Here it is: the first-ever official image from the James Webb (JWST) space telescope. US President Joe Biden showed the photo to the world Monday evening (in the US) from the White House in Washington. The photo shows extremely distant galaxies. “This photo is the deepest photo of the universe ever,” says Ewine van Dishoeck. She is an astronomer at Leiden University and was involved in the development of the telescope for thirty years.
The largest and most powerful space telescope ever, JWST is the result of a collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). It has a price tag of about ten billion euros and it took roughly thirty years to build.
JWST was launched last December. This was followed by about six months in which the space telescope traveled 1.5 million kilometers, unfolded its 6.5-meter mirror and during which NASA technicians adjusted the colossus with commands from Earth. That was nerve-wracking, “there were more than three hundred moments when things could go wrong,” says Van Dishoeck. “But everything works and so far JWST has exceeded all expectations.”
Deflection
On Tuesday afternoon, NASA was due to share four first color photos of JWST with the world, but Biden had the honor of showing one on Monday evening. Extremely distant and faint galaxies are depicted in this image. To achieve this, scientists made clever use of a cosmological phenomenon. The galaxies, seen from Earth, lie behind galaxy cluster SMACS 0723. That cluster itself, seen in the foreground, lies 4.6 billion light-years from Earth. The cluster’s mass slightly bends the light traveling from even further galaxies to Earth, amplifying that light by the deflection. This effect is called the gravitational lens effect and acts like a magnifying glass. The further galaxies are also visible in the photo.
“Thanks to this effect, combined with the qualities of JWST, we can now look extremely far back into the universe,” says de Van Dishoeck. “The unveiling of JWST’s first color photograph is truly a milestone, JWST is a mission that we only experience once in a generation.”
Expanding gas cloud
NASA will publish the other three photos on Tuesday at 4:30 PM Dutch time. These will be photos of a group of galaxies 290 million light-years away, of one of the brightest and largest nebulae, and of an expanding gas cloud surrounding a dying star. In addition, NASA releases measurement data from a planet in another solar system.
“These photos are still just JPGs, by the way,” says Van Dishoeck. “They are meant to show the general public what JWST can do. On Wednesday, data will be added to the published photos in the archive, which we as scientists can use to conduct research. †