cancer at 53. Gosta Mittag-Leffler wrote in 1924 intending to nominate her, and was told she was gone. The prize is not awarded posthumously.
Cambridge to Harvard
Cambridge gave women certificates rather than degrees until 1948, and Britain offered no professional route for a woman astronomer. Payne took a fellowship to Harlow Shapley's new graduate program instead.
The Zeiss projector puts stars indoors
Walther Bauersfeld's Model I was demonstrated in Munich, throwing roughly 4,500 stars onto a hemispherical dome with correct relative brightness and position, and simulating the sky's rotation at any latitude.
The planetarium is invented
Zeiss demonstrated a projector in Munich that put an accurate sky on a dome. City audiences who had never seen the Milky Way through the smoke could suddenly see it indoors.
Stellar Atmospheres, and a retraction she did not believe
Applying the Saha ionization equation to hundreds of spectra, Payne found hydrogen roughly a million times more abundant in stars than on Earth. Henry Norris Russell called it clearly impossible, and she printed his objection as her own caveat.
The first permanent planetarium opens
The Deutsches Museum installed the Zeiss system as a fixed exhibit. Audiences in a coal-smoke city saw a Milky Way most of them had never seen from their own street.
Russell reaches the same conclusion
Working the problem independently, Russell published that stars are predominantly hydrogen and credited Payne's priority. The discovery was attributed to him anyway for decades.
The universe is found to be expanding
Edwin Hubble measured distances and recession velocities for a set of galaxies and found the two proportional. Cosmology stopped being a branch of philosophy and became a measurement.
Adler opens in Chicago
The first planetarium in the Western Hemisphere, founded by businessman Max Adler on the advice of the Deutsches Museum's director. It became a collecting institution for historic astronomical instruments as well as a theatre.
A working partnership on variable stars
Payne married the Russian-born astronomer Sergei Gaposchkin. Their systematic catalogs of variables in the Milky Way and the Magellanic Clouds ran for decades.
Griffith Observatory opens free to the public
Griffith J. Griffith's bequest specified that looking through the telescope should cost nothing. The observatory has run public viewing on the slope of Mount Hollywood every clear night since.
The Hayden Planetarium opens in New York
Housed at the American Museum of Natural History, it became the public face of astronomy in the largest city in the United States under a run of directors from Clyde Fisher to Neil deGrasse Tyson.
Starts an astronomy club at eleven
Living in Reno, Nevada, under a dark sky at the edge of town, Roman organized a club with her classmates and worked through a book on constellations and celestial objects. She never lost the interest, despite two decades of adults telling her that science was not for girls.
Vassar, and a door closed at Princeton
Rubin graduated as the only astronomy major in her class and applied to Princeton, which did not admit women to its astronomy graduate program and would not until 1975. She went to Cornell.
Doctorate from the University of Chicago
After a bachelor's degree in astronomy from Swarthmore in 1946, earned at the college's Sproul Observatory, she took her PhD at Chicago, whose graduate astronomy program ran out of Yerkes Observatory in Williams Bay, Wisconsin. She stayed on at Yerkes for six more years.
Links stellar chemistry to stellar motion
Handed the sun-like F5 to G5 stars nobody else wanted, Roman found that those with weaker lines from elements heavier than helium had a far wider spread of velocities and sat further off the plane of the Milky Way. Chemistry records when a star formed; orbit records where. Published in the Astrophysical Journal, received 22 July 1950.
The changed spectrum of AG Draconis
Observing at McDonald Observatory in September 1952, Roman found that the tenth-magnitude object BD+67 922, now known as AG Draconis, had changed almost beyond recognition since the 1940s: an emission continuum swamping all but the heaviest absorption lines. The note raised her profile in the field.
Doctorate at Georgetown under George Gamow
Her thesis showed that galaxies are not scattered at random but clumped into large-scale structures. Galaxy clustering would not be widely accepted for another twenty years.
