NASA’s James Webb Telescope has been equipped with infrared sensors, a massive primary mirror with a diameter of 21 feet and other scientific tools that are particularly well suited to imaging, perhaps, the earliest galaxies which were formed billions of years ago, or analyzing the atmospheres of exoplanets.
However, the technology that can be used to study the makeup of impossibly distant alien worlds can also be used to study those closer to home, such as a nearby ice giant that has only been visited once by human spacecraft (Voyager 2, in 1986).
“It’s like [Webb] was designed to study Uranus’s atmosphere — it’s fabulous,” Heidi Hammel, an interdisciplinary scientist on the James Webb Space Telescope project, tells Inverse. “I used to tease my extra-galactic colleagues, ‘Thank you so much for building this camera designed to do Uranus work!”
Uranus isn’t the only one. About 7% of the observing time in Webb’s first year is devoted to Solar System science, with 22 proposals from the world’s science community to train Webb on everything from asteroids to Jovian cloud tops.
Hammel, an interdisciplinary scientist who has worked with Webb since the early 2000s, has 100 hours of guaranteed observing time, and she plans to take advantage of it.
What Webb Can Observe In Our Solar System?
Webb will be stationed in an orbit around Lagrangian Point 2, around 1 million miles from Earth, and will orbit the Sun in a steady position relative to our planet.
Heat from the Sun or the Earth might blind Webb’s incredibly sensitive infrared equipment, so this deep-space perch is critical to its operations. Webb will face us and our stars at all times, protected by a tennis court-sized sunshield.
1. How Webb Will See Mars?
“‘Why would you look at Mars? ‘ people ask. ‘Didn’t we send a hundred thousand spacecraft there?’ According to Hammel, “We have,” says the narrator. However, Hubble has been quite effective in studying Mars, and Webb will be as well.”
Webb will have better spatial resolution than Hubble for viewing Mars because of its larger primary mirror, but Hammel points out that Hubble was primarily a visible spectrum instrument.
Webb really shines in the infrared, especially infrared spectroscopy, which can help scientists decipher the chemical composition of faraway objects.
“We’ll be able to map out surface attributes of Mars throughout the day and at night,” Hammel says, referring to dust and water clouds, as well as organics like methane.
According to her, methane levels on Mars appear to vary from measurement to measurement, and Webb spectroscopy should determine whether methane levels vary throughout the entire planet over time, or if methane levels vary among regions on the Red Planet.
2. How Webb Will Track Asteroids?
If we look at some of the Hubble Images, you’ll notice strange arcs across the image, similar to strange scratches on a real photograph left in a junk drawer for too long and subjected to tossed keys and coins.
“All of those weird arcs are asteroids that have photobombed this picture of galaxies,” Hammel says. But the unwanted noise for Hubble will be data for Hammel and other Solar System scientists with Webb, “And although we will not resolve pictures of asteroids, we will be able to get spectroscopy of the asteroids,” she says.
Planetary scientists are interested in asteroids because they provide knowledge about the early days of our Solar System, providing glimpses of the same rocky components that once agglutinated to build Earth and the other rocky planets. Scientists have used ground-based spectrographs to study asteroids in order to better understand their composition.
Is There Any Catch?
Since most asteroids’ spectra are almost identical, with the exception of a region of the spectra that Hammel describes as “completely hidden from the earth.” A common problem in Solar System spectroscopy is that the spectral bands of interest for a distant object match the spectra of something in Earth’s atmosphere, such as water vapor, resulting in gaps in the spectra of your distant object.
Only a few windows of light make it to the ground, explains Hammel. “If you want to view what’s inside those barred windows, you’ll have to go to space.”
How Can Webb Help?
Using comprehensive spectra to pinpoint the temperature and pressure at the time each asteroid formed, astronomers will be able to differentiate asteroids like never before, allowing them to differentiate asteroids like never before.
3. Webb’s Crafty View of Jupiter And Saturn
When Hammel and her colleagues turn their attention to big planets, space-based infrared spectroscopy will come into work.
While Webb will aid scientists in better understanding some structural features of Jupiter and Saturn’s atmospheres, Hammel is especially eager to learn more about the chemistry of the spectacular gas giants, notably their color chemistry.
“We’re going to look at the Great Red Spot and find what the chromophore is that gives it its red color,” Hamel explains.
Jupiter and Saturn, on the other hand, are big planets that are relatively close to our Sun and thus highly brilliant. Webb won’t even look at them without some technical solutions, according to Hammel.
