Webb's First Deep Field facts for kids
Webb's First Deep Field is the first operational image taken by the James Webb Space Telescope, depicting SMACS 0723, a galaxy cluster 4.6 billion light-years from Earth in the constellation Volans. Revealed to the public on 11 July 2022, the composite image was taken by the telescope's Near-Infrared Camera (NIRCam) and covers a tiny area of sky visible from the Southern Hemisphere. Thousands of galaxies are visible in the image, which is the highest-resolution image of the early universe ever taken.
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Background
The James Webb Space Telescope (JWST) conducts infrared astronomy. Webb's First Deep Field was taken by the telescope's Near-Infrared Camera (NIRCam) and is a composite produced from images at different wavelengths, totaling 12.5 hours. The photo achieved depths at infrared wavelengths beyond the Hubble Space Telescope's deepest fields, which took weeks. The spacecraft has been orbiting Earth's second Lagrange point (L2), about 1.5 million kilometres (900,000 mi) from Earth, since 24 January 2022. At L2, the gravitational pulls of both the Sun and the Earth keeps the telescope's motion around the Sun synchronized with Earth's.
SMACS 0723 is a galaxy cluster of sky visible from Earth's Southern Hemisphere, and has often been examined by Hubble and other telescopes in search of the deep past.
Scientific results
The image shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago. Webb's image covers a patch of sky with an angular size approximately equal to a grain of sand held at arm's length by someone on the ground. Many of the cosmological entities depicted have undergone notable redshift due to the expansion of space over the extreme distance of the light radiating from them.
The combined mass of the galaxy cluster acted as a gravitational lens, magnifying much more distant galaxies behind it. Webb's NIRCam brought the distant galaxies into sharp focus, revealing tiny, faint structures that had never been seen before, including star clusters and diffuse features.
Significance
Webb's First Deep Field is the first full false color image from the JWST, and the highest-resolution infrared view of the universe yet captured. The image reveals thousands of galaxies in a tiny sliver of the universe, with Webb's sharp near-infrared view bringing out faint structures in extremely distant galaxies, offering the most detailed view of the early universe to date. Thousands of galaxies, which include the faintest objects ever observed in the infrared, have appeared in Webb's view for the first time.
It was first revealed to the public during a White House event on 11 July 2022 by U.S. president Joe Biden.
See also
In Spanish: Primer campo profundo del Webb para niños
- List of deep fields
