Unlocking the mysteries of lava worlds: A guiding light for the James Webb Space Telescope

What are these lava worlds?

Unlike the eight planets in our solar system, these are rostral exoplanets—significantly larger than Earth—and orbit so close to their parent star that they are shrouded in lava-filled oceans.

And then there are the hot Jupiters, colossal gas giants that reside more relative to their parent star than Mercury does to the sun.

Zilinskas states, "We know little about these distant worlds. Some features astronomers can estimate based on mass, radius, and distance from the parent star. But that doesn't give a complete picture."

To gain deeper insights into their atmospheres, astronomers employ spectroscopy, a method of measuring light from the parent star as it passes through the exoplanet's atmosphere, creating a unique color-based 'fingerprint' indicative of the substances present in the atmosphere.

Unraveling these fingerprints, however, is a challenging feat. This is where Zilinskas uses mathematical models to predict how specific properties translate into observations.

"I calculate what astronomers might observe," he says. "The purpose of my simulations is to tell astronomers what to look for and what that can tell them about exoplanets."

Zilinskas has zeroed in on lava worlds during his Ph.D. research, particularly their observation with the James Webb Space Telescope, launched in late 2021.

"We think silicate-rich gases can evaporate from lava oceans to form a thin, tenuous atmosphere," he explains. "We are trying to predict the chemical composition and important properties of those atmospheres, such as temperature changes, and how that affects the light spectrum."

Zilinskas employed one-dimensional models that assume the most remarkable chemical changes occur vertically—from top to bottom—rather than horizontally. "One-dimensional models allow us to investigate many different possible atmospheric compositions," he clarifies.

His simulations suggested that the James Webb Space Telescope can observe the atmospheres of lava worlds—if they exist. "It also showed what a big step forward this space telescope is," adds Zilinskas.

As the telescope continues its exploration of exoplanets, including the captivating lava worlds, Zilinskas hopes his Ph.D. research will pave the way for future observations of these otherworldly atmospheres. So, buckle up, space fans, as we delve deeper into the secrets of the cosmos!