“Remember, these detectors are meant to detect the universe’s tiniest galaxies,” she explains. “To look at incredibly bright things, we have to utilize unique methods, such as special wavelengths that we know won’t saturate the detectors.”
NASA’s Europa Clipper mission is set to launch in 2024 and arrive at Jupiter’s moon Europa in 2030 to conduct spectroscopy.
4. Webb Looking At Europa’s Icy Moons
But why should you wait? Hammel plans to utilize Webb’s spectrometer to try to describe the composition of what are thought to be water jets erupting from Europa, as well as comparable plumes of water seen by the Cassini mission exiting the south pole of Saturn’s moon Enceladus.
Both Moons are thought to have subterranean global oceans that are in contact with rocks and minerals and are warmed by geologic action, which could be the ingredients for alien aquatic life.
“We’re going to try to put our beam, our detector, on the area where those plumes should be,” Hammel explains. “It’s a gamble.” Not risky, but potentially hazardous to the spaceship. It’s risky because we can miss anything.”
But, she claims, that is the appeal of working as an interdisciplinary scientist with a set schedule.
“Potentially risky observations might not pass a conventional time allocation committee,” Hammel explains, “but that’s why I’m doing it – I have guaranteed time and no one can say no.” That’s one of the advantages of having guaranteed time, and that’s also why they give it to us.”
Other threads of Saturnian science left by the Cassini mission will be picked up by Hammel and other scientists, including explorations of Saturn’s largest moon, Titan, thanks to Webb.
According to Hammel, it’s obscured by a photochemical haze. “It’s a dense atmosphere, yet infrared wavelengths can pierce through it and reveal surface detail.”
It’s covered in a photochemical haze, according to Hammel. “It’s a dense atmosphere, but the beauty of infrared wavelengths is that they can pierce that haze and provide surface detail.”
Through the smog, Webb will allow scientists to study the current dunes and hydrocarbon lakes on Titan, as well as track their evolution over time.
5. Webb and the Icy Giants
Webb’s four separate fields of view, each corresponding to different infrared wavelengths, precisely frame up the side-tilted ice giant, according to Hammel.
This will aid Hammel and other planetary scientists in better understanding Uranus’ upper atmosphere and how it interacts with lower levels that can be seen with current telescopes.
Spectroscopy will also allow researchers to investigate Uranus’ chemistry, specifically the existence of hydrocarbons.
“This is like a gold mine for us to be able to map these hydrocarbons out on the surface and figure out what’s driving them and where they come from in the atmosphere,” Hammel adds.
Neptune is a comparable aim, with Webb allowing scientists to analyze the planet’s atmospheric structure as well as how winds, temperature, and clouds relate to its chemistry.
6. Webb Tracing The Kuiper Belt
Using the Webb for local planetary science makes more sense as you get out to the icy, far reaches of the Solar System. Pluto, Eris, and Makemake are dwarf planets that are extremely far away and extremely cold, and scientists are eager to learn more about them.
Pluto, Eris, Makemake, and other Kuiper belt objects are so small, frigid, and far away that they’ve remained virtually unchanged since the Solar system’s inception, according to Noemi Pinilla-Alonso of the Florida Space Institute.
Kuiper belt objects, like asteroids, preserve a record of the early Solar System, albeit a slice of the protoplanetary disc far distant from the Sun than the material that created the rocky inner planets.
Pinilla-Alonso is heading a 100-hour scan of 59 “trans-Neptunian” objects, with the goal of understanding the spectrum of differences in these distant items and feeding that information into models of the Solar System’s genesis and evolution.
“What we’re aiming for,” she explains, “is to have a decent representation of the diversity in the trans-Neptunian belt so that we can answer questions about the entire population of frozen bodies in the solar system, not just a few individual objects.”
7. Webb and Discovery of The Comets
Comets are a hybrid of trans-Neptunian objects and asteroids, descending from the frigid depths of the solar system and traveling through the inner solar system before returning to the outer solar system on their long, elliptical orbits.
They’re also potential targets for Webb, who can employ spectroscopy to dissect their structure and chemical composition once more.
“We have a programme that is designed to track comets in general; we call them, target of opportunity programmes,” she says.
“There’s already a programme approved to conduct that job if another interstellar object passes by like Oumuamua,” Hammel explains. “We’re ready if Jupiter has another impact.”