“James Webb Vs Hubble” -written by Varun Bhalerao.
On July 11, 2022, The James Webb Space Telescope (JWST) released its first full-color image, which NASA commented as the “deepest, sharpest infrared view of the universe to date.” James Webb is the most powerful telescope ever launched into space and is said to be a promising successor to the Hubble Telescope. This blog presents a brief view of the image comparison between the two telescopes James Webb and Hubble.
SMACS 0723 :
The first image provided by NASA is a stunning view of the galaxy cluster SMACS 0723 in its most advanced version. The light from this galaxy cluster took so long to reach James Webb’s eye that it essentially provides a window to look into the universe at approximately 4.5 billion years ago.
Even Hubble also took the image of SMACS 0723 and it is worth noting that the image taken by Hubble required 10 days of exposure, while James Webb’s Near-Infrared camera image took only 12.5 hours to take the image of SMACS 0723. Hubble’s image on the left shows many faint stars and galaxies while James Webb’s image on the right absolutely pops with light, revealing many hidden structures. In addition, the redder galaxies are those that are farther away, with the wavelengths of their light stretched towards the red end by the expansion of the universe.
Furthermore, a cherry on the cake is the gravitational lens effect in James Webb’s image, visible as circular smearing of light in the center of the frame. The mass of the galaxy cluster is substantially warping the fabric of spacetime with its immense gravity; thus, bending and magnifying the light from other sources behind it. James Webb will be able to use this effect to peer even deeper into space, and as such, further back in time, than any other telescope so far.