What JWST, Hubble, Rubin, Euclid and the next giant telescopes have discovered, how they work, and what launches or switches on next.
By The Orbital Record editorial teamPublished Last reviewed
Space telescopes are observatories in orbit, above the atmosphere that blurs and blocks much of the light from space; the best known are Hubble (1990) and the James Webb Space Telescope (2021). Giant ground telescopes such as Rubin and the Extremely Large Telescope, and survey missions such as Euclid and Roman, complete the picture.
This guide is the map: which observatories are working in October 2026, what they have found, how they see back in time, and what switches on next. Each one has its own hub page; all of them are on the observatory map.
As of October 2026, these are the major space telescopes doing science:
| Telescope | Agency | Launched | Light it sees | Known for |
|---|---|---|---|---|
| Hubble | NASA and ESA | 1990 | Ultraviolet, visible, near-infrared | Deep fields, the accelerating universe, 22,000+ papers |
| James Webb (JWST) | NASA, ESA and CSA | 2021 | Infrared | The earliest galaxies, exoplanet atmospheres |
| Chandra | NASA | 1999 | X-rays | Black holes, supernova remnants, hot gas in clusters |
| Euclid | ESA | 2023 | Visible and near-infrared | A 3D map of dark matter and dark energy |
| TESS | NASA | 2018 | Visible and red light | Transiting planets around nearby stars |
| XRISM | JAXA with NASA | 2023 | X-rays | High-resolution X-ray spectra of hot gas |
| SPHEREx | NASA | 2025 | Infrared, 102 colors | An all-sky spectral map of galaxies and ices |
| Roman | NASA | August 2026 | Infrared | Commissioning; dark energy and a planet census to come |
ESA’s Gaia, which mapped about a billion Milky Way stars, ended observations in January 2025 and was switched off in March 2025; its fourth data release is due on December 2, 2026.
In four years, JWST has rewritten several chapters of astronomy. Five highlights:
The full, dated roundup is in what JWST has discovered.
JWST and Hubble are partners, not rivals.
| Hubble | JWST | |
|---|---|---|
| Mirror | 2.4 m | 6.5 m, 18 segments |
| Light | Ultraviolet, visible, near-infrared | Infrared, 0.6 to 28.5 micrometers |
| Orbit | Low Earth orbit | Sun-Earth L2, about 1.5 million km away |
| Launched | 1990 | 2021 |
| Serviceable | Yes, five shuttle missions | No |
Hubble has worked in one-gyroscope mode since June 2024 but is still producing science. The side-by-side comparison, with what each sees best, is in JWST vs Hubble.
Every telescope is a time machine because light takes time to travel. We see the Sun as it was about eight minutes ago, Andromeda as it was 2.5 million years ago, and the most distant galaxies as they were more than 13 billion years ago. Looking farther means looking earlier.
The expanding universe adds a twist: it stretches light on the way, shifting it toward longer, redder wavelengths. This redshift is how astronomers measure cosmic distances, following the relation Edwin Hubble published in 1929 (Hubble’s law). For the earliest galaxies, the stretch is so large that their ultraviolet light arrives as infrared, which is why JWST was built as an infrared telescope and why it is kept so cold.
The lookback has a limit. Before about 380,000 years after the Big Bang the universe was an opaque fog of hot plasma, so no telescope that uses light can see earlier than the cosmic microwave background, the afterglow released when that fog cleared. Galaxies themselves only began to form a few hundred million years later, and that is the era JWST now probes. To look further back than the microwave background, astronomers will need other messengers, such as gravitational waves from the very early universe.
Some of the biggest discoveries come not from staring at one target but from mapping everything.
The Vera C. Rubin Observatory on Cerro Pachón, Chile, released its first images in June 2025, issued its first alerts in February 2026 and began its ten-year Legacy Survey of Space and Time (LSST) in mid-2026, announced on June 30 (Rubin begins the LSST). Its 8.4-meter telescope and 3,200-megapixel camera, the largest digital camera ever built, image the entire southern sky every few nights, revisiting each spot about 800 times and producing up to about 7 million alerts per night. In early tests alone it found more than 11,000 new asteroids. The survey design is set out in Ivezić et al. 2019, and the first data in Rubin Data Preview 1.
