# The most important space telescopes in history

From Hubble to James Webb, from X-rays to infrared: the space telescopes that showed us the origins of the universe, black holes and thousands of exoplanets. Which one contributed most?

- 0 votes · 23 items
- Oct 14, 2025 · gg.wandering
- https://even.best/en/l/2829/the-most-important-space-telescopes-in-history

## Top 23

1. **Hubble Space Telescope** (0 · ▲0 ▼0) — Launched in 1990, it took the famous "Hubble Deep Field" images.
2. **James Webb Space Telescope** (0 · ▲0 ▼0) — Launched in 2021, with a 6.5-metre mirror, it studies the early universe in infrared.
3. **Chandra X-ray Observatory** (0 · ▲0 ▼0) — Launched in 1999, the most sensitive X-ray telescope.
4. **Spitzer Space Telescope** (0 · ▲0 ▼0) — Launched in 2003, it helped reveal the seven planets of TRAPPIST-1.
5. **Compton Gamma Ray Observatory** (0 · ▲0 ▼0) — Launched in 1991, it detected thousands of gamma-ray bursts.
6. **Kepler Space Telescope** (0 · ▲0 ▼0) — Launched in 2009, it confirmed more than 2,600 exoplanets.
7. **TESS** (0 · ▲0 ▼0) — Launched in 2018, it scans almost the whole sky for planets.
8. **Gaia** (0 · ▲0 ▼0) — Launched in 2013, it mapped more than 1.5 billion stars in 3D.
9. **Herschel Space Observatory** (0 · ▲0 ▼0) — Launched in 2009, a 3.5-metre mirror for far-infrared.
10. **Planck** (0 · ▲0 ▼0) — It precisely measured the cosmic microwave background.
11. **Fermi Gamma-ray Space Telescope** (0 · ▲0 ▼0) — Launched in 2008, Compton's successor.
12. **Swift** (0 · ▲0 ▼0) — Launched in 2004, it quickly pinpoints gamma-ray bursts.
13. **Einstein Observatory** (0 · ▲0 ▼0) — 1978, the first fully imaging X-ray telescope in space.
14. **XMM-Newton** (0 · ▲0 ▼0) — The European X-ray telescope launched in 1999.
15. **NICER** (0 · ▲0 ▼0) — Installed on the ISS in 2017, it studies neutron stars.
16. **WMAP** (0 · ▲0 ▼0) — Launched in 2001, it mapped the cosmic microwave background before Planck.
17. **IRAS** (0 · ▲0 ▼0) — 1983, the first all-sky infrared survey.
18. **Hipparcos** (0 · ▲0 ▼0) — 1989, the first astrometry mission.
19. **Spektr-R** (0 · ▲0 ▼0) — 2011, Russia's space radio telescope.
20. **Uhuru** (0 · ▲0 ▼0) — 1970, the first X-ray astronomy satellite.
21. **ROSAT** (0 · ▲0 ▼0) — It discovered more than 100,000 new X-ray sources.
22. **CHEOPS** (0 · ▲0 ▼0) — Launched in 2019, it measures the sizes and densities of exoplanets.
23. **International Ultraviolet Explorer** (0 · ▲0 ▼0) — 1978, the first dedicated ultraviolet space telescope.

How is this ranking ordered? By people's votes: each ▲ adds a point and each ▼ takes one away. Anyone can vote and add what is missing.