Leaves Yerkes for the Naval Research Laboratory
Told plainly that a woman had no path to tenure, she took a job in the new field of radio astronomy at NRL, mapped the galaxy at 67 centimeters, and rose to head the microwave spectroscopy section. Four years in an engineering shop taught her how flight projects are actually built.
Full professor, thirty-one years late
Payne-Gaposchkin became the first woman promoted to full professor in Harvard's Faculty of Arts and Sciences, and the first to chair a Harvard department. Her courses had not appeared in the catalog for years.
NASA's first Chief of Astronomy
Approached after a lecture by Harold Urey and asked whether she knew anyone who might build a space astronomy program, she applied herself. She joined six months after the agency opened, becoming its first Chief of Astronomy and the first woman to hold an executive position at NASA. Taking the job ended her own research.
The Orbiting Solar Observatories begin flying
John Lindsay's spinning-wheel design pointed two instrument boxes at the Sun, the easiest target in the sky to lock onto, so the OSOs flew years ahead of the harder pointed telescopes. Eight launched between March 1962 and June 1975, covering a full eleven-year solar cycle.
The Big Bang leaves a fingerprint
Penzias and Wilson found a microwave hiss coming equally from every direction. It was the cooled remnant of the hot early universe, and it settled the argument with the steady state model.
Building the Interplanetary Scintillation Array
Bell spent her first two Cambridge years hammering posts and stringing cable across four and a half acres of field, wiring over a thousand dipoles into a telescope meant to study quasars.
Orbiting Astronomical Observatories, two of four
Four experiments proposed during the International Geophysical Year were flown on a common spacecraft that had to point accurately anywhere in the sky. Four OAOs launched between 1966 and 1972 and only two worked, which was a poor procurement record and a decisive proof that a pointed telescope in orbit could do real astronomy.
The Outer Space Treaty opens for signature
Opened on 27 January 1967 and in force from October, the treaty bars national appropriation of celestial bodies, requires peaceful use, and makes states answerable for what their private companies do. More than a hundred states are party to it.
A pulse every 1.337 seconds
Examined at higher time resolution, the scruff resolved into pulses more regular than most terrestrial clocks. The team labelled the source LGM-1, for Little Green Men, and did not mean it.
2001: A Space Odyssey gets the vacuum right
Silent space, Newtonian mechanics, centrifugal gravity, no swooping fighter craft. Kubrick and Clarke established a standard of physical realism that later space cinema is still measured against.
Published in Nature
Three more sources in different parts of the sky killed the artificial hypothesis. Hewish was listed first author and Bell second. Thomas Gold identified the objects as rotating neutron stars.
Andromeda does not slow down
With Kent Ford, Rubin measured how fast stars orbit at different radii in M31 and found the curve flat. Stars at the edge move as fast as stars near the middle, which Newtonian gravity forbids.
The Nobel Prize, without her
Antony Hewish was cited for his decisive role in the discovery of pulsars, alongside Martin Ryle for aperture synthesis. Fred Hoyle attacked the omission publicly, and it is still the canonical case in physics.
Kessler describes the collision cascade
Donald Kessler argued that above a certain debris density, collisions generate debris faster than it decays, and the cascade makes an orbital band unusable. The mechanism is now the standard argument for deorbit rules.
The Moon Agreement fails
It declared lunar resources the common heritage of mankind and proposed an international regime to license extraction. Every major spacefaring nation refused to sign. Fewer than twenty countries are party, none of them with a significant space programme.
Retires from NASA
She left during an early-out window, partly to care for her mother. Edward Weiler, her successor as Chief of Astronomy, coined the phrase "mother of Hubble." She then worked half-time for nearly two more decades, ending up effectively running the science side of Goddard's Astronomical Data Center.
Cosmos: A Personal Voyage airs
Thirteen episodes on the history of astronomy, stellar physics, the search for life and the fragility of Earth. It reached an audience in the hundreds of millions and is the reason a generation of astronomers chose the field.