ESA’s Euclid, launched in July 2023, is mapping 14,000 square degrees of sky to trace dark matter through weak gravitational lensing and galaxy clustering (the Euclid mission). In July 2026 Euclid and Keck reported 12 new quasars above redshift 7. Its first large data release covers about 1,900 square degrees from November 2026.
The Dark Energy Spectroscopic Instrument (DESI) on Kitt Peak, Arizona, uses 5,000 robotic fibers to measure distances to tens of millions of galaxies. Its 2025 results strengthened the hint that dark energy is weakening over time (DESI DR2), and in April 2026 it finished its planned five-year map ahead of schedule (DESI completes its 3D map).
Gaia measured the positions, distances and motions of about a billion stars from 2014 to 2025 (the Gaia mission), transforming the study of the Milky Way. Its data release in December 2026 is expected to include the first large set of exoplanet candidates found by astrometry.
Dated milestones, as published by each agency as of October 2026:
| Observatory | Type | Milestone | Date |
|---|---|---|---|
| Gaia | Space, retired | Data Release 4 | December 2, 2026 |
| Roman | Space, infrared | Commissioning, first images | Early 2027 |
| PLATO (ESA) | Space, planet hunter | Launch on Ariane 6 | March 2027 |
| SKA Observatory | Ground, radio | Science verification begins | From 2027 |
| Extremely Large Telescope | Ground, 39 m optical | First light / start of science | March 2029 / December 2030 |
| Giant Magellan Telescope | Ground, 25.4 m optical | Completion | 2030s |
| Ariel (ESA) | Space, exoplanet atmospheres | Launch | 2031 |
| PRIMA (NASA) | Space, far-infrared | Target launch | 2033 |
| LISA | Space, gravitational waves | Launch | Mid-2030s |
| Habitable Worlds Observatory | Space, Earth-like planets | Possible launch | 2040s |
NASA selected PRIMA in September 2026 as the first mission in its new Probe class (NASA advances PRIMA). Roman itself launched on August 30, 2026 (Roman launches).
Ranked by the diameter of the main mirror or dish:
Radio arrays such as ALMA and the planet-sized Event Horizon Telescope work differently: they combine many dishes to act like one telescope as wide as the distance between them, which is how the EHT imaged the shadow of a black hole (M87*, 2019).
Two new kinds of “telescope” do not use light at all.
These messengers complement light. When two neutron stars collided in 2017, gravitational-wave detectors pinpointed the event and dozens of ordinary telescopes then caught the glow of freshly made heavy elements (GW170817). Combining all the messengers, light, neutrinos and gravitational waves, is now called multi-messenger astronomy.
For a look inside the world’s next giant, our video library includes ESO’s tour of the Extremely Large Telescope under construction and Scott Manley’s explainer on how JWST unfolded in space.
As of October 2026, major working space telescopes include Hubble, the James Webb Space Telescope, the Chandra X-ray Observatory, ESA's Euclid, NASA's TESS and SPHEREx, and the Japanese-led XRISM. NASA's Nancy Grace Roman Space Telescope launched in August 2026 and is being commissioned on its way to its observing orbit.
Yes. As of October 2026 the James Webb Space Telescope is fully operational and in its fifth observing cycle, which began on July 1, 2026, after a record 2,930 proposals. NASA estimates it carries enough propellant for roughly 20 years of operations from its 2021 launch.
Because the light of the first galaxies has been stretched into the infrared by the expansion of the universe, and because infrared passes through dust that hides newborn stars and planets. Cool objects such as exoplanets and brown dwarfs also shine mostly in infrared, which JWST sees from 0.6 to 28.5 micrometers.
NASA's Nancy Grace Roman Space Telescope launched on August 30, 2026, at 7:26 a.m. EDT on a SpaceX Falcon Heavy from Kennedy Space Center. It is traveling to the Sun-Earth L2 point, about 1.5 million kilometers away, with first images expected by early 2027 and a primary mission of at least five years.
The Legacy Survey of Space and Time is a ten-year survey by the Vera C. Rubin Observatory in Chile, which began in mid-2026. Its 8.4-meter telescope and 3,200-megapixel camera photograph the entire southern sky every few nights, producing a time-lapse of the universe and millions of alerts about changing objects.
