The Universe was born in darkness 13.8 billion years ago, and even after the first stars and galaxies formed several hundred million years later, they too remained dark. Their brilliant light, stretched through time and the expanding cosmos, was dimmed into the infrared, rendering them – and other clues to our beginnings – inaccessible to every eye and instrument.
Until now. On Tuesday, the James Webb Space Telescope, the most powerful space observatory built to date, offered a spectacular slideshow of our previously unseen nascent cosmos. Ancient galaxies covering the sky like jewels on black velvet. Young stars shining deep from cumulus clouds of interstellar dust. Evidence of water vapor in the atmosphere of a distant exoplanet.
Their sum is both a new vision of the universe and a view of the universe as it once looked new.
“It’s always been out there,” said Jane Rigby, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and the telescope’s operations manager. “We just had to build a telescope to see what was there.”
The Webb Telescope – NASA’s lauded successor to the Hubble Space Telescope, 30 years old and nearly 10 billion. It is a collaboration between NASA, the European Space Agency and the Canadian Space Agency.
“We’re looking for the first things to come out of the Big Bang,” said John Mather, the telescope’s lead project scientist.
President Biden offered a preview Monday afternoon as he presented what NASA officials and astronomers are calling the deepest image yet of the cosmos, a mark likely to be surpassed before the week is out when more data is spat out by NASA’s computers will.
The image of a distant star cluster called SMACS 0723 revealed the presence of even more distant galaxies scattered across the sky. The light from these galaxies, visualized by the cluster’s gravitational field, came from galaxies that existed more than 13 billion years ago.
Looking into space means looking into the past. Light travels through the vacuum of space at a constant rate of 186,000 miles per second, or almost 6 trillion miles per year. Observing a star 10 light-years away is seeing it as it existed 10 years ago, when light left its surface. The further away a star or galaxy is, the older it is, making every telescope a kind of time machine.
Astronomers suspect that the most distant early stars could be different than the stars we see today. The first stars were made of pure hydrogen and helium left over from the Big Bang, and they could grow much more massive than the Sun — and then collapse rapidly and violently into supermassive black holes of the kind that populate the centers of most galaxies today.
The new images were presented during an hour-long ceremony at the Goddard Space Flight Center moderated by Michelle Thaller, the center’s associate director for science communication, with video stops around the world. A few miles away at the Space Telescope Science Institute in Baltimore, a swarming crowd of astronomers cheered and roared, oohs and ahhs, as new images flashed onto the screen – proof their telescope was performing even better than hoped.
An infrared skyscape showed Stephan’s quintet, five galaxies incredibly densely packed in the constellation Pegasus. Four seem so close that they might eventually merge. Indeed, the image showed a dust band that was heated up as two of the galaxies ripped stars apart.
A look at the Southern Ring Nebula, the remains of an exploded star, revealed evidence of complex carbon molecules known as polycyclic aromatic hydrocarbons, or PAHs, floating at the center. Such molecules drift through space and settle in clouds, which then give birth to new stars, planets, asteroids – and whatever life might later sprout.
“Possibly the formation of PAHs in these stars is a very important part of the origin of life,” said Bruce Balick, professor emeritus of astronomy at the University of Washington. “I am shocked.”
The most striking image was of the Carina Nebula, a huge, swirling dust cloud that is both a stellar room and home to some of the most luminous and explosive stars in the Milky Way. Viewed in infrared, the nebula resembled a looming, eroded coastal cliff studded with hundreds of stars astronomers had never seen before.
“It took me a while to figure out what to call out in this image,” said Amber Straughn, assistant project scientist for the telescope, as she pointed to a rugged structure.
dr Straughn added that she couldn’t help but think of the size of the nebula, full of stars with planets of their own.
“We humans are really connected to the universe,” she said. “We are made of the same stuff in this landscape.”
By astronomers and at watch parties around the world there was unanimous relief and praise.
“I was blown away by this event,” said Alan Dressler, an astronomer at Carnegie Observatory who helped design the telescope 30 years ago. “I guess I’m not as jaded as I thought.”
He added: “The growth in our understanding of the universe will be as big as it was at Hubble, and that’s really saying something. We have a great adventure ahead of us.”
In an email, Sara Seager, a planetary scientist at the Massachusetts Institute of Technology, said: “When I read (last week?) that people cried when they first saw the images, I thought it was ridiculous. Now I feel like crying.”