Birth of Edwin Powell Hubble
Birth of Edwin Powell Hubble
Astronomy topic guide · World History Database
History of Space Telescopes
Placing telescopes above Earth’s atmosphere gives astronomers access to wavelengths that the atmosphere blocks and provides exceptionally stable observing conditions. Space astronomy developed from early ultraviolet, X-ray and infrared missions into multi-purpose observatories such as Hubble and specialised missions such as Chandra, Spitzer and Kepler. JWST extended major space-based observing capabilities into the infrared. Together these missions have transformed research on planets, stars, galaxies and the early universe.
What this chronology covers
Space observatories are designed around wavelength as much as around aperture. Earth’s atmosphere blocks or distorts much of the ultraviolet, X-ray and infrared sky, so orbital observatories can answer questions inaccessible to many ground-based instruments. Hubble became a broad ultraviolet-to-near-infrared observatory, Chandra specialised in X-rays, Spitzer in infrared astronomy, Kepler in precision photometry and JWST in infrared observations. Together they illustrate the increasingly specialised architecture of modern astronomical observing.
238matching astronomy records
2,423records in the complete astronomy database
Selected database timeline
The records below are drawn from the existing World History Database astronomy collection and arranged chronologically. For very broad subjects, the page shows a substantial selection rather than duplicating the entire parent database.
Discovery of Nebulae
Hubble announces that nearly all nebulae are associated with stars, and their illumination comes from star light
Hubble Space Telescope
Hermann Oberth, along with Robert Goddard and Konstantin Tsiolkovsky, one of the three fathers of modern rocketry, publish "Die Rakete zu den Planetenraumen" ("The Rocket into Planetary Space"), proposingg a telescope in space
Discovery of Cepheid Stars
Discovers a class of variable stars known as cephids existing outside our own galaxy
Cepheid Variables
Hubble identifies Cepheid variables in Andromeda and shows it lies beyond the Milky Way
Andromeda V1 Plate
Photographs M31 with the 100-inch Hooker telescope and records the star later recognized as Cepheid variable V1 on the famous VAR photographic plate.
Discovery of Cepheid Stars
Hubble establishes the distance to Cepheid variables in the Andromeda Galaxy, showing that Andromeda lies beyond the Milky Way and helping settle the Island Universe debate.
Island Universe
Settles the Island Universe debate which was concerned with whether the Milky Way and the Universe were synonymous, or was the Milky Way merely one in a plethora of galaxies that constitutes the Universe
Galaxies
Hubble announces evidence that spiral nebulae are external galaxies, expanding the scale of cosmology
Cepheid Variables Confirmed in Andromeda
Identifies multiple Cepheid variables in M31 and uses their periods to demonstrate that Andromeda is far outside the Milky Way.
Classification of Galaxies
Introduces the classification of galaxies as spirals, barred spirals & ellipticals
Andromeda Extragalactic Result Presented
Presents the Andromeda Cepheid evidence to the astronomical community, establishing M31 as a separate galaxy and greatly enlarging the known scale of the universe.
Galaxy Redshift
Humason begins measuring faint galaxy spectra that later strengthen Hubbles velocity distance relation
Hubble-Lemaitre Law
Lemaitre derives an expanding universe model and estimates the expansion rate from galaxy distances and velocities
Hubbles Law
Hubble and Milton L. Humason formulate what is now known as Hubbles law by combining Cepheid distances to several galaxies with Vesto Sliphers measurements of the speed at which those galaxies recede from us
Hubbles Law
The redshift in light coming from distant galaxies is proportional to their distance, the law is first formulated by Edwin Hubble and Milton Humason after nearly a decade of observations. Discovers Hubbles Law
Hubbles Law
The redshift in light coming from distant galaxies is proportional to their distance, the law is first formulated by Edwin Hubble and Milton Humason after nearly a decade of observations
Expanding Universe
Hubble publishes the velocity distance relation that makes expanding relativistic cosmology observationally compelling
Hubbles Law
Hubble publishes the velocity distance relation showing that galaxies recede faster at greater distances
Hubbles Law
Humason provides redshift measurements used by Hubble to support the velocity distance relation
White Dwarf Limit
Chandrasekhar combines quantum statistics with special relativity and identifies an upper mass beyond which a white dwarf cannot remain stable.
