The 7 Most Powerful Space Telescopes
Neptune, as seen through the James Webb telescope's near-infrared camera
Telescopes can be ranked by effective optical aperture – the diameter of their light-gathering surface. This list includes optical telescopes, but not radio dishes or X-ray telescopes. Here are the seven largest space telescopes, measured by aperture width:
- James Webb Space Telescope: 256 inches (6.5 meters)
- Herschel Space Observatory: 138 inches (3.5 meters)
- Hubble Space Telescope: 94 inches (2.4 meters)
- Nancy Grace Roman Space Telescope: 94 inches (2.4 meters)
- Planck: 59 inches (1.5 meters)
- Euclid: 47 inches (1.2 meters)
- Kepler: 37 inches (0.95 meters)