№ 639. Cosmos: Webb v Hubble

 

A Technological Marvel

How does the Webb compare with the Hubble telescope? 

The Webb telescope’s primary mirror is 6.5 meters in diameter, compared with Hubble’s, which is 2.4 meters, giving Webb about seven times as much light-gathering capability and thus the ability to see further out in space and so deeper into the past. 

 

Another crucial difference is that Webb is equipped with cameras and other instruments sensitive to infrared, or “heat,” radiation. The expansion of the universe causes the light that would normally be in wavelengths that are visible to be shifted to longer infrared wavelengths that are normally invisible to human eyes.

For perspective about the size of the mirror, two engineers are seen in the bottom right of the photo, which was snapped at a Northrop Grumman testing control room in Southern California. (The telescope's overall design and construction, however, is a collaboration between NASA, ESA, and the Canadian Space Agency.)