Asteroid 1373 Cincinnati
Discovers asteroid 1373 Cincinnati
Hubbles Law
When Edwin Hubble discovered a linear relationship between the distance to a galaxy and its redshift expressed as a velocity, Zwicky speculated that the effect was due not to motions of the galaxy, but to the slowing down of photons
Royal Astronomical Society
Winner of the Gold Medal of the Royal Astronomical Society
Hubble Space Telescope
The history of the Hubble Space Telescope can be traced back to 1946, when the astronomer Lyman Spitzer writes the paper "Astronomical advantages of an extraterrestrial observatory"
Discovery of Cepheid Stars
Recalculates the size of the known universe, doubling the previous calculation made by Hubble in 1929, announces this finding to considerable astonishment at the 1952 meeting of the International Astronomical Union in Rome
Hubbles Law
Sandage begins revising extragalactic distances and expansion measurements after Hubbles work
Death of Edwin Powell Hubble
Death of Edwin Powell Hubble
Hubbles Law
It was not until 1956 that Walter Baade corrected the distance scale based on Cepheid variable stars, and ushered in the first accurate measures of the expansion rate
Big Bang
Cosmological redshift is now conventionally understood to be a consequence of the expansion of space; a feature of Big Bang cosmology
Hubbles Law
Baade's revised Cepheid calibration doubles the extragalactic distance scale and improves measurements used to estimate the expansion rate of the universe.
Apollo Program
Becomes NASA administrator during Apollo expansion.
NASA
NASA Administrator James E. Webb announced the site of the NASA centre dedicated to human space flight would be Houston, Texas, this becomes the Manned Spacecraft Center, renamed the Lyndon B. Johnson Space Center in 1973
Interstellar Graphite Grains
Hoyle and Chandra Wickramasinghe proposed graphite particles as an important component of interstellar dust.
Hubble Space Telescope
In a report by the United States National Academy of Sciences recommends the development of a space telescope as part of the space program
Hubble Space Telescope
Spitzer is appointed as head of a committee given the task of defining the scientific objectives for a large space telescope
Hubble Constant
Sandage continues refining the expansion rate, an essential parameter for Big Bang age estimates
Diseases from Space
Publishes Diseases from Space with Chandra Wickramasinghe.
Space Travelers
Publishes Space Travelers with Chandra Wickramasinghe on the origins of life.
Evolution from Space
Publishes Evolution from Space with Chandra Wickramasinghe, extending their panspermia arguments.
IRS-1A
U. R. Rao oversees the launch of IRS-1A, beginning India's operational remote-sensing satellite series.
Hubble Space Telescope
The Hubble Space Telescope (HST) also known colloquially as "the Hubble" or just "Hubble", is a space telescope that is carried into orbit by the Space Shuttle Discovery, named for the American astronomer Edwin Hubble
Hubble First Light
Westphal's Wide Field and Planetary Camera team obtains Hubble's first image, demonstrating sharper resolution than typical ground-based observations.
Hubble Mirror Spherical Aberration
NASA identifies spherical aberration in Hubble's primary mirror, explaining the blurred appearance of the telescope's early images.
Supernova 1987A Ring Resolved
Hubble resolves a gaseous ring around Supernova 1987A in unprecedented detail during one of the observatory's earliest science investigations.
First Hubble Science Paper
Lauer submits the first science paper based on Hubble observations, studying the core of galaxy NGC 7457.
Large Magellanic Cloud Distance
Hubble observations of Supernova 1987A help determine the Large Magellanic Cloud's distance to about 169,000 light-years.
First Hubble Jupiter Images
Hubble obtains its first detailed observations of Jupiter, including views of the Great Red Spot.
Hubble Images Andromeda Double Nucleus
Hubble observations resolve two distinct brightness peaks in the central region of M31, revealing the unusual double structure of its nucleus.
INSAT-2A
U. R. Rao oversees the launch of INSAT-2A, the first satellite in India's indigenously developed second-generation INSAT series.
NGC 4261 Black Hole Disk
Hubble reveals a disk of material in the core of NGC 4261 that appears to feed a massive central black hole.
