The start of the approximately ten billion dollar project by the American and Canadian space agencies NASA and ESA had been postponed again and again. Now the gigantic telescope, as it were packed as a package, is to take off on board an Ariane launcher in autumn and fly far deeper into space with its four infrared instruments than its predecessor, the “Hubble” space telescope, which has been in operation for more than 30 years.
Like a giant butterfly
But this harbors a risk: While “Hubble” was repaired and serviced several times with shuttle flights at an altitude of 500 kilometers, this is no longer possible with the “James Webb Space Telescope” at a distance of 1.5 million kilometers. According to Hasinger, the telescope with its 6.5 meter mirror and a tennis court-sized sun protection needs more than 130 individual mechanisms to unfold. “It’s a very, very complicated game that has to go through until everything is unfolded.” He compares it to a butterfly: “The caterpillar pupates, then the pupa breaks open – and the butterfly unfolds.”
This process begins on the way to the goal. “There are five points in the solar system at which gravity cancel each other out,” said Hasinger. The destination is one of them. There, with the earth and sun behind them and with the awning protected from heat radiation, the instruments could begin their measurements in different infrared waves. For this they are partly cooled down. “It will be the first cold telescope. If you want to measure infrared rays, which is heat radiation, then the telescope itself has to be very cold, ”said Hasinger.
First pictures in July 2022
It will take about seven months for the first examinations. Hasinger believes that the first pictures will probably be seen next July. According to the institute, an instrument co-developed by the Max Planck Institute for Astronomy in Heidelberg, a combination of camera and spectograph, is so sensitive that it could detect a candle burning on a Jupiter moon.
“Dense molecular clouds with a lot of dust and gas are the creation areas of new stars and planets. However, the dust absorbs the visible light that we are familiar with by sight, and it is therefore difficult or impossible for us to study their inner regions in detail, ”said Klaus Jäger from the Max Planck Institute. For the longer-wave infrared light, dust is a much smaller obstacle. “Observations in the infrared therefore allow us to look into these areas or to receive the infrared radiation from within.”
Exoplanets under a magnifying glass
According to Hasinger, a deep survey of the early expanding universe and a search of the star formation areas are planned with the telescope. “But then a large part of the observation time will go to the extrasolar planets.” The telescope could examine the atmosphere of such exoplanets for molecules that may indicate biological activity. “Whether that succeeds or not, of course, depends on whether we find the right planets.”
The strength of the telescope lies in its spectroscopy – that is, that you can take a chemical fingerprint from any point in the sky. “A picture is beautiful to look at. What we get with ‘James Webb’ is that we can read 1,000 other pieces of information in every single picture element, ”said Hasinger. For example, whether water is even possible anywhere. Near-Earth planets are of course interesting. “At some point you would like to find a planet that is as Earth-like as possible and where water exists and that is close enough that future generations may also be able to fly there.”
A second earth could possibly be found in this way. The telescope “will possibly be able to characterize whether there is oxygen or ozone or other possible biomolecules”. This is possible at a distance of up to 1,000 light years. Regarding dimension: A light year describes the distance that light travels in one year – almost 9.5 trillion kilometers. From the sun, which is around 150 million kilometers away, light takes about eight minutes to reach the earth.
Until the big bang
The telescope will be used to observe the first galaxies formed after the Big Bang, NASA Science Director Thomas Zurbuchen said at the beginning of June. Accordingly, it should offer a glimpse into the past 13.5 billion years ago – a lot further back than its predecessor “Hubble”.
“It will show us so much new that we will flap our ears,” said Hasinger. “James Webb” works in the infrared, “Hubble” in the optical and ultraviolet range. It would be ideal if Hubble continued to work as long as possible. “Because then you would get the entire ribbon of the rainbow.”
Hasinger expects the telescope, named after the former NASA boss James Edwin Webb, to have a lifespan of ten years. Then he’ll run out of fuel, so to speak. For the project, which has been in development for around 25 years, NASA initially expected costs of around $ 500 million. “The scientists and engineers at the time simply very, very much miscalculated,” says Hasinger.
How did the universe come about?
For Hasinger, however, the benefits of the ten billion dollar project are obvious. “People as such are curious and always try to understand everything in their environment.” The question is where do we come from and where are we going. “The question is, how did the universe come about and how will it develop further? How did the galaxy, the solar system, life come about? “
Jäger says: “In my opinion, one thing is already certain and is an experience from many other milestone projects: With” JWST “we will make discoveries that we do not yet suspect!”