Cosmos reaches a general audience
Carl Sagan's thirteen-part series treated the audience as capable of the real argument rather than the simplified one. Its viewership ran into the hundreds of millions.
The pattern holds, galaxy after galaxy
Flat rotation curves turned up in spiral after spiral, across sizes, types and luminosities. Each one implies a halo outweighing its visible matter by a factor of five to ten.
Elected to the National Academy of Sciences
Only the second woman astronomer so elected. She then spent years pushing for more, and mentoring the women the field had made room for late.
Contact turns SETI into a novel
Sagan used the search for extraterrestrial intelligence to argue about evidence and faith rather than about aliens. The 1997 film kept the argument intact.
An amateur co-discovers SN 1987A
Albert Jones, observing from Nelson, New Zealand, independently spotted the supernova in the Large Magellanic Cloud within hours of the professional discovery at Las Campanas. It was the closest supernova seen since 1604.
The International Dark-Sky Association is founded
Set up in Tucson by the astronomer David Crawford and the physician Tim Hunter, close to the observatories the city's lighting codes were written to protect. The board voted to rename it DarkSky International in 2022 and announced the change on 1 June 2023.
The dark sky movement organises
The International Dark-Sky Association was founded to certify dark sky places and push lighting ordinances. Light pollution was reframed as an environmental and health problem, not only an astronomical inconvenience.
Voyager 1 takes the Pale Blue Dot
At Sagan's urging, the spacecraft turned back from beyond Neptune and photographed Earth as a fraction of a pixel. It has done more argumentative work than any other image astronomy has produced.
Doctorate at Columbia
Tyson's research covered the structure of the Milky Way's galactic bulge and the chemical abundances of dwarf stars, after a bachelor's at Harvard and a master's at Texas.
Doctorate at Caltech
Ghez worked under Gerry Neugebauer on high-resolution infrared observations of young stellar objects, learning to see through the dust that hides most of the galaxy.
To UCLA, and the galactic center
She joined the faculty at twenty-nine and started tracking stars near Sagittarius A*, in direct competition with Reinhard Genzel's group using the VLT in Chile.
Thomas Bopp co-discovers a great comet
An amateur observing with borrowed equipment in Arizona and a professional in New Mexico found the same object on the same night. Comet Hale-Bopp stayed visible to the naked eye for roughly eighteen months.
The first planet around a Sun-like star
Mayor and Queloz announced 51 Pegasi b, a gas giant orbiting its star in four days. Nothing in the solar system had prepared anyone for it, and the field of exoplanets started that week.
Director of the Hayden Planetarium
He became the Frederick P. Rose Director at the American Museum of Natural History, the planetarium he had first visited at the age of nine, and has held the post since.
SDSS makes a survey into a database
The Sloan Digital Sky Survey started operations and eventually catalogued photometry for over 500 million objects and spectra for more than five million, queryable by anyone.
The Rose Center, and the Pluto problem
The rebuilt planetarium reopened with Pluto exhibited among the Kuiper Belt objects rather than the planets. The International Astronomical Union reached the same conclusion six years later.
The Rose Center rebuilds the Hayden
The old dome was replaced by a sphere inside a glass cube, with a digital projection system able to render three-dimensional flights through survey data rather than a fixed star field.
Flagstaff becomes the first Dark Sky City
Flagstaff, Arizona, was recognised in 2001 for its outdoor lighting policy and fixture retrofits, done to protect Lowell Observatory. The International Dark Sky Places programme was created to give other towns the same incentive.
President of the Royal Astronomical Society
She later led the Institute of Physics from 2008, and became the first woman to preside over the Royal Society of Edinburgh in 2014.
A volunteer finds Hanny's Voorwerp
Dutch schoolteacher Hanny van Arkel flagged a strange green blob beside the galaxy IC 2497. It turned out to be gas still lit by a quasar that had already switched off, an ionisation echo nobody had catalogued.
