It is the most expensive and the most ambitious space telescope that mankind has ever owned: it has been in place since the end of January James Webb Space Telescope (JWST) in orbit around the L2 Lagrange point – about 1.5 million kilometers from Earth. Gradually, in space, the giant sun shield and mirrors were unfolded. For a long time, the engineers at Nasa, Esa and the Canadian space agency CSA had trembled as to whether something else would go wrong that would affect the major international project or even turn it into a nine billion euro heap of space junk. But everything went – with the exception of a few micrometeorite impacts, which ended lightly – practically perfectly. The technicians could breathe easy. The first test images were already taken for the calibration, which gave an idea of what the telescope can do.
This test image from the James Webb telescope was taken over a period of eight days in early May. Stars can be recognized by their rays, everything else is galaxies.
(Photo: -/dpa)
On Monday, US President Joe Biden presented the first scientific image taken by the telescope. More spectacular pictures are to follow on Tuesday.
The picture, which the world public is now seeing for the first time, resembles a classic recording of Webbs predecessor, the Hubble-Space Telescope. That Webb fixed his gaze on a cluster of galaxies called SMACS 0723. The name stands for the southern extension (S) of the Massive Cluster Survey (MACS), a series of observations that have long cataloged particularly large clusters of galaxies. The section of sky now shown corresponds to about a grain of sand held at arm’s length compared to the entire universe, said NASA.
The galaxy cluster acts as a lens
In fact, the image is not about SMACS 0723 itself, but about what can be seen behind it. Because the galaxy cluster is so massive that it acts as a gravitational lens, amplifying and distorting the light from other objects. It acts as a natural telescope, helping to make very distant, faintly shining galaxies visible – at least for the super-sensitive eyes of the astronomer Webb-Telescopes. This creates a kind of panorama of this part of the sky, in which numerous galaxies can be seen at different distances and at different stages of their development.
It is the deepest look into the past of the universe that humans have ever managed – but it should only be the beginning. “The picture will not hold the record for long,” said Marcia Rieke of the University of Arizona, head of a camera team at the Webb-telescopes, the New York Times. “But it clearly shows the power of this telescope.”
An illustration of the JWST, with gold mirror and heat shield.
(Photo: Adriana Manrique Gutierrez/dpa)
Nice Hubble In 1995 he took the first panoramic picture called “Hubble Deep Field”, which is now one of the classics of astronomy. In the years that followed, several follow-up images were taken, showing a total of 265,000 galaxies up to 13.3 billion light-years away – meaning the light came from the early days of the universe, just around 400 million years after the Big Bang. Webb is said to have the potential to approach the Big Bang by up to 100 million years.
The “Hubble Ultra Deep Field”, an image from 2004.
(Photo: NASA/AFP)
That Webb-Telescope is Hubble clearly superior; his resolution is thanks Webbs enormous size better, and the telescope can pick up light of other wavelengths. While Hubble was particularly strong in the optical and ultraviolet ranges Webb especially with infrared light. This is an advantage if you want to look deep into space and thus far into the past: the further away an object is, the more its light is distorted by the expansion of space into the infrared range. In addition, infrared light can see through dust in space.