The largest single-dish radio telescope is China's 500-meter FAST. The largest optical telescope in operation is the 10.4-meter Gran Telescopio Canarias in La Palma. ESO's Extremely Large Telescope in Chile, with a 39-meter mirror, will take the optical title when it sees first light, targeted for 2029.
After Roman, the next major space observatories include ESA's PLATO planet hunter, planned for March 2027, ESA's Ariel exoplanet mission in 2031, NASA's proposed far-infrared PRIMA probe around 2033, the LISA gravitational-wave observatory in the mid-2030s, and NASA's Habitable Worlds Observatory concept for the 2040s.
Light travels at a finite speed, so we see distant objects as they were when the light left them. Light from the Sun is about eight minutes old; light from Andromeda left 2.5 million years ago; light from the most distant galaxies JWST has confirmed set out more than 13 billion years ago.
Jansky, Proceedings of the IRE, 21, 1387-1398, 1933
Detected in 1933 the first radio waves from space. Karl Jansky traced a steady hiss to the center of the Milky Way, founding radio astronomy.
Giacconi et al., Physical Review Letters, 9, 439-443, 1962
Detected in 1962 the first X-ray source beyond the Solar System, Scorpius X-1. Riccardo Giacconi's rocket experiment opened the field of X-ray astronomy.
York et al., The Astronomical Journal, 120, 1579-1587, 2000
Described in 2000 the Sloan Digital Sky Survey, built to map a quarter of the sky and a million galaxies. Donald York's paper set up big-data astronomy.
IceCube Collaboration, Science, 342, 1242856, 2013
Found in 2013 the first evidence for high-energy neutrinos from beyond the Solar System. The IceCube Collaboration saw 28 events, 4 sigma above background.
Gaia Collaboration, Astronomy & Astrophysics, 595, A1, 2016
Described in 2016 ESA's Gaia, built to chart the positions, distances and motions of over a billion stars. Prusti's paper is the mission's reference guide.
Ivezić et al., The Astrophysical Journal, 873, 111, 2019
Described in 2019 the design of the Legacy Survey of Space and Time. Ivezić and colleagues planned Rubin's 10-year movie of the sky, begun in 2026.
Rigby et al., Publications of the Astronomical Society of the Pacific, 135, 048001, 2023
Measured in 2023 how the James Webb Space Telescope performed in commissioning. Jane Rigby's team found it better than expected almost across the board.
Euclid Collaboration, Astronomy & Astrophysics, 697, A1, 2025
Described in 2025 ESA's Euclid, built to probe dark matter and dark energy over 14,000 square degrees. Mellier and the Euclid team set out the plan.
Vera C. Rubin Observatory Team, The Astronomical Journal, 171, 360, 2026
Described in 2026 Rubin Observatory's first data: 1,792 exposures over 15 square degrees, with 2.3 million objects and 93 new Solar System bodies.
Recorded hours before launch, Scott Manley explains the James Webb Space Telescope, why it cost so much, why it was delayed and how its folded design unfolds in space. Strong on engineering detail. Scott Manley
Explains very long baseline interferometry, the technique the Event Horizon Telescope used to link radio dishes worldwide and image Sagittarius A*, the black hole at the Milky Way's center. A clear guide to the method. Veritasium
Tom Scott visits ESO's Extremely Large Telescope in Chile, likely the largest optical telescope that will ever be built, and explains the asterisk in that claim. Light, engaging and well filmed. Tom Scott
ESO's own 2026 tour of the Extremely Large Telescope under construction, from the structure inside the dome to the facility that coats its mirror segments with silver. A short look behind the scenes. ESO Chasing Starlight
Becky Smethurst walks through the first images from the Vera C. Rubin Observatory, first proposed in 2001 and built over about 15 years, and why astronomers waited so long for them. Accessible and enthusiastic. Dr. Becky
A zoom through Euclid's first 208-gigapixel mosaic, covering more than 500 times the area of the full Moon and some 14 million galaxies. Three minutes of pure visuals from ESA's dark universe mission. European Space Agency, ESA
Explains the Habitable Worlds Observatory, a large space telescope planned for the 2040s to directly image Earth-like planets around Sun-like stars in visible light. A good look at the next big exoplanet mission. Dr. Becky