China destroys a satellite with a missile
The anti-satellite test on 11 January 2007 broke up a defunct weather satellite and left over 3,500 trackable fragments, many in orbits that will persist for decades. It remains the single worst debris-generating event.
Galaxy Zoo opens for classifications
Kevin Schawinski needed morphologies for roughly a million Sloan Digital Sky Survey galaxies and no algorithm of the day could supply them. Within a day the site was taking tens of thousands of classifications an hour.
Crowdsourcing gets a million galaxies classified
Galaxy Zoo showed that the bottleneck in survey science was human throughput, not human ability. It also produced the labels that trained the classifiers which replaced it.
Galaxy Zoo turns viewers into contributors
Volunteers were asked to classify a million Sloan galaxies by shape. The site took tens of thousands of classifications an hour on its first day and the resulting catalogue is still cited.
Falcon 1 reaches orbit on the fourth try
After failures in 2006, 2007 and early 2008, the fourth Falcon 1 made orbit on 28 September 2008. It was the first privately funded liquid-fuelled rocket to do so. The company was close to running out of money, and a fourth failure would probably have ended it.
StarTalk begins
The podcast puts comedians, athletes and musicians in the room with scientists, and has done more to normalize astrophysics as small talk than any documentary.
Iridium 33 and Cosmos 2251 collide
The first accidental collision between two intact satellites happened on 10 February 2009 and produced more than 2,000 trackable fragments. Neither operator had manoeuvred, and nobody was responsible for making them.
A backyard telescope finds a scar on Jupiter
Anthony Wesley, observing from Australia on 19 July, spotted a dark impact feature in Jupiter's southern hemisphere. NASA turned Hubble's newly installed Wide Field Camera 3 on it four days later.
The Green Peas get a paper
Volunteers kept setting aside small round green objects the classification tree had no box for. The resulting paper described a class of compact, extremely star-forming galaxies that resemble conditions in the early universe.
Three NASA Ames scientists invert the design
Will Marshall, Robbie Schingler and Chris Boshuizen argued that users wanted frequency more than resolution. Instead of one exquisite satellite lasting fifteen years, build hundreds of cheap ones lasting three to five and replace them continuously.
Dark Universe ships to hundreds of domes
The American Museum of Natural History production visualised dark matter structure from a cosmological simulation. Fulldome shows had become a distribution format, not a one-building exhibit.
Interstellar renders a black hole from the equations
Kip Thorne supplied the general relativistic equations and the visual effects team ray-traced them rather than approximating. The renderer produced a peer-reviewed paper on lensing by spinning black holes.
Cosmos: A Spacetime Odyssey
The sequel to Sagan's series, produced by Ann Druyan and Seth MacFarlane, aired on Fox and National Geographic and won four Emmy Awards.
The Martian makes orbital mechanics a plot device
A survival story driven by real chemistry, botany and transfer orbits, shot against actual HiRISE terrain. NASA used the release as an outreach hook rather than issuing corrections.
Buying a constellation instead of building one
The BlackBridge acquisition added five RapidEye satellites to 87 Doves already in orbit. Buying capability rather than developing it became a pattern, most visibly with Google's SkySats two years later.
Gravitational waves are detected
LIGO recorded the merger of two black holes as a strain of one part in 10^21 across four-kilometre arms. Astronomy acquired a channel that does not involve light.
The US legislates asteroid resource ownership
The Commercial Space Launch Competitiveness Act, signed on 25 November 2015, asserts that a US company owns what it extracts from a celestial body even though nobody may own the body. Luxembourg passed a comparable law in 2017.
A Falcon 9 booster lands after delivering a payload
On 21 December 2015 the first stage returned to a pad at Cape Canaveral, the first propulsive landing of an orbital-class booster after a real mission. The first drone ship landing followed in April 2016, after several that ended in explosions.
