Webb Space Telescope
Seeing the invisible
Get to the root of it
The James Webb Space Telescope, to be launched in 2013, is NASA’s next orbiting telescope.
Webb, like the Spitzer Space Telescope, will view the universe in wavelengths that cannot be seen by the human eye. Webb will observe infrared light. Objects that are not quite hot enough to glow with visible light glow with infrared light. Infrared light also pierces layers of dust that can hide objects in space, allowing Webb to see objects that would normally be blocked from view.
Long time traveling
Infrared astronomy is important because light from the most distant objects in space is also light that started traveling billions of years ago. Because the universe is expanding, visible light gets stretched as it travels through space, turning it into infrared light.
Earth’s atmosphere blocks most infrared light coming from space. In addition, sources of infrared light on Earth interfere with observations. These factors make it difficult to do infrared astronomy on our planet. Some infrared telescopes are positioned on mountaintops, where the atmosphere is thin, but one of the best places to do infrared astronomy is in space.
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| Year to be launched: | 2013 |
| Telescope type: | Reflector |
| Light collector: | Gold-coated beryllium mirror |
| Mirror diameter: | 255.6 inches (6.5 m) |
| Light observed: | near- to mid-infrared |
- Telescope has not launched.