A look at billions of years in the past and the possibility of discovering a second Earth for future generations: all this will soon be possible with a space telescope.
Scientists hope to get a look back at the early days of space after the Big Bang, 13.8 billion years ago. On images of stars older than our solar system that may no longer exist.
Perhaps evidence of a second Earth, a blue planet. With the launch of the James Webb Space Telescope (JWST) planned for the fall, researchers are expecting entirely new insights.
“It will simply open giant new windows and new possibilities,” says Esa’s Director of Science, Günther Hasinger.
James Webb operates 1.5 million kilometers away
The start of a nearly ten billion dollar project for the US and Canadian space agencies NASA and ESA has been repeatedly delayed.
Now the giant telescope, as packaged as a package, will take off aboard an Ariane launcher in the fall and fly 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.
But this carries risks: while Hubble has been repaired and maintained several times with shuttle flights at an altitude of 500 km, this is no longer possible with the James Webb Space Telescope at a distance of 1.5 million km.
According to Hasinger, the telescope, with its 6.5-meter mirror and a sunshade the size of a tennis court, needs more than 130 individual mechanisms to bloom. “It’s a very complicated game that has to pass until everything is revealed.” He compares it to a butterfly: “The caterpillar opens, then the pupa opens and the butterfly opens.”
The first images are expected to appear in July 2022
This process begins on the way to the goal. “There are five points in the solar system where gravity cancels each other out,” Hassinger says. Destination is one of them. There, with the Earth and the sun behind and with a canopy shielded from thermal radiation, the instruments could begin their measurements at various infrared wavelengths.
That is why they are partially cooled. It will be the first cool telescope. If you want to measure infrared, which is thermal radiation, the telescope itself has to be very cold,” Hassinger says.
The first exams will take about seven months. Hasinger believes the first images will likely appear in July. According to the institute, the instrument developed by the Max Planck Institute for Astronomy in Heidelberg, which is a combination of a camera and a spectrometer, is so sensitive that it can detect a burning candle on Jupiter’s moon.
“Dense molecular clouds with a lot of dust and gas are where new stars and planets form. However, dust absorbs visible light that we know by sight, and therefore it is difficult or impossible for us to study their interior in detail,” says Klaus Jäger of the Max Institute Plank.
Dust is a much smaller obstacle to long-wave infrared light. “Infrared observations allow us to look into these areas or receive infrared radiation from within.”
According to Hasinger, a deep survey of the early expanding universe and the search for regions of star formation with the telescope are planned. “But then a significant portion of the observation time will go to exoplanets.”
The telescope can examine the atmospheres of these exoplanets for particles that may indicate biological activity. “Whether that works or not depends of course on whether we find the right planets.”
Evidence for the existence of Earth-like planets
The telescope’s strength lies in its spectroscopy – that is, you can take a chemical fingerprint from any point in the sky. “The picture is beautiful when you look at it. What we get with James Webb is that we can read 1,000 more pieces of information in each element of the picture,” Hasinger says.
For example, whether water is possible anywhere. Near-Earth planets are of course interesting. “At some point, you want to find a planet that is as similar to Earth as possible and where there is water and that’s close enough so that future generations can fly there.”
So Earth 2 can be found. The telescope “will likely be able to determine if there is oxygen, ozone or other possible biomolecules.” This is possible at a distance of up to 1,000 light-years. Regarding distance: A light year describes the distance light travels in one year – about 9.5 trillion kilometers. From the Sun, which is about 150 million kilometers away, light takes about eight minutes to reach Earth.
Telescope lets look into the past
The first galaxies that formed after the Big Bang should be observed using a telescope, Thomas Zurbuchen, director of science at NASA, said at the beginning of June. Accordingly, it should provide a glimpse into the past 13.5 billion years – far beyond its predecessor, Hubble.
“It will show us so much new that we will just flutter our ears,” Hasinger says. James Webb works in the infrared, and Hubble works in the optical and ultraviolet range. It would be ideal if Hubble continued to operate for as long as possible. “Because then you’ll get the whole rainbow stripe.”
Hasinger predicts that the telescope, named after former NASA chief James Edwin Webb, will have a lifespan of up to ten years. Then the fuel will run out, so to speak. For the project, which was developed about 25 years ago, NASA initially expected costs to be about $500 million. “Scientists and engineers at the time miscalculated a lot,” Hasinger says.
But for Hasinger, the benefits of the $10 billion project are clear. “People like this are curious and always try to make sense of everything in their environment.” The question is, where did we come from and where are we going. The question is how did the universe originate and how will it evolve further? How did the galaxy, the solar system and life arise? “
Jäger says: “In my opinion, one thing is already certain and that is experience from many other important projects: with ‘JWST’ we will make discoveries we have not yet suspected!”
dpa
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