“Unique and extreme”: James Webb telescope detects possible alien world teeming with volcanoes

Today we know more than 5,000 exoplanets: planets outside our solar system which orbit other stars. As efforts to discover new worlds continue, we are gradually learning more about the exoplanets we have already detected: their size, what they are made of, and whether they have an atmosphere.

Our team has now provided preliminary evidence of a sulfur-a rich atmosphere on a world 1.5 times larger than Earth and located 35 light years away. If confirmed, it would be the smallest known exoplanet with an atmosphere. The potential presence of gases sulfur dioxide (SO₂) And hydrogen sulfide (H₂S) in this atmosphere, an allusion to a melted mixture or volcanic surface.

In our solar system, we have two distinct categories of planets: small rocky planets, including Earth and Mars, and gas giants like Jupiter and Saturn. However, exoplanets cover a wide spectrum of sizes. Our solar system doesn’t have a planet between Earth and Neptune in size, but it turns out it’s the most common type of planet we’ve seen around other stars in our galaxy.

Those closer to the size of Neptune are called sub-Neptune and those that are closer to the size of Earth are called super-Earths. L 98-59 d is a super-Earth, slightly larger and heavier than Earth. The composition of the atmospheres of these planets is still an open question, which we are only beginning to explore with the James Webb Space Telescope (JWST), launched in 2021.

L 98-59 d was discovered in 2019 with NASAIt is Tess Space Telescope. Most exoplanets, including L 98-59 d, have been detected using “transit method”. This measures the tiny dips in starlight as the planet passes in front of the star. This drop is more pronounced for larger planets and allows us to determine the size of a planet.

Even JWST can’t separate these tiny planets from their host stars because they orbit too close to their stars. But there is a way to “see” the planet’s atmosphere from this entangled light. When a planet passes in front of its star, some of the starlight filters through the planet’s atmosphere, hitting gas molecules or atoms present there, before reaching us on Earth.

Each gas modifies light in its own way. From the light we receive from this star system, we can deduce what the composition of this atmosphere might be. This is called transmission spectroscopya proven technique that has already been used to confirm the presence of CO₂ in the atmosphere of an exoplanet.

A photo of a volcano spewing lava

The potential detection of sulfur dioxide and hydrogen sulfide hints at a molten or volcanic surface. (Image credit: USGS Photo)

I am part of an international team of scientists who used JWST to observe a transit of L 98-59 d through the disk of its host star. We then obtained the transmission spectrum of the exoplanet atmosphere from these observations. This specter alluded to the possible presence of a atmosphere filled with sulfur dioxide and hydrogen sulfide.

This discovery is surprising because it contrasts sharply with the atmospheres of rocky planets in our own solar system, where water vapor and carbon dioxide are much more prevalent. The Earth’s atmosphere, for example, is rich in nitrogen and oxygen, with traces of water vapor. Meanwhile, Venus has a thick atmosphere dominated by carbon dioxide. Even Mars has a thin atmosphere dominated by carbon dioxide.

We then used computer models that integrate our understanding of planetary atmospheres and light from L 98-59 d to give a potential picture of the composition of this planet’s atmosphere. The absence of common gases such as carbon dioxide and the presence of SO₂ and H₂S suggest an atmosphere shaped by processes entirely different from those we experience in our solar system. This hints at unique and extreme conditions on L 98-59 d, such as a molten or volcanic surface.

Additional observations will be necessary to confirm the presence of these gases. JWST observations had already spotted signs of SO₂ on an exoplanet, but it was a gas giant, not a potentially rocky world like L 98-59 d.

A photo of Io

The distant exoplanet may share some similarities with Jupiter’s moon Io. (Image credit: NASA/JPL/University of Arizona)

Exo-volcanoes?

The potential presence of SO₂ and H₂S raises questions about their origin. An explosive possibility is volcanism caused by tidal heatinga bit like what we observe on Io, Jupiter’s moon. The gravitational pull of the host star on this planet stretches and squeezes it as it orbits. This movement can heat the center of the planet, melt its interior and produce extreme volcanic eruptions, or even oceans of magma.

Combined with its proximity to the star (a year on this planet is equivalent to seven and a half Earth days), truly hellish temperatures can be reached on the surface. If future observations confirm the presence of such an atmosphere, it would not only be the smallest exoplanet to have an atmosphere detected, but also a crucial step toward understanding the nature of these planets.

Detecting atmospheres on small, rocky planets is exceptionally difficult, because the planets are very small compared to the host stars, and also because the intense radiation from their host stars often destroys the atmosphere. These observations, while appealing, only come from a single transit. This means that instrumental noise and other factors prevent us from making statistically sound claims. Future JWST observations will be essential to confirm or refute our analysis.

L 98-59 d may not be a candidate for life as we know it, but studying its sulfurous atmosphere and potential volcanism provides valuable information about worlds surrounding other stars. Extreme worlds like these help us understand the diversity of planetary evolution across the galaxy.

This edited article is republished from The conversation under Creative Commons license. Read the original article.

Apre-salomemanzo

Apre-salomemanzo

“Unique and extreme”: James Webb telescope detects possible alien world teeming with volcanoes

Umito

Reviews | How Adityanath’s slogan could have become a call for unity among all Indians

RFK Jr. says Trump in White House will eliminate fluoride from drinking water

Here are the new guidelines to prevent strokes, the nation’s 4th biggest killer – ABC 6 News

The complexities of LPG power issues are resolved

“Unique and extreme”: James Webb telescope detects possible alien world teeming with volcanoes

Umito

You Might Also Like

Reviews | How Adityanath’s slogan could have become a call for unity among all Indians

RFK Jr. says Trump in White House will eliminate fluoride from drinking water

Here are the new guidelines to prevent strokes, the nation’s 4th biggest killer – ABC 6 News

The complexities of LPG power issues are resolved