Will James Webb Telescope Be Able To See Exoplanets?

The James Webb Space Telescope (JWST) will be focusing the largest, most powerful set of mirrors and instruments ever sent into space on some of the most distant and fascinating targets in the universe, including the very first stars and galaxies to form in our universe, as well as exoplanets.

It will look for more than just distant galaxies but also at exoplanets as well as other possible planets in our own Solar System.

Can JWST Really Observe Exoplanets?

JWST isn’t really an exoplanet hunter, but its 6.5-meter primary mirror and infrared spectroscopy sensors make it ideal for peering closer than ever before at these far-off worlds. Telling us what they’re constructed of and, perhaps, if their atmospheres contain evidence of life.

Nikole Lewis, a Cornell astrophysicist, says she hopes to use some of her JWST observing time to do a “deep field” examination of WASP-17b. It’s a 1,000-light-year-distance “hot Jupiter” exoplanet.

“We’ll spend 80 hours looking at a single planet in all directions using a broad range of instruments,” Lewis tells Inverse. “This will allow us to start to understand what the different parts of the planet look like.”

“We’re going to be able to truly build a 3-D picture of what this specific hot Jupiter WASP-17b looks like” by combining temperature, cloud structure, and atmospheric chemical information, she says.

And how might such an exoplanet appear? Surprisingly, it will appear to be nothing like anything we’ve seen before. It’s a little difficult, but the results could change how we think about our place in the cosmos.

Related: Full Details: How Does Webb Telescope See The Universe?

What Will Exoplanets Look Like To JWST?

“To be honest, we’re not going to obtain gorgeous photographs of exoplanets,” Lewis admits. JWST is large and powerful, with the ability to observe billions of years in the past, but resolving a distant exoplanet next to its star so that it looks like a Hubble or Voyager image of a planet in our Solar System is still beyond its capabilities.

Exoplanets will be visible directly, according to Lewis, at least the larger ones, but they will show as “simply one bright dot.”

Don’t be dissatisfied. That dot is only the start. JWST will aid in the construction of a more sophisticated image of distant exoplanets over time by mapping them in greater detail than ever before and looking at wavelengths that have hitherto been overlooked.

“We think of planets as they seem in optics because of the light reflected off of them when we gaze at them,” Lewis explains.

“However, if you truly want to know what makes them tick, you should look at them in the infrared,” as if you want to know if their atmospheres contain organic molecules.

Other Telescopes And Their Significance

The Hubble Space Telescope has accomplished incredible astronomy, but it only sees in the optical, UV, and near-infrared wavelengths.

The now-dead Spitzer Space Telescope was tuned to the infrared, but it was discontinued in 2020, and while it did wonderful planetary astronomy, it was never meant for such a task, according to Lewis.

There are also ground-based telescopes that can be seen in the infrared, but because of the filtering effects of the Earth’s atmosphere, certain wavelengths are inaccessible to them.

Overall, Lewis says, “We were able to detect chemical fingerprints in the atmosphere” of exoplanets, “but in virtually all cases, we treat the atmosphere as being uniform, homogeneous, and basically treating it as a one-dimensional object.”

Webb And Its Many Functions

Webb, which is based in space and tailored for a wide range of infrared wavelengths, will offer data scientists with the tools they need to develop fully multi-dimensional models of exoplanets. To comprehend the structure of their atmospheres and the elements that make up their composition.

Lewis explains, “We’ll be able to look at signatures from things like carbon dioxide, carbon monoxide, methane, and all sorts of fascinating species.” “We can begin to understand what the globe looks like in two and three dimensions as opposed to that one-dimensional picture.”

What Will Our Solar System Look Like To JWST?

While Webb’s ability to investigate the universe’s farthest objects deservedly draws a lot of interest and excitement, the space telescope will also spend a lot of time staring closely at objects closer to home.

Heidi Hammel, an interdisciplinary scientist who has worked with Webb since the early 2000s, will use her observing time to look at just about everything visible outside the orbit of the Moon in our Solar System, from Mars to asteroids, the outer planets, and even the strange frigid worlds of the Kuiper belt.

It’s possible that she’s most thrilled about seeing Uranus. The ringed and tilted ice giant planet was only visited once by Voyager 2 in 1986, and it just so happens that it revolves at the perfect distance for Webb’s field of vision. We’ll get some fantastic shots of Uranus with Webb, though they’ll be in infrared, of course.

Uranus Through Webb’s VLT

She alludes to a set of photos of Uranus obtained by Hubble, the Keck Observatory, and the European Very Large Telescope in explaining what Uranus would look like through Webb (VLT).

The blue and pinkish cloud tops are apparent in Hubble and Keck’s optical and near-infrared views, but the VLTs mid-infrared images look like hazy, blunted Eyes of Sauron, or a lump of hot coal at the back of a furnace.

“The image quality on Webb will be better,” Hammel predicts. “We’ll be able to tighten up these images so they don’t look so speckled,” says the researcher.

How Would Webb Help To Observe Uranus?

Hammel and other planetary scientists will be able to better grasp how Uranus’ upper and lower atmospheres interact thanks to Webb. They will be able to map the planet’s chemical makeup like never before thanks to Webb’s spectrometer.

“Where does the methane come from?” “Where does ethane come from?” you might wonder. According to Hammel. “We’ll be able to figure out the links and tease out this chemistry as a function of altitude.”


It’s no coincidence that scientists studying distant exoplanets and planets in our own backyard are all fascinated by their targets’ spectra and chemical composition.

Such observations don’t often produce visually striking photos that can be slapped on a poster like many Hubble photographs, but they can help scientists build a broader, more detailed conceptual understanding of how all planets and solar systems, including our own, behave over time.

According to Lewis, scientists spend a lot of effort attempting to figure out how we got here.

How did our solar system come into being? What happened to make Earth the sole habitable planet in the Solar System?

“But, you know, we’ve only ever had a sample of eight things to compare to, right?” And now we’ll have a sampling of 300 to 400 items,” she explains. “This allows us to put our models of planet physics and chemistry to the test.”

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