Differences between Webb and Hubble telescopes

Subject – Science and Tech

Context – The James Webb Space Telescope, NASA’s most powerful telescope, is scheduled to be rocketed into orbit no earlier than December 22.

Concept –

Though Webb is often called the replacement for the Hubble Space Telescope, NASA said it prefers to call it a successor.
Launched into low Earth orbit in 1990, the Hubble Space Telescope has made more than 1.4 million observations, including tracking interstellar objects, capturing a comet colliding with Jupiter, and discovering moons around Pluto.
- Hubble has captured galaxies merging, probed supermassive black holes and has helped us understand the history of our universe.

Parameter	James Webb	Hubble
Wavelength	Observe primarily in the infrared range. (The infrared region of the electromagnetic spectrum covers the wavelength range from approximately 0.7 to a few 100 microns)	See mainly in the ultraviolet and visible part of the spectrum
Size	Webb’s primary mirror has a diameter of 6.5 metres. Webb also carries a large sun shield.	Hubble’s mirror was much smaller – 2.4 metres in diameter.
Orbit	Webb will not orbit the Earth. It will orbit the sun at about 1.5 million kilometres away from Earth.	Hubble orbits around the Earth at an altitude of ~570 km.
How far can the telescope see?	Webb Telescope will be able to see “baby galaxies”. Webb’s near- and mid-infrared instruments will help study the first formed galaxies, exoplanets and birth of stars.	Hubble can see the equivalent of “toddler galaxies”

Webb vs Herschel Space Observatory

In 2009, the European Space Agency launched an infrared telescope named the Herschel Space Observatory.
It also orbits the Sun similar to how Webb would. The primary difference between Webb and Herschel is the wavelength range: Webb goes from 0.6 to 28 microns, while Herschel covers 60 to 500 microns.
Also, Herschel’s mirror is smaller than Webb’s. It is 3.5 metres in diameter, while Webb’s primary mirror has a diameter of 6.5 metres.