An exoplanet is losing its atmosphere – scientists make an extremely rare observation

Earth’s atmosphere is a protective shield, but not all planets are so stable. An exoplanet shows what it’s like to lose an atmosphere.

MUNICH – Earth’s atmosphere serves as a life-supporting shield for our planet, largely deflecting harmful radiation and space objects approaching our planet. Without them, Earth would be a hostile place where survival would be impossible. Earth’s atmosphere appears to be remarkably stable, which is not true of all planets.

A team of researchers from the University of California and the University of Texas used the Hobby-Eberly Telescope to observe an exoplanet 900 million light-years away that is losing its atmosphere to the universe. This is the planet HAT-P-32b, which is called the hot Jupiter. Scientists have found that large amounts of helium and hydrogen are leaking from the atmosphere of an exoplanet, unlike the stable atmosphere of Earth.

An exoplanet loses its atmosphere to space

Specifically, to understand where gas is headed in the atmosphere, the research team studied the orbit of an exoplanet, Zhoujian Zhang, the lead scientist on this study, told Science Gateway. eos.org to explain. This means that the research team not only collected data from the planet when it was directly in front of its parent star, but also from the other three sides. So far, scientists have observed only one side of the star. “It’s rare for humans to cover the entire tropical period,” Zhang said.

In order to accurately locate escaping gases, it is essential to have a bird’s-eye view. “If we focus only on transiting the planet, we miss the opportunity to determine whether the planet’s escape atmosphere is expanding.” The data confirms that not only is the gas escaping from the atmosphere, but that it is spreading out into space much more than previously thought.

The flowing atmosphere leaves two paths

The gas leaves a kind of tail. This phenomenon is already known from other exoplanets, but hot Jupiter has two of them, one in front of the planet and one behind it. “It’s something very special,” said Zhang, who partied with his team in June. Science advances reported the new findings in a study. The two tails extend over six million kilometers.

Scientists also studied the velocity of the gas. More than a trillion kilograms of helium is ejected from the planet every second. For comparison: on Earth, about 50 grams of helium per second leave the Earth’s atmosphere. However, there are projects aimed at protecting the atmosphere of our Earth. Despite its huge mass, it will take more than a billion years for an exoplanet to completely lose its atmosphere.

The planet’s star dies before it can completely escape the atmosphere

However, this is unlikely to happen because the planet’s star would likely die before then. According to the scientist, the speed with which the gas escapes is “longer than the life speed of the star.” HAT-P-32b is an interesting example of how a planet can lose its atmosphere. Zhang said the findings could provide another answer to a long-standing scientific mystery.

Machine assistance was used in this editorial article. The article was carefully screened by editor Tanya Banner before it was published.