M81 Cepheid Distance
Freedman leads Hubble Cepheid measurements that refine the distance to galaxy M81 and improve estimates of the universe's age.
Andromeda Double Nucleus Announced
NASA announces Hubble evidence that the core of M31 contains a double nucleus, challenging simple models of the galaxy's central stellar structure.
Hubble Servicing Mission 1 Launch
Covey commands Endeavour as the first Hubble servicing mission launches with a crew trained to repair and upgrade the telescope.
Hubble Captured for Servicing
Nicollier uses Endeavour's robotic arm to capture Hubble and secure it in the payload bay for the first servicing mission.
Hubble Gyroscope Replacement
Musgrave begins the first servicing spacewalk and helps replace Hubble gyroscopes and their electrical control units.
Hubble Solar Array Replacement
Thornton helps replace Hubble's original solar arrays with improved arrays designed to better tolerate orbital temperature changes.
Hubble Damaged Solar Array Released
Thornton releases a damaged original Hubble solar array that cannot be safely returned inside Endeavour.
WFPC2 Installed on Hubble
Hoffman helps replace Hubble's original planetary camera with WFPC2, whose corrective optics compensate for the primary mirror flaw.
COSTAR Installed on Hubble
Akers helps install COSTAR, providing corrective optics for three Hubble science instruments affected by spherical aberration.
Hubble Orbit Boost
Bowersox pilots orbital maneuvers that raise Endeavour and Hubble into a higher orbit, extending the telescope's orbital lifetime.
Hubble Solar Array Electronics Repair
Musgrave helps replace solar-array drive electronics and complete magnetometer and electrical work during the mission's final spacewalk.
Hubble Released After First Servicing
Nicollier uses Endeavour's robotic arm to release the repaired Hubble back into orbit after Servicing Mission 1.
Hubble Servicing Mission 1 Completed
Covey commands Endeavour's return to Earth after the successful first Hubble servicing mission.
Pluto
Hubble's Faint Object Camera images Pluto through much of a rotation, enabling an image-based map of most of its surface.
Pluto
Hubble observations record strong large-scale brightness differences across Pluto's surface at unprecedented spatial resolution.
Great Dark Spot Disappears
Hubble observations show that the large southern dark storm seen by Voyager 2 has disappeared.
Eta Carinae Hubble Imaging
Hubble images reveal detailed structure around the unstable massive star Eta Carinae and its violent surrounding ejecta.
M87 Massive Black Hole
Leads Hubble observations of rapidly orbiting gas in M87, providing strong evidence for a massive black hole at the galaxy's centre.
Hubble Imaging of Shoemaker-Levy 9 Impacts
Leads Hubble observations documenting atmospheric scars from the Shoemaker-Levy 9 impacts on Jupiter.
New Northern Dark Spot
Hubble detects a new large dark storm forming in Neptune's northern hemisphere.
Titan Surface Features
Hubble observations produce the first images resolving large-scale surface brightness features on Saturn's moon Titan.
Neptune Dark Spot Announced
Hammel's Hubble observations are announced as evidence that Neptune's large dark storms can appear and disappear rapidly.
Oxygen Detected on Europa
Hall's Hubble spectroscopy identifies oxygen in Europa's tenuous atmosphere, the first such detection around a planetary satellite.
Pillars of Creation
Hester leads Hubble imaging of towering star-forming columns in the Eagle Nebula that become known as the Pillars of Creation.
Betelgeuse Surface Image
Dupree helps produce Hubble's first direct image resolving the surface of a star other than the Sun, revealing Betelgeuse's ultraviolet hot spot.
Hubble Deep Field
Williams directs the Hubble Deep Field program, combining hundreds of exposures into an unprecedented deep view containing thousands of galaxies.
Beta Pictoris Disk Warp
Burrows leads Hubble observations showing a warp in the Beta Pictoris dust disk consistent with gravitational influence from an unseen planet.
Pluto
Hubble results produce the first image-based surface map of Pluto, revealing about a dozen major bright and dark regions.
Pluto
The Hubble surface map confirms a dark equatorial belt and bright polar regions on Pluto.
Pluto
Hubble observations indicate Pluto's surface patterns are strongly influenced by migrating nitrogen and methane frosts.
