Webb telescope reveals deepest image of early universe

The James Webb Space Telescope, the most powerful to be placed in orbit, has revealed the clearest image to date of the early universe, going back 13 billion years, US space agency NASA said Monday.

The stunning shot, released in a White House briefing by President Joe Biden, is overflowing with thousands of galaxies and features some of the faintest objects observed, colorized in blue, orange and white tones.

Known as Webb's First Deep Field, it shows the galaxy cluster SMACS 0723, which acts as a gravitational lens, bending light from more distant galaxies behind it towards the observatory, in a cosmic magnification effect.

Webb's primary imager NIRCam -- which operates in the near infrared wavelength spectrum because light from the early universe has been stretched out by the time it reaches us -- has brought these faint background galaxies into focus.

Webb compiled the composite shot in 12.5 hours, achieving well beyond what its predecessor the Hubble Space Telescope could in weeks.

"Fantastic -- galaxies upon galaxies upon galaxies," Jonathan Lunine, chair of the astronomy department at Cornell University, said, rejoicing with the rest of the global astronomy community.

"Even though this is by no means the farthest Webb can see, it's the deepest image ever taken, and shows the power of this remarkable telescope: tremendous sensitivity, a broad range of wavelengths, and sharp image clarity."

Avi Loeb, a professor of astronomy at Harvard, explained the reddish arcs are the ancient galaxies, while the light colored circles and ellipses belong to the younger galaxy cluster in the foreground.

He added he was "thrilled" about the idea of Webb looking even closer to the Big Bang, back some 13.8 billion years ago.