Our view of the universe has just expanded.
The first image from NASA’s new space telescope unveiled is brimming with galaxies and offers the deepest look of the cosmos ever captured.
The James Webb Space Telescope's initial capture is the farthest humanity has ever seen in both time and distance, closer to the dawn of time and the edge of the universe.
That image will be followed on Tuesday by the release of four more galactic beauty shots from the telescope’s initial outward gazes.
The “deep field" image released on Monday during a brief White House event is filled with numerous stars, with massive galaxies in the foreground and faint and extremely distant galaxies peeking through here and there.
The shot shows SMACS 0723 — a cluster of galaxies in the Southern Hemisphere constellation, Volans — with the cluster itself some 4.6 billion light-years away.
Part of the image is light from not too long after the Big Bang, which was estimated to have taken place 13.8 billion years ago.
President Joe Biden marvelled at the image that he said showed “the oldest documented light in the history of the universe from over 13 billion — let me say that again — 13 billion years ago. It’s hard to fathom.”
The busy image with hundreds of specks, streaks, spirals and swirls of white, yellow, orange and red — the gravitational warping effect as the light traverses immense distances to reach the telescope — is only “one little speck of the universe,” NASA Administrator Bill Nelson said.
“What we saw today is the early universe,” Harvard astronomer Dimitar Sasselov said in a phone interview after the reveal.
Sasselov said he and his colleague Charles Alcock first thought “we’ve seen this before." Then they looked closer at the image and pronounced the result not only beautiful but "worth all that waiting” for the much-delayed project.
And even more is coming Tuesday. The pictures on tap include a view of a giant gaseous planet outside our solar system, two images of a nebula where stars are born and die in spectacular beauty and an update of a classic image of five tightly clustered galaxies that dance around each other.
What is the Webb Telescope?
The James Webb Space Telescope is a revolutionary apparatus designed to peer through the cosmos to the dawn of the universe.
Webb, which views its subjects chiefly in the infrared spectrum, is about 100 times more sensitive than its 30-year-old predecessor, the Hubble Space Telescope, which orbits Earth from 547 km away and operates mainly at optical and ultraviolet wavelengths.
Hubble has stared as far back as 13.4 billion years. It found the light wave signature of an extremely bright galaxy in 2016.
Astronomers measure how far back they look in light-years, with one light-year being 9.3 trillion km — the distance light covers in one Earth year.
“Webb can see backwards in time to just after the Big Bang by looking for galaxies that are so far away that the light has taken many billions of years to get from those galaxies to our telescopes,” Jonathan Gardner, Webb’s deputy project scientist said during a June media briefing.
The larger light-collecting surface of Webb's primary mirror — an array of 18 hexagonal segments of gold-coated beryllium metal — enables it to observe objects at greater distances, thus further back in time, than Hubble or any other telescope.
Its infrared sensitivity allows it to detect light sources that would otherwise be hidden in the visible spectrum by dust and gas.
Taken together, these features are expected to transform astronomy, providing the first glimpse of infant galaxies dating to just 100 million years after the Big Bang, the theoretical flashpoint that set the expansion of the known universe in motion an estimated 13.8 billion years ago.
Webb's instruments also make it ideal to search for signs of potentially life-supporting atmospheres around scores of newly documented planets orbiting distant stars and to observe worlds much closer to home, such as Mars and Saturn's icy moon Titan.
At 6.4 metres, Webb’s gold-plated, flower-shaped mirror is the biggest and most sensitive ever sent into space.
It’s comprised of 18 segments, one of which was smacked by a bigger than anticipated micrometeoroid in May. Four previous micrometeoroid strikes to the mirror were smaller. Despite the impacts, the telescope has continued to exceed mission requirements, with barely any data loss, according to NASA.
“I’m now really excited as this dramatic progress augurs well for reaching the ultimate prize for many astronomers like myself: pinpointing Cosmic Dawn — the moment when the universe was first bathed in starlight,” said Richard Ellis, professor of astrophysics at University College London.
A parking spot 1.6 million km from Earth
The €8.93 billion infrared telescope, the largest and most complex astronomical observatory ever sent to space, was launched on Christmas Day from French Guiana, on the northeastern coast of South America.
A month later, the 6,350-kg instrument reached its gravitational parking spot in solar orbit, circling the sun in tandem with Earth nearly 1.6 million km from home.
Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate and calibrate the science instruments, all protected by a sunshade the size of a tennis court that keeps the telescope cool.
The plan is to use the telescope to peer back so far that scientists will get a glimpse of the early days of the universe about 13.7 billion years ago and zoom in on closer cosmic objects, even our own solar system, with sharper focus.
How far back past 13 billion years did that first image look? NASA didn't provide any estimates on Monday.
Outside scientists said those calculations will take time, but they are fairly certain somewhere in the busy image is a galaxy older than humanity has ever seen, probably back to 500 million or 600 million years after the Big Bang.
“It takes a little bit of time to dig out those galaxies,” University of California, Santa Cruz, astrophysicist Garth Illingworth said. “It's the things you almost can't see here, the tiniest little red dots.”
“This is absolutely spectacular, absolutely amazing,” he added. “This is everything we’ve dreamed of in a telescope like this”.
Webb's other pictures
With Webb now finely tuned and fully focused, astronomers will embark on a competitively selected list of science projects exploring the evolution of galaxies, the life cycles of stars, the atmospheres of distant exoplanets and the moons of our outer solar system.
The first batch of photos, which have taken weeks to process from raw telescope data, offers a compelling glimpse at what Webb will capture on the science missions that lie ahead.
Among the five celestial subjects chosen for NASA's showcase debut of Webb are two nebulae — enormous clouds of gas and dust blasted into space by stellar explosions that form nurseries for new stars — and two sets of galaxy clusters.
One of those, according to NASA, features objects in the foreground so massive that they act as "gravitational lenses," a visual distortion of space that greatly magnifies the light coming from behind them to expose even fainter objects farther away and further back in time.
How far back and what showed up on camera remains to be seen.
NASA will also publish Webb's first spectrographic analysis of an exoplanet, revealing the molecular signatures from patterns of filtered light passing through its atmosphere.
The exoplanet in this case, roughly half the mass of Jupiter, is more than 1,100 light-years away.
"Moved me as a scientist... as a human being"
All five of Webb's introductory targets were previously known to scientists. One of them, the galaxy group 290 million light-years from Earth known as Stephan's Quintet, was first discovered in 1877.
But NASA officials promise Webb's imagery captures its subjects in an entirely new light, literally.
"What I have seen moved me as a scientist, as an engineer and as a human being," NASA deputy administrator Pam Melroy, who has reviewed the images, told reporters during a news briefing on June 29.
Klaus Pontoppidan, a Webb project scientist at the Space Telescope Science Institute in Baltimore, where mission control engineers operate the telescope, has promised the first pictures would "deliver a long-awaited 'wow' for astronomers and the public".
Besides a host of studies already lined up for Webb, the telescope's most revolutionary findings may prove to be those that have yet to be anticipated.
Such was the case in Hubble's surprising discovery, through observations of distant supernovas, that the expansion of the universe is accelerating, rather than slowing down, opening a new field of astrophysics devoted to a mysterious phenomenon scientists call dark energy.
The Webb telescope is an international collaboration led by NASA in partnership with the European and Canadian space agencies.
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2022-07-12 06:13:27Z
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