NASA's James Webb telescope reveals the universe as we've never seen it before

By Joe Palca,

Published July 11, 2022 at 12:04 PM EDT

The James Webb Space Telescope (shown here being tested on earth) is expected to reveal some of the most spectacular views of the Universe ever seen.

Later today, the world should see something remarkable: an image of some of the first galaxies to form in the universe.

The picture will come from NASA's new, $10 billion James Webb Space Telescope. NASA had planned to release it tomorrow as part of a collection of the first scientific results, but apparently the image is so dramatic that the White House has determined that President Biden should be the one to reveal it to the world.

The James Webb Space Telescope is the most sophisticated observatory ever launched. It left Earth last December. In late January, it reached its celestial parking place a million miles away from the planet. Since then, engineers have been checking out the instruments, aligning the mirrors and letting the telescope cool down so its instruments will work properly.

"Webb was built to find the first generation of galaxies that formed after the big bang," says Jane Rigby, operations project scientist for the telescope. "That is the core science goal it was built to do."

Before declaring the telescope open for business mission managers wanted to make what they call early release observations. These are intended to show that the telescope works, and as Rigby says, "are intended to be jaw-droppingly beautiful, powerful both visually and scientifically."

In addition to the image containing the earliest galaxies ever seen, NASA will also release images of a stellar nursery where stars form called the Carina Nebula, the Southern Ring Nebula, and a group of galaxies discovered in 1787 called Stephan's Quintet. There will also be an analysis of the light coming from a giant planet orbiting outside our solar system with the prosaic name WASP-96b. Those additional images are expected to come out on Tuesday morning.

Looking Back To The Beginning

Webb is designed to gather and analyze infrared light, which is at longer wavelengths than can be seen by the human eye. That will allow it to capture light from the earliest galaxies, which appear in the infrared.

Those early galaxies are far away — more than 13 billion light years — and as powerful as the Webb telescope is, they may just look like faint smudges. But those smudges will help astronomers understand more about how the universe as we know it came to be.

One early target for the James Webb Space Telescope is a cluster of distant galaxies known as SMACS 0723. The gravitational field of these galaxies acts as a cosmic lens, allowing the telescope to look at far more distant and older parts of the universe.

One of the astronomers who will be conducting the search for those earliest galaxies is Caitlin Casey, an astronomer at the University of Texas at Austin.

She says one way to look for these faint galaxies is to point the telescope at the same patch of sky for a hundred hours or more, and let the light from these distant objects trickle in. The Hubble space telescope showed this so-called deep field approach could identify lots of previously unseen galaxies.

But where Hubble was able to see ten thousand galaxies in a deep field, with Webb, "we're going to have a million galaxies," Casey says.

Beyond finding new galaxies, Casey wants to understand the large structure of the universe, what the universe would look like if you could step back and get a birds eye view of it.

"If you zoom all the way out, the entire universe looks like, you know, something like the interior of a sponge where there are these like little filaments and voids," Casey says. "So what we really want to capture is that structure."

Much More To See

But that's just the beginning. The breadth of science Webb can be used for is staggering. For example, Megan Mansfield, a NASA Sagan Postdoctoral fellow at the University of Arizona, will be using Webb to study the atmospheres of planets orbiting stars outside our solar system.

In particular, she wants to know about their atmospheres — "what they're made of, what their temperature is." That will tell her a lot about the planet itself, and whether it might be capable of sustaining life.

Anna Nierenberg of the University of California, Merced, leads a team that has cooked up a clever way to use the new telescope to try to understand the fundamental nature of dark matter, that invisible stuff that makes up a quarter of the universe. "You simply can't do that with any other instrument," she says. "If everything works it will be a big deal."

And as with any scientific instrument with new capabilities, no one really knows what secrets the Webb telescope will reveal about the universe we live in.

NPR's Nell Greenfieldboyce contributed to this report.