Exoplanet hunters found a planet with flowing volcanoes.

Consider this: The other half of the world is always dark.

Researchers are intrigued by how these harsh circumstances may potentially create the planet’s atmosphere. Astronomers may be close to finding an Earth-like planet beyond the solar system with an atmosphere.

NASA announced a good contender last month. Researchers detected another exoplanet, LP 791-18 D. The interesting world is inside a host star’s habitable zone (opens in a new tab), where “it is not too hot and not too cold for liquid water to exist on the surface of surrounding planets.”

“The day side would probably be too hot for liquid water to exist on the surface,” said astronomer Björn Benneke, who oversaw the study. “But the amount of volcanic activity we suspect occurs all over the planet could sustain an atmosphere, which may allow water to condense on the night side.”

Why do volcanoes affect habitability?

Planetary scientists think volcanic activity is essential for life. Volcanic eruptions provide gasses to the atmosphere and help planets maintain reasonable temperatures.

NASA jokingly calls Earth’s atmosphere its “security blanket(opens in a new tab)” because without it, life on Earth would not exist. This cocoon keeps oxygen in the air, filters out harmful ultraviolet radiation from the sun, and maintains the pressure for liquid water on the planet’s surface, keeping the Earth warm and liveable.

This temperate exoplanet orbits a tiny red dwarf star 90 light years distant in the southern constellation Crater.

Nature reported the discovery. Astronomers utilized data from NASA’s TESS and Spitzer Space Telescope, which retired in 2020, together with other ground-based observatories.

NASA previously discovered two exoplanets, B and C, circling the same star. C, the outer planet, is 2.5 times Earth’s size and seven times its mass.

C and the recently found D orbit the star close together. D’s path around the star becomes circular due to C’s tremendous gravity. If the exoplanet behaves like Jupiter’s moon Io, its distorted orbit would heat the planet’s interior, generating countless volcanic outbursts. The sun’s most volcanic planet is Io.

The paper’s co-author, Caltech astronomer Jessie Christiansen, said one of astrobiology’s central questions is whether geological activity like plate tectonics and volcanoes is necessary for life to arise.

“In addition to potentially providing an atmosphere, these processes could churn up materials that would otherwise sink down and get trapped in the crust, including those we think are important for life, like carbon,” she added.

Webb analyzes atmospheres.

The James Webb Space Telescope, the world’s leading infrared telescope, will be used to analyze the exoplanet’s atmosphere. Water and methane—essential elements for life—could indicate habitability or biological activity.

Transmission spectroscopy is possible with Webb. Planets’ atmospheres filter starlight as they cross their host stars. Astronomers may determine an atmosphere’s chemical makeup by breaking the star’s light into its fundamental parts—a rainbow—to see which light segments are missing.

Scientists have permission to investigate C, its gigantic neighbor.

Ian Crossfield, a University of Kansas astronomer and research co-author, believes it’s too early to speculate on the exoplanet’s volcanic activity or habitability. He’s curious.

“People study Jupiter still,” he remarked (opens in a new tab), “but they don’t do it because they think there are aliens living there.”