News Bulliton

The universe was born in darkness 13.8 billion years ago, and even after the first stars and galaxies blazed into existence a few hundred million years later, these too stayed dark. Their brilliant light, stretched by time and the expanding cosmos, 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 yet built, offered a spectacular slide-show of our previously invisible nascent cosmos. Ancient galaxies carpeting the sky like jewels on black velvet. Fledgling stars shining out from deep within cumulus clouds of interstellar dust. Hints of water vapor in the atmosphere of a remote exoplanet.

Their sum is both a new vision of the universe and a view of the universe as it once appeared new.

“That was always 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 go see what was there.”

The Webb telescope — NASA’s vaunted successor to the Hubble Space Telescope, 30 years and nearly $10 billion in the making — is equipped to access this realm of cosmic history, study the first stars and galaxies and look for nearer, potentially habitable worlds. 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, senior project scientist for the telescope.

President Biden offered a preview on Monday afternoon when he introduced what NASA officials and astronomers hailed as the deepest image yet taken of the cosmos, a mark that will probably be passed before the week is done as more data spews forth from NASA’s computers.

The image, of a distant star cluster called SMACS 0723, revealed the presence of still more-distant galaxies spilled across the sky. The light from those galaxies, magnified into visibility by the gravitational field of the cluster, came from galaxies that existed more than 13 billion years ago.

To look outward into space is to peer into the past. Light travels at a constant 186,000 miles per second, or close to 6 trillion miles per year, through the vacuum of space. To observe a star 10 light-years away is to see it as it existed 10 years ago, when the light left its surface. The farther away a star or galaxy lies, the older it is, making every telescope a kind of time machine.

Astronomers theorize that the most distant, early stars may be unlike the stars we see today. The first stars were composed of pure hydrogen and helium left over from the Big Bang, and they could grow far more massive than the sun — then collapse quickly and violently into supermassive black holes of the kind that now populate the centers of most galaxies.

The new pictures were rolled out during an hourlong ceremony at the Goddard Space Flight Center that was hosted by Michelle Thaller, the center’s assistant director for science communication, with video stops around the world. A few miles away at the Space Telescope Science Institute in Baltimore, an overflow crowd of astronomers whooped and hollered, oohed and ahhed, as new images flashed on the screen — evidence that their telescope was working even better than hoped.

One infrared skyscape showed Stephan’s Quintet, five galaxies packed improbably tightly in the constellation Pegasus. Four appear to be so close together that they may eventually merge. Indeed, the image revealed a band of dust that was being heated up as two of the galaxies ripped stars from each other.

A view of the Southern Ring nebula, the remains of an exploded star, revealed hints of complex carbon molecules known as polycyclic aromatic hydrocarbons, or PAHs, floating in the midst. Such molecules drift through space, settling in clouds that then give birth to new stars, planets, asteroids — and whatever life might subsequently sprout.

“Possibly, the formation of PAHs in these stars is a very important part of how life got started,” said Bruce Balick, an emeritus professor of astronomy at the University of Washington. “I’m gobsmacked.”

The most striking image was of the Carina nebula, a vast, swirling cloud of dust that is both a star nursery and home to some of the most luminous and explosive stars in the Milky Way. Seen in infrared, the nebula resembled a looming, eroded coastal cliff dotted with hundreds of stars that astronomers had never seen before.

“It took me awhile to figure out what to call out in this image,” said Amber Straughn, deputy project scientist for the telescope, as she pointed to a craggy structure.

Dr. Straughn added that she could not help thinking about the scale of the nebula, full of stars with planets of their own.

“We humans really are connected to the universe,” she said. “We’re made out of the same stuff in this landscape.”

From astronomers and at watch parties around the globe, there was uniform relief and praise.

“This event blew me away,” said Alan Dressler, an astronomer at the Carnegie Observatory who was instrumental in planning for the telescope 30 years ago. “Guess I’m not as jaded as I thought.”

He added, “The growth in our understanding of the universe will be as great as it was with the Hubble, and that is really saying something. We’re in for a great adventure.”

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 that was ridiculous. Now I feel like crying.”

Source link

Leave a Reply

Your email address will not be published.

Social Media Auto Publish Powered By :