A great leap forward in space science was achieved a few weeks ago, when the first photographs from the recently-launched James Webb Space Telescope were released.
Among those rejoicing at the spectacular views of deep space was University of South Carolina astronomy professor Varsha Kulkarni, whose two proposals to use the telescope to study space dust were accepted by NASA. “I was just blown away,” she said of her first sight of the images. “They were so much more impressive than anything I would have imagined.”
Even considering the amazing pictures of stars, nebulas and more obtained from the long-serving Hubble space telescope, Kulkarni said the Webb can pick up much, much more detail.
“You can see a lot more detail in it, structures that were previously not at all visible. And the fainter galaxies that were not visible, we can pick out them as well,” she said of Webb’s increased powers of detection. Looking to the future, she predicted, “in years to come we’ll get much deeper images that will go really much farther than Hubble could ever go. And even when Hubble took its deepest image, it was actually looking at a fairly blank-looking piece of sky. And we had no idea that we would see thousands of galaxies, even in that picture.”
But see these galaxies astronomers did, and more. South Carolina State Museum Planetarium Manager Liz Klimek listed some of the many celestial objects the new pictures reveal. “There’s the Carina Nebula…one of the exoplanets…they’ve got the edge of a star-forming region, they got a galaxy cluster, the atmosphere of a planet orbiting around another star, a planet in another solar system, and they got…a group of interacting galaxies. So many different types of things. It just kind of shows the variety of things that Webb will be able to look at.”
Klimek said space scientists were expecting to be wowed, and they were. “I am continually amazed at the performance of this telescope because of how complex it is,” she enthused. “I expected a few issues, and the images that came down are just...it’s not just one image, it’s a bunch of them, and they’re just so crisp, and they just look perfect and of so many different objects, and they look amazing. It’s really just hard to describe.”
According to Klimek, different wavelengths of light – chiefly infrared – allow astronomers to see things they couldn’t see before. “It’s kind of like with a person. You see a person and they look the way they look, but now you take an x-ray. And then you’re looking at different wavelengths of light and you’re getting information differently, and now you have a more complete picture of a person because you used some other wavelength of light. And so that’s what we’re doing, we’re getting a more complete picture of certain objects with Webb, because it can see colors that Hubble could not see.”
Kulkarni said the Webb gathers more information than the Hubble similarly to the way photographic film gathers more information when exposed to light for longer periods of time.
“For any telescope, the longer you expose, the more light you’re collecting,” she said, calling Webb’s more numerous light-gathering mirrors “kind of like a bucket. If you have a bucket of water, the size of the bucket decides how much water you collect. So the bigger your bucket, the more efficiently you collect. So in this case you have a bigger light bucket, Webb compared to Hubble.”
The light that Webb will be able to see may be as old as 12 billion years or more, allowing scientists to “look back in time” at an era when some stars, which burned out long ago, were emitting light that is still travelling through the universe, to Earth and beyond. According to Kulkarni, the Webb telescope is expected to be in service for about 20 years, perhaps longer with luck.
What excites Klimek is the understanding of our universe and history that can be increased by the Webb’s information. “What is our story? Not just ‘how did we get here to earth,’ but how did the solar system get here?” she wondered. “How’d this galaxy form, and going back as far as we can, and what our origins and how did it all come together? And how did it turn into all the wonderful things we see today?
“How did those little faint red blobs you see in that Webb deep field, how did that turn into these big, grand beautiful spirals like the Milky Way that we’re a part of today? And that’s what we want to know. I think that inspires people, even if you’re not into astronomy.”
Very soon, Kulkarni actually will use the Webb telescope to study space dust for its chemical composition, and its relationship to star formation. She and Klimek stressed that the information gathered by the telescope is public, and all data it gathers eventually will be released. Klimek said it’s exciting that we don’t know what we’ll find, and that’s part of the adventure.
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