Hubble Servicing Mission 2 Launch
Bowersox commands Discovery as the second Hubble servicing mission launches to install new instruments and maintain the observatory.
Hubble Captured for Second Servicing
Hawley operates Discovery's robotic arm to capture Hubble and secure the telescope for Servicing Mission 2.
STIS Installed on Hubble
Lee helps install the Space Telescope Imaging Spectrograph, extending Hubble's ability to study spectra across a broad wavelength range.
NICMOS Installed on Hubble
Smith helps install NICMOS, giving Hubble powerful new near-infrared imaging and spectroscopic capability.
Hubble Fine Guidance Sensor Replaced
Harbaugh helps replace a degraded Fine Guidance Sensor and upgrade Hubble's precision pointing capability.
Hubble Tape Recorder Replaced
Tanner helps replace a failed Engineering and Science Tape Recorder during the second servicing mission.
Hubble Data Interface Unit Replaced
Lee helps replace a Data Interface Unit that routes commands and information between Hubble spacecraft systems.
Hubble Solid State Recorder Installed
Smith helps replace a reel-to-reel recorder with a digital solid-state recorder capable of simultaneous recording and playback.
Hubble Reaction Wheel Replaced
Lee helps replace a reaction wheel assembly used to turn Hubble toward targets and maintain stable pointing.
Hubble Solar Array Drive Electronics Replaced
Tanner helps replace electronics that control the positioning of Hubble's solar arrays.
Hubble Thermal Insulation Repaired
Harbaugh installs new thermal blankets over degraded insulation around Hubble's light shield.
Hubble Electronics Insulation Added
Smith attaches thermal insulation over key Hubble data-processing, electronics and instrument-telemetry areas during the final spacewalk.
Hubble Servicing Mission 2 Completed
Bowersox commands Discovery's return after Hubble is released as a more capable observatory following Servicing Mission 2.
M84 Black Hole Signature
Hubble spectroscopy maps rapidly moving gas in galaxy M84 and records a clear dynamical signature of a supermassive black hole.
Io Volcanic Plume
Spencer leads Hubble observations of an enormous volcanic plume rising hundreds of kilometres above Jupiter's moon Io.
Chandra Observes Andromeda Core
NASA's Chandra X-ray Observatory obtains a deep view of the M31 nucleus and surrounding X-ray sources, including emission near the central black hole position.
Hubble Servicing Mission 3A Launch
Brown commands Discovery as an urgent Hubble servicing mission launches after multiple gyroscope failures force the telescope into safe mode.
Hubble Captured for Servicing Mission 3A
Clervoy operates Discovery's robotic arm to capture Hubble for the emergency Servicing Mission 3A.
Hubble Rate Sensor Units Replaced
Smith helps replace all three Hubble Rate Sensor Units, restoring six gyroscopes used for accurate telescope pointing.
Hubble Gyroscope Repair
Grunsfeld helps restore Hubble's pointing system by replacing failed gyroscope assemblies during the first Servicing Mission 3A spacewalk.
Hubble Advanced Computer Installed
Foale helps install a new Hubble computer approximately twenty times faster than the telescope's original flight computer.
Hubble Fine Guidance Sensor Installed
Nicollier helps install a new Fine Guidance Sensor during Servicing Mission 3A.
Hubble Transmitter Replaced
Grunsfeld helps install a replacement transmitter for sending Hubble scientific data to the ground.
Hubble Digital Recorder Installed
Smith helps replace an older mechanical data recorder with a solid-state digital recorder during the final spacewalk.
Hubble Released After Servicing Mission 3A
Clervoy uses Discovery's robotic arm to release Hubble after repairs restore the observatory to science operations.
Missing Intergalactic Hydrogen
Hubble quasar spectroscopy reveals extensive filaments of ionized hydrogen between galaxies, helping account for matter missing from the nearby universe.
Sagittarius A Star X-Ray Flare
Leads Chandra observations detecting rapid X-ray flaring from Sagittarius A*, revealing activity from matter close to the Galactic Centre black hole.
Orion Protoplanetary Disks
Hubble images provide direct visual evidence of planet-building material in dusty disks around young stars in the Orion Nebula.
