Less than a century ago, we—humans—believed that the universe ended at the very edge of the Milky Way. At the point where the last starlight of our home galaxy died out, endless nothingness began.
Until Edwin Hubble. The famous astronomer diligently scanned the sky for twinkling stars from Mount Wilson Observatory in California. His work with the Hooker telescope practically doubled the size of the Universe in 1923, when he and others helped reveal that Andromeda was not a tightly packed cluster of stars inside the Milky Way, but its very own galaxy, 2.5 million light-years away. Hubble knew the power of technological advances: bigger, better telescopes would help expand our horizons ever further.
Eighty years later, Hubble’s eponymous space telescope once again changed our view of the cosmic horizon with the release of the Hubble Ultra Deep Field imagea photograph of the Universe stretching so far back in space and time that it revealed galaxies born just 600 million years after the Big Bang.
Today, from July 11, 2022, our horizons are expanding again. A hundred years of progress – in the fields of telescopes, astronomy, astrophysics, engineering, rocket science, mathematics, hell, and even streaming online video – has led to NASA revealing the first image taken by the James Webb Space Telescope .
After a long wait that led to warming Online discussion about “Hold Music” by NASA TV, it was President Joe Biden who had the honor of posting Webb’s first look across the universe, an image dubbed “Webb’s first deep field” on Monday. The press conference only lasted 10 minutes and was a huge missed opportunitybut it provided a historical first picture from across the cosmos.
“If you hold a grain of sand on your fingertip at arm’s length, that’s the part of the universe you see — just a speck,” NASA Administrator Bill Nelson said during the press conference.
The full picture is below.
The deep field studies a corner of space known as SMACS 0723, which has been observed by space telescopes such as Hubble. It contains a giant galaxy cluster that acts as a lens, magnifying light from galaxies much further out into the cosmos.
One of the most notable aspects of this Webb image – and the images to come – is the six-pointed light you can see in the image, a function of the shape of the mirrors in the James Webb telescope.
There is also a circular spot of light in the center of the image. This is the “lensing” effect. The gravity of giant foreground clusters, only about 4 billion light-years away, is changing the way light from deep space reaches the telescope. In some cases, galaxies appear in two places because of the effect, and astronomers can examine this light to better understand what these deep galaxies look like.
When compared to the Hubble image of the same region, the difference is…stunning.
The image itself isn’t exactly “hot from the telescope.” Webb doesn’t see that. Webb’s imaging capabilities capture infrared light from cosmic objects in black and white, similar to Hubble, and image processing software is used to reveal all the intricacies of space. Those who helped create the images then pull off a technical and artistic feat: mapping infrared wavelengths to colors to emphasize key features in an image.
Some of the galaxies in the image existed just a few hundred million years after the Big Bang. We’re seeing them for the first time ever due to Webb’s powerful optics. What’s really interesting about them is that they appear larger than galaxies, which are technically much closer.
“The redder galaxies in the image are much further away from us than the blue ones, so you’d expect them to look smaller than the blue ones,” says Jonti Horner, an astrophysicist at the University of Southern Queensland in Australia. Instead, he notes, the redder galaxies look much larger due to a light quirk known as “angular diameter reversal.” It’ll give you a headache, but when these ancient galaxies first emitted light, the Universe was much more compact, meaning they were much closer together at the time. Yeh!
While the deep field delights, only the entree is. Tomorrow, NASA will provide a buffet of Webb images to enjoy a groundbreaking view of space. The release will highlight iridescent nebulae, illuminate alien worlds, and pull back the curtain on a cluster of colliding galaxies. If you go by that first picture, you should stuff yourself with those too. We’ve got you covered: here’s where and when to catch the Drop, but you can also watch the CNET Highlights livestream, which we’ve embedded below.
Updated at 6:00 PM PT: Comments added