An atlas measures what has been lost
A world atlas of artificial night sky brightness put numbers on it: most of the population lives under light-polluted skies and roughly a third cannot see the Milky Way from where they live.
The world atlas of artificial night sky brightness
Falchi and colleagues modelled skyglow globally from satellite radiance and ground measurements. More than 80 per cent of the world's population, and over 99 per cent of Americans and Europeans, live under light-polluted skies. The Milky Way is hidden from over a third of humanity.
Gravity Spy brings volunteers into LIGO
The project paired citizen classification with machine learning on Advanced LIGO detector artefacts. Volunteers went on to name glitch categories the detector engineers had not separated out themselves.
Humans and machines split the work
Gravity Spy paired volunteer classification of LIGO detector glitches with machine learning. The model handled the bulk; the people handled the cases it had no category for.
Death, and no Nobel Prize
Rubin died at eighty-eight. Her evidence for dark matter ranks with the expanding universe and the microwave background, both of which were recognized in Stockholm.
Astrophysics for People in a Hurry
A short book of chapter-length answers spent over a year on the New York Times bestseller list, which is not what happens to cosmology primers.
Backyard Worlds starts hunting brown dwarfs
Volunteers scan time-series WISE infrared images for objects that move between frames. The project has turned up hundreds of brown dwarfs, including some of the coldest substellar objects known.
88 Doves ride a single rocket
The Indian PSLV flight that set the record of 104 satellites on 15 February 2017 was mostly Planet's. The same year Google sold Terra Bella and its sub-metre SkySat constellation to the company.
S0-2 rounds the black hole
The star passed within roughly 120 AU at over 7,600 km/s, watched in real time by both groups. Its light showed the gravitational redshift general relativity predicts and Newtonian gravity does not.
The Special Breakthrough Prize, given away
Bell Burnell received three million dollars and donated all of it to the Institute of Physics, to fund graduate scholarships for women, ethnic minorities and refugees.
Falcon Heavy flies
Three Falcon 9 first stages strapped together flew on 6 February 2018, carrying Musk's Tesla into a heliocentric orbit. The vehicle has since launched national security payloads, GOES-U, Europa Clipper and the Roman Space Telescope.
Gaia releases positions for 1.7 billion stars
The second data release gave parallaxes and proper motions at a precision that reset the distance scale, and it arrived as a public catalogue that anybody could query on the day.
Dies at 93
Roman died on 25 December 2018, having spent her last decades teaching high school science teachers, recording astronomy texts for blind readers, and telling young women that astronomy was a field they could enter.
A survey telescope takes her name
The observatory in Chile named for her will image the whole visible sky every few nights, and the resulting time-domain survey is aimed squarely at the problem she opened.
The first Starlink satellites appear as a train
Sixty satellites launched on 24 May 2019 and were immediately visible as a bright chain crossing the sky. Wide-field surveys started reporting streaked exposures, and the reflectivity of spacecraft became an astronomical problem for the first time.
The first Starlink satellites go up
Sixty satellites launched on 24 May 2019 and were visible from the ground as a bright chain. Astronomers reported streaked exposures within weeks, and satellite reflectivity became a research problem rather than a curiosity.
The US Space Force is stood up
Established on 20 December 2019 as an independent military branch. The Outer Space Treaty forbids weapons of mass destruction in orbit but not military use of space, and the line between support and weaponisation is where the argument now sits.
Schwarzschild precession measured
The orbit does not close on itself. It rotates slightly with each pass, exactly as general relativity requires in a field this strong.
WFIRST is renamed for her
On 20 May 2020 NASA announced that the Wide Field Infrared Survey Telescope would become the Nancy Grace Roman Space Telescope. Release 20-054 quotes Barbara Mikulski, who fought for Hubble in the Senate, calling it well deserved.