Chandra Maps X-Ray Sources in Andromeda
Chandra results reveal numerous X-ray binaries in the central region of M31 and isolate an X-ray source consistent with the position of its supermassive black hole.
First Exoplanet Atmosphere Measurement
Hubble detects sodium in the atmosphere of HD 209458b, providing the first direct atmospheric measurement of an exoplanet.
Quaoar Direct Size Measurement
Trujillo and Brown use Hubble observations to obtain the first direct resolved size measurement of a Kuiper Belt object.
Hubble Servicing Mission 3B Launch
Altman commands Columbia as Servicing Mission 3B launches to replace Hubble solar arrays and install major new hardware.
Hubble Captured for Servicing Mission 3B
Currie uses Columbia's robotic arm to capture Hubble and secure it for the servicing crew.
Hubble Starboard Solar Array Replaced
Linnehan helps replace Hubble's starboard solar array with a more powerful third-generation array.
Hubble Solar Arrays Completed
Newman helps complete installation of Hubble's new solar arrays, increasing the observatory's available electrical power.
Hubble Reaction Wheel Assembly Replaced
Massimino helps replace a reaction wheel assembly used to control Hubble's orientation and stable pointing.
Hubble Power Control Unit Replaced
Grunsfeld helps install a new Power Control Unit after Hubble is completely powered down for the first time in orbit.
Advanced Camera for Surveys Installed
Newman helps install the Advanced Camera for Surveys, replacing Hubble's Faint Object Camera.
NICMOS Cooling System Installed
Linnehan helps install an experimental cooling system that returns Hubble's NICMOS infrared instrument to operation.
Hubble Released After Servicing Mission 3B
Currie uses Columbia's robotic arm to release the upgraded Hubble back into orbit.
Hubble Servicing Mission 3B Completed
Altman commands Columbia's landing after the successful Hubble Servicing Mission 3B.
Pluto Moons
Hubble images of the Pluto system provide an earlier comparison epoch later used in searches for faint satellites.
Crab Pulsar Dynamics
Hubble and Chandra observations reveal rapidly changing shocks and structures around the energetic pulsar inside the Crab Nebula.
Hubble Supernova Constraints
Knop leads analysis of Supernova Cosmology Project events observed with Hubble, tightening constraints on matter density and the dark-energy component.
Pluto
Hubble completes a series of observations later combined into detailed maps showing changes in Pluto's surface appearance.
Evaporating Exoplanet Atmosphere
Vidal-Madjar leads Hubble observations showing hydrogen escaping from HD 209458b in an extended comet-like atmosphere.
V838 Monocerotis Light Echo
Bond leads Hubble imaging of expanding light echoes produced when the eruptive star V838 Monocerotis illuminates surrounding dust.
Cosmic Transition from Deceleration
Riess uses very distant Type Ia supernovae to identify evidence that the universe once decelerated before dark energy became dominant and expansion began accelerating.
Hubble Servicing Mission 4 Cancelled
O'Keefe cancels the planned fourth Hubble servicing mission because of shuttle safety concerns following the Columbia disaster.
Hubble Ultra Deep Field
Astronomers unveil the Hubble Ultra Deep Field, a million-second exposure revealing galaxies seen when the universe was only several hundred million years old.
Spitzer Infrared Survey of Andromeda
Spitzer records thousands of infrared exposures of M31, mapping warm dust and star-forming structures that are difficult to isolate in visible light.
Pluto Moons
Hubble images reveal two faint candidate satellites near Pluto, later named Nix and Hydra.
Pluto Moons
A second Hubble observing epoch shows the two candidate moons moving with Pluto, strengthening the satellite interpretation.
Deep Impact Comet Observation
Hubble records Comet Tempel 1 before and after NASA's Deep Impact projectile strikes the comet nucleus.
Spitzer Reveals Off-Centre Star Formation Ring
Spitzer infrared imaging shows an asymmetric ring of star formation and a gap in Andromeda's disk, suggesting past interactions with satellite galaxies.
Pluto Moons
NASA publicly announces Hubble's discovery of two possible additional moons orbiting Pluto.
Discovery of Vanth
Hubble images obtained by Brown reveal a moon orbiting the large trans-Neptunian object Orcus.
Uranus New Rings and Moons
Showalter leads Hubble observations revealing two previously unknown dusty rings around Uranus and the moons Mab and Cupid.
