Lillian Eden, MetroWest Daily News
Sun, January 2, 2022,
Aiming to look to galaxies far, far away, the James Webb Space Telescope has left Earth from Kourou, French Guiana, on a journey of nearly a million miles.
Its mission is simple: science in space that’s never been done before. The telescope will be able to look at the first galaxies of the universe during their infancies and see if planets orbiting other stars have indications of life, including oxygen, water and atmospheres.
That’s according to Irene Porro, director of the Christa Corrigan McAuliffe Center for Integrated Science Learning in Framingham.
Although the launch has been frequently delayed, the Christmas morning launch went off without a hitch and can be streamed on NASA’s website.
Irene Porro
“This is the mission of the century,” Porro said ahead of the launch. “I truly believe that what we will learn with Webb will affect the life of almost everyone on planet Earth. Not because we all of a sudden become astronomers, no, it’s a kind of insight, perspective, a new view on the universe — literally — and it’s accessible to everyone.”
What makes the Webb Telescope unique?
“Often, James Webb is being referred to as a followup to Hubble, but in a way, I would prefer to think about it as a compliment,” Porro said. “It’s not going to do the same kind of science, it’s going to do science that the Hubble couldn’t do.”
The main differences between the two telescopes are size, the type of light they will detect and where the JWST will be — namely, 930,000 miles away at a Lagrange Point, where the pull from both the Earth and the sun will help keep the telescope in orbit.
The JWST is quite a bit larger than the Hubble Space Telescope, which went in to low orbit around Earth in 1990. The Hubble is about as long as one of the letters of the Hollywood sign in California, and it’s only 14 feet wide. Fully deployed, the JWST will have a sun shield about the size of a tennis court attached to a collection of hexagonal mirrors more than 20 feet wide.
The JWST will spend some of its time looking at the same objects the Hubble Space Telescope, viewing them in infrared as opposed to visible light. When you look at someone, you are able to do that by seeing visible light — what the Hubble telescope can observe. But if you look at someone through an infrared camera, you can still see the person, but their shape is defined by temperature — which parts are warmer or cooler.
“If I were eating some ice cream, you literally would see ice cream going down my esophagus,” Porro explained. “Using different parts of the spectrum of light, we’ll see different characteristics of an object. Webb will be able to look at the same objects Hubble looked at and see different phenomena that Hubble couldn’t see.”
It will take about a month for the JWST to reach its destination and, if all goes well, six months will be spent calibrating and fine tuning the telescope. Then it will finally begin making observations.
How can the JWST look back in time?
If the light on the moon were to suddenly be turned off, it would take more than a second for people on Earth to notice — the amount of time it takes for light from the moon to reach the planet.
That same principle, on a much larger scale, is why the JWST is being touted as a way to see through time. Light first created billions of years ago is still traveling across the galaxy.
For example, if a planet 65 million light years away were to train a telescope on Earth right now, it wouldn’t see the planet in its present form; instead, it would observe what was happening on Earth 65 million years ago. In that case, the dinosaurs.
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Over such an expanse of time and distance, that light may be very weak. That's why the new telescope has a sun shield, Porro said, for the same reason that lights are dimmed in movie theaters and fireworks are best enjoyed in the dark.
“We are looking for this very faint infrared light from out there, and we are flooded in infrared light coming from the sun, the Earth and our own instruments,” Porro said. “The shield has really that main role of blocking all the infrared light.”
A wider perspective
Porro stressed that while this project is a complex and technical mission, it's also an opportunity for more perspective.
“It shows that humans are so creative and capable," she said. "We don’t have to go out there ourselves, but we can create beautiful machines that can go there and learn things that are so important to us."
The telescope is the culmination of decades of work from about 10,000 people helping the effort, and helping young people understand the scope of this work is part of what the McAuliffe Center offers through offering programs that simulate space missions and expanding access to STEM education.
“Sometimes our goal is to get people to be both inspired and interested in STEM careers,” Porro said. “But even if they’re not interested in this kind of career, to appreciate what kinds of intense collaborative work goes into this. This is not science fiction, this is reality — and it’s better than science fiction.”
This article originally appeared on MetroWest Daily News: Webb telescope launch: What it means to the Christa McAuliffe Center
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