Significance of James Webb Space Telescope’s First Deep Field image from NASA

Significance of James Webb Space Telescope’s First Deep Field image from NASA

Subject :Science and Technology

Section :Space

Context:

NASA’s James Webb Space Telescope (JWST) delivered its deepest and sharpest infrared image of a distant universe to date
What is the First Deep Field?
A composite made from images at various wavelengths captured by the JWST’s Near-Infrared Camera (NIRCam)

It is Known as Webb’s First Deep Field, the image is of galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago

The distortion seen in the image is the result of an effect called gravitational lensing

Webb’s NIRCam has brought those distant galaxies into sharp focus – they have tiny, faint structures that have never been seen before, including star clusters and diffuse features
James Webb Space Telescope (JWST):

• It has long been touted as the successor to the long-serving Hubble Space Telescope (HST)
  It is designed specifically for infrared astronomy, allowing it to spot these incredibly distant objects.
  JWST to peer deeper into the history of the universe and glean insights into the formation of star systems a mere 100 million to 250 million years after the Big Bang

Hubble Space Telescope (HST)
The HST, launched in 1990, was designed primarily as an optical space observatory optimised for capturing light at wavelengths visible to the human eye.

• This, however, turned out to be a limitation when it came to observing the distant universe and some of the earliest galaxies in the cosmos.
• Due to the expansion of the universe, the further away an object is from the Earth, the faster it moves away.
• This gives rise to an effect called red shifting, wherein light emitted from the object (even if it is initially of a shorter wavelength) is stretched into longer wavelengths and becomes redder
  Since infrared light is outside the visible spectrum and because Hubble is optimised for capturing light at visible wavelengths, extremely distant objects, which appear very red, are invisible to the HST

Concept:

A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known as gravitational lensing.