We live in a golden age of planet discovery.
Astronomers are using modern telescopes, both on Earth and in space, to find or zoom in on planets well beyond our solar system, called exoplanets. Some are super-Earths. Some are Earth-sized. Some are gas giants. And beyond. All these planetary finds, of which there are now over 5,700 confirmed discoveries, help us grasp what's out there — and reveal whether our own solar system is a typical, or atypical, place in the cosmos.
Using the powerful James Webb Space Telescope, orbiting 1 million miles from Earth, scientists peered closely at the planet AF Lep b, an extremely young gas planet at just 23 million years old. (Earth is some 4.5 billion years old.) But they didn't have much time. The exoplanet's orbit is bringing it near its star, whose brightness will make it impossible to view AF Lep b for over a decade.
"AF Lep b is right at the inner edge of being detectable," Kyle Franson, an astronomer and graduate student at The University of Texas at Austin, said in a statement. "Even though it is extraordinarily sensitive, JWST is smaller than our largest telescopes on the ground."
In a hurry, the research team applied for "Director’s Discretionary Time" from the Space Telescope Science Institute in Baltimore, which manages the Webb telescope. They got it.
The imagery was also made possible by Webb's coronagraph, which blocks most of the overpowering light from a nearby star, allowing for the observation of a much fainter target (like a planet). In this case, the coronagraph blocked 90 percent of the star's light.
The view below shows a zoomed-in view of AF Lep b, located 88 light-years away. It's the light blue-colored object to the left of the yellow star symbol (the actual star has been blocked by Webb's coronagraph). Yet just that tiny amount of planetary light provides astronomers a wealth of information, which was recently published in the peer-reviewed science publication The Astrophysical Journal Letters.
Webb carries a host of other instruments, like a spectrograph that can detect what elements or molecules exist in a far-off world's atmosphere. The astronomers found that AF Lep b, at about three times the mass of Jupiter, has a "very active atmosphere." For instance, they detected the gas carbon monoxide. "The only way to get gas of that type into the planet’s upper atmosphere is with strong updrafts," William Balmer, a coauthor of the research at Johns Hopkins University, added.
Astronomers expect to learn bounties more about exoplanets in the coming years.
"There’s a lot more to come."
"In the big picture, these data were taken in JWST’s second year of operations. There’s a lot more to come," Brendan Bowler, an astronomer at The University of Texas at Austin and also a co-author of the study, said in a statement. "It’s not just about the planets that we know about now. It’s also about the planets that we soon discover. This is foreshadowing some of the exciting work that we will see in the coming years."
The Webb telescope's powerful abilities
The Webb telescope — a scientific collaboration between NASA, ESA, and the Canadian Space Agency — is designed to peer into the deepest cosmos and reveal new insights about the early universe. But as shown above, it's also examining intriguing planets in our galaxy, along with the planets and moons in our solar system.
Here's how Webb is achieving unparalleled feats, and likely will for decades to come:
- Giant mirror: Webb's mirror, which captures light, is over 21 feet across. That's over two-and-a-half times larger than the Hubble Space Telescope's mirror. Capturing more light allows Webb to see more distant, ancient objects. The telescope is peering at stars and galaxies that formed over 13 billion years ago, just a few hundred million years after the Big Bang. "We're going to see the very first stars and galaxies that ever formed," Jean Creighton, an astronomer and the director of the Manfred Olson Planetarium at the University of Wisconsin–Milwaukee, told Mashable in 2021.
- Infrared view: Unlike Hubble, which largely views light that's visible to us, Webb is primarily an infrared telescope, meaning it views light in the infrared spectrum. This allows us to see far more of the universe. Infrared has longer wavelengths than visible light, so the light waves more efficiently slip through cosmic clouds; the light doesn't as often collide with and get scattered by these densely packed particles. Ultimately, Webb's infrared eyesight can penetrate places Hubble can't.
"It lifts the veil," said Creighton.
- Peering into distant exoplanets: The Webb telescope carries specialized equipment called spectrographs that will revolutionize our understanding of these far-off worlds. The instruments can decipher what molecules (such as water, carbon dioxide, and methane) exist in the atmospheres of distant exoplanets — be they gas giants or smaller rocky worlds. Webb looks at exoplanets in the Milky Way galaxy. Who knows what we'll find?
"We might learn things we never thought about," Mercedes López-Morales, an exoplanet researcher and astrophysicist at the Center for Astrophysics-Harvard & Smithsonian, told Mashable in 2021.
Already, astronomers have successfully found intriguing chemical reactions on a planet 700 light-years away, and have started looking at one of the most anticipated places in the cosmos: the rocky, Earth-sized planets of the TRAPPIST solar system.