Crew Dragon carries astronauts
Demo-2 launched Doug Hurley and Bob Behnken on 30 May 2020, the first crewed launch from American soil since the Shuttle retired in 2011. Crew Dragon has been the primary ISS crew vehicle ever since.
The Nobel Prize in Physics
A quarter share, with Reinhard Genzel, for the discovery of a supermassive compact object at the center of our galaxy. Roger Penrose took the other half. She was the fourth woman to win the physics prize.
The first Artemis Accords signatures
NASA, the State Department and seven other founding nations signed on 13 October 2020. Signatories commit to transparency, interoperability, registration, open data and deconfliction zones. Turkiye became the seventy-first signatory on 31 August 2026.
The operating constellation passes 200
A launch of 48 SuperDoves in January 2021 took the active fleet above 200 satellites, enough for daily coverage of the entire land surface at 3 to 5 metres in eight spectral bands.
Planet goes public
The merger with a special purpose acquisition company completed on 7 December 2021, valuing the business at about $2.8 billion. Planet registered as a public benefit corporation, which binds it to a stated mission alongside shareholder return.
The Event Horizon Telescope images Sgr A*
The first direct picture of the shadow, produced by a global array of radio dishes, agreed with the mass the stellar orbits had already pinned down.
The IAU opens a centre for the problem
The Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference launched on 1 April 2022, co-hosted by NSF NOIRLab and the SKA Observatory. It coordinates measurement, mitigation and the case for regulation.
Gaia DR3 adds spectra to the census
Astrophysical parameters, radial velocities and low-resolution spectra for a large fraction of the catalogue. Cross-matching against it became a standard first step in almost any study.
Citizen star counts show the sky brightening at 9.6 per cent a year
Kyba and colleagues converted a decade of Globe at Night naked-eye star counts into a skyglow trend and found 9.6 per cent a year across Europe and North America, against roughly 2 per cent measured from orbit. Satellites are missing most of the change.
The launch tower catches a Super Heavy booster
On the fifth Starship flight test, 13 October 2024, the returning booster was caught between the tower arms instead of landing on legs. Removing landing hardware from the booster is central to the vehicle's cost case.
Falcon Heavy launches Europa Clipper
On 14 October 2024 the largest planetary spacecraft NASA has built left for a 2.9 billion kilometre cruise to Jupiter, arriving April 2030 for 49 flybys of Europa. It is the most ambitious outer solar system mission since Cassini.
Pelican-2 and a dedicated constellation deal
The next-generation high-resolution satellite launched on the Transporter-12 rideshare on 14 January 2025, with Pelican-3 and Pelican-4 following in August. In the same month SKY Perfect JSAT signed a $230 million deal for a dedicated ten-satellite constellation.
The free tropical forest basemaps end
Norway's Climate and Forests Initiative had paid for open access to high-resolution basemaps of 64 tropical countries, letting researchers and civil society track deforestation. The programme closed in April 2025.
Shutter control arrives
At US government request Planet restricted, then indefinitely banned, new imagery of the Middle East during the 2026 Iran war. Commercial imagery had been treated as an independent check on state accounts, and this showed the limits of that.
Rubin starts producing ten terabytes a night
The Legacy Survey of Space and Time began, with alerts on anything that changed brightness pushed out to broker systems within a minute of the shutter closing.
The Roman Space Telescope launches
Liftoff at 7:26 a.m. EDT on 30 August 2026, aboard a SpaceX Falcon Heavy from Launch Complex 39A at the Kennedy Space Center. The observatory separated cleanly, deployed its high-gain antenna and aperture cover, powered on its coronagraph on 1 September, and entered a commissioning period on the way to L2. First science images are expected in early 2027.
Falcon Heavy launches the Roman Space Telescope
Roman flew on 30 August 2026 toward Sun-Earth L2. It carries a Hubble-sized mirror with a field of view about a hundred times wider, for wide-area dark energy and microlensing surveys.