James webb deep field

The James Webb Deep Field reveals thousands of distant galaxies, showing the universe as it was 13 billion years ago.

About this subject

The first deep field from the James Webb Space Telescope (JWST) was released on July 11, 2022, during a White House event. The image, known as Webb's First Deep Field, shows the galaxy cluster SMACS 0723, located about 4.6 billion light-years from Earth. Light from even more distant galaxies is distorted and magnified by the gravitational lensing effect of the cluster, allowing observation of objects that existed only 600 million years after the Big Bang.

The image was captured by JWST's NIRCam (Near-Infrared Camera) in just 12.5 hours of exposure, far less than the weeks required by Hubble for similar deep fields. The field of view covers a small patch of sky equivalent to a grain of sand held at arm's length. Thousands of galaxies appear, each containing billions of stars, in a diversity of shapes, colors, and ages.

JWST operates at infrared wavelengths, enabling it to see through dust clouds and detect the redshifted light of the most distant galaxies. The SMACS 0723 deep field is just one of many scientific projects for the telescope, which aims to understand the formation of the first stars and galaxies, the evolution of supermassive black holes, and the composition of exoplanet atmospheres.

The image has become an icon of the new era of astronomy, surpassing Hubble's deep fields, such as the Hubble Ultra Deep Field, by revealing unprecedented details of the early universe. Scientists use these data to study star formation rates over cosmic time and test models of galactic evolution.

Frequently Asked Questions

What is the James Webb Deep Field?

It is the first deep field image released by the James Webb Space Telescope, showing thousands of galaxies in the SMACS 0723 cluster, some seen as they were over 13 billion years ago.

How did JWST capture this image so quickly?

The telescope uses a 6.5-meter primary mirror and operates in the infrared, combined with gravitational lensing from the cluster, allowing it to collect light from distant objects with short exposures.

What is the difference between Webb's and Hubble's Deep Fields?

Webb sees in the infrared, detecting older, dustier galaxies that Hubble cannot see. Also, the image was obtained in hours, whereas Hubble took weeks.