It’s been almost four years since the James Webb Space Telescope (JWST) launched, ushering in a new era of advanced astronomical research. “This is a telescope that everyone wants to use — it’s so versatile, so powerful,” says Michael Maseda, an assistant professor of astronomy who was part of the organization that developed the JWST’s initial science program. Maseda, who studies galaxies, and his departmental colleague Thomas Beatty, an assistant professor of astronomy who studies exoplanets, are excited about how the JWST has advanced research.
1. Astronomer models of the early universe were largely correct.
“The JWST is able to see further away — able to see further back in time,” explains Maseda. The early universe — the one that appeared immediately after the Big Bang — was composed of only hydrogen and helium. As stars in those galaxies died, additional elements (think oxygen, carbon and nitrogen) were introduced. To astronomers, those elements act like a clock, giving clues to origin stories.
2. The calibrations researchers have used to measure the amount of oxygen in our galaxy don’t work in distant galaxies.
Maseda and other researchers established that younger galaxies are marked by the presence of elements beyond hydrogen and helium — the twin building blocks of the oldest galaxies. But a few of the observations they’re receiving aren’t matching up with the calibrations and models they’ve developed to predict how quickly a distant galaxy is evolving, requiring some fine tuning. “We need to revise it,” says Maseda.
3. Black holes in distant galaxies are bigger than astronomers expected.
Most galaxies have a massive black hole at their centers, including the ones that are farthest away from us. Those black holes don’t emit light, but the stars and gasses that circle around them emit plenty. “In some cases, there can be more light coming from that than there is from the rest of the galaxy,” says Maseda. And astronomers still don’t know how these large black holes formed and became so sizable — sometimes millions of times the mass of our sun.
4. The composition of an exoplanet’s atmospheres is actually pretty complicated.
Beatty measures the atmospheric composition of exoplanets, which are planets that orbit stars outside our solar system. “It’s been surprising how rich that chemistry is in their atmospheres,” he says. Beatty worked as an instrument scientist on the JWST before joining the UW–Madison faculty. He recently presented research on a sub-Neptune exoplanet some 96 light years away from our solar system that could offer important clues as to how it formed.
5. Is there life out there?
It’s the proverbial million-dollar question. “There’s an idea that you can have ‘gas dwarf’ planets that are still conducive to life,” says Beatty. Interdisciplinary collaboration has been critical in finding an answer. Beatty collaborates with colleagues through the new Wisconsin Center for Origins Research (WiCOR), a group that connects seven different scientific departments in the College of Letters & Science, to find answers.
6. Finally, a legit explanation for radius inflation.
This is the idea that many exoplanets are much bigger than researchers would expect them to be. For example, an exoplanet with a mass equal to Jupiter should theoretically be the size of Jupiter, but in several instances, researchers have discovered exoplanets that are twice that size, with their mass somehow inflated to fill the vacuum. “With the JWST observations, we were able to make a very convincing argument that this was driven by tides,” says Beatty.
