World’s Most Powerful Space Telescope – James Webb

The James Webb Space Telescope, NASA’s most powerful telescope, is scheduled to be rocketed into orbit no earlier than December 22. Though Webb is often called the replacement for the Hubble Space Telescope, NASA said it prefers to call it a successor.

Differences between Webb and the Hubble Telescope

Wavelength: The James Webb Space Telescope will observe primarily in the infrared range and provide coverage from 0.6 to 28 microns. The instruments on Hubble see mainly in the ultraviolet and visible part of the spectrum. It could observe only a small range in the infrared from 0.8 to 2.5 microns.

Size: Webb’s primary mirror has a diameter of 6.5 metres. Hubble’s mirror was much smaller – 2.4 metres in diameter. So, Webb will have a larger field of view compared to the camera on Hubble.

Orbit: Hubble orbits around the Earth at an altitude of ~570 km. Webb will not orbit the Earth. It will orbit the sun at about 1.5 million kilometres away from Earth.