NASA launched the Hubble Space Telescope on April 24, 1990. Hubble has made more than a million observations, including detailed pictures of the birth and death of stars and galaxies billions of light years away.
On Dec. 25, 2021, NASA launched the James Webb Space Telescope, the most powerful telescope ever built. It’s able to see further and more clearly than any other telescope. Tap or click here to track Webb’s journey across the stars.
On July 11, we got the deepest and sharpest infrared image of the distant universe so far, but there’s more to it than you may catch at first glance. Here are four things you may not know about Webb’s first image.
1. You’re seeing a very, very old image
The first image NASA revealed shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago. Light travels 186,000 miles per second, so the light you see from the image has been traveling for more than 4.6 billion years to reach us!
2. Long exposure
Unless you have a tripod, you need a steady hand to hold your camera still long enough for an exposure lasting a few seconds. Now imagine doing it for hours.
Webb’s Near-Infrared Camera (NIRCam) is a composite made from images at different wavelengths, totaling 12.5 hours. And that’s nothing compared to Hubble, which took weeks to produce a picture like this.
Researchers plan to take even longer exposure shots with Webb, revealing more of the universe and its secrets.
RELATED: NASA’s Hubble Telescope just spotted the farthest star ever seen
3. Unimaginably huge (but also tiny)
According to the NASA Webb Telescope’s official Twitter account, “If you held a grain of sand up to the sky at arm’s length, that tiny speck is the size of Webb’s view in this image.”
Want to see how Hubble’s images stack up against Webb’s? Check out this excellent site, where you can use sliders to compare the same images from each telescope side-by-side: johnedchristensen.github.io/WebbCompare.
4. Bending light
See those swirly specks? The combined mass of the galaxy cluster acts as a gravitational lens, magnifying more distant galaxies. SMACS 0723 is warping space-time, bending light from galaxies even further away. We can see back more than 13 billion years thanks to this phenomenon!
“This is just the first image, and we’re going back further in the future to about 13.5 billion years,” NASA Administrator Bill Nelson said during Monday’s White House briefing. “Since we know the universe is 13.8 billion years old, we’re going back almost to the beginning.”
Bonus: 150 million pixels
Webb’s largest image so far, Stephan’s Quintet, is a visual grouping of five galaxies. The image contains over 150 million pixels and is constructed from nearly 1,000 separate image files.
It makes your 12MP smartphone cam seem sort of puny, doesn’t it?
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