Dark Energy Detected in Young Universe
Riess uses distant Hubble supernovae to trace acceleration farther back in time and strengthen evidence that dark energy behaves approximately like a cosmological constant.
Neptune Atmospheric Monitoring
Long-term Hubble observations continue tracking changes in Neptune's clouds and large-scale atmospheric features.
Discovery of Weywot
Hubble observations reveal a small moon orbiting Quaoar, later named Weywot.
Comet 73P Breakup
Weaver helps lead Hubble observations showing the detailed fragmentation of Comet 73P/Schwassmann-Wachmann 3 as it approaches the Sun.
Spitzer Estimates Andromeda Stellar Mass
Infrared measurements from Spitzer are used to estimate the mass of Andromeda's stars and to characterize the distribution of its old stellar population.
Pluto Moons
The International Astronomical Union approves the names Nix and Hydra for Pluto's two small moons discovered with Hubble.
Bullet Cluster Dark Matter
Clowe combines Hubble lensing observations with other data to map dark matter separately from hot gas in the Bullet Cluster.
GALEX and Spitzer Multiwavelength Andromeda View
A combined ultraviolet and infrared view separates hot young stellar populations from cool dusty star-forming regions across M31.
Inner Dust Ring Linked to M32 Collision
Spitzer observations reveal an inner dust ring whose geometry supports a past near head-on passage of the companion galaxy M32 through Andromeda's disk.
Hubble Servicing Mission 4 Reinstated
Griffin reinstates Hubble Servicing Mission 4 after NASA develops additional shuttle safety and risk-mitigation measures.
Comet Holmes Outburst
Hubble resolves fine structures in Comet 17P/Holmes after the comet suddenly brightens by nearly a millionfold.
Methane in Exoplanet Atmosphere
Swain leads Hubble observations detecting methane in HD 189733b, the first organic molecule identified in an exoplanet atmosphere.
Hubble Servicing Mission 4 Delayed
A failure in Hubble's Science Instrument Command and Data Handler causes NASA to delay Servicing Mission 4 until a replacement can be flown.
Chandrayaan-1
Mylswamy Annadurai serves as project director when Chandrayaan-1 launches on India's first mission to the Moon.
Fomalhaut Exoplanet Imaging
Kalas leads Hubble observations that reveal a visible-light point source moving around Fomalhaut within its debris system.
Lunar Water Evidence
Chandrayaan-1 observations obtained during Mylswamy Annadurai's project leadership contribute to strong evidence for hydroxyl and water molecules on the lunar surface.
Hubble Constant Narrows Dark Energy Models
Riess improves the Hubble constant measurement, reducing the range of dark-energy models allowed when local expansion data are combined with early-universe observations.
Hubble Servicing Mission 4 Launch
Altman commands Atlantis as the final Hubble servicing mission launches to repair and modernize the observatory.
Hubble Captured for Final Servicing
McArthur uses Atlantis's robotic arm to capture Hubble for the telescope's fifth and final astronaut servicing mission.
Wide Field Camera 3 Installed
Grunsfeld helps replace WFPC2 with Wide Field Camera 3, greatly expanding Hubble's ultraviolet, visible and infrared imaging capability.
Hubble Soft Capture Mechanism Installed
Feustel helps install a soft-capture mechanism intended to support a future robotic rendezvous with Hubble.
Related astronomers
AryabhataProfile and database timelineBhaskara IIProfile and database timelineNicolaus CopernicusProfile and database timelineTycho BraheProfile and database timelineGalileo GalileiProfile and database timelineJohannes KeplerProfile and database timelineEdmond HalleyProfile and database timelineWilliam HerschelProfile and database timeline
Sources and editorial provenance
Compiled and edited by World History Database
Historical chronology compiled from the World History Database and checked against major scientific and historical reference sources.
Last reviewed: September 2026.
- Royal Museums Greenwich — History of astronomy
- Royal Museums Greenwich — History of the telescope
- NASA Science — Hubble timeline
- NASA Science — Exoplanet discovery history
- LIGO — GW150914 first gravitational-wave detection
- Event Horizon Telescope — first black-hole image
- NASA Webb — mission science and discoveries