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Scientists Are Studying K2-18b to Find Whether It Is Habitable

Scientists Are Studying K2-18b to Find Whether It Is Habitable

It was thrilling last week when scientists announced water vapor in a super-Earth’s atmosphere. However, even because the announcement came, other scientists have been cautioning that the planet – K2-18b – is probably much less like a super-Earth and more like a Mini-Neptune.
A few days ago, EarthSky reported that for the first time, water vapor had been detected within the atmosphere of a potentially habitable super-Earth exoplanet. We weren’t alone in our report. As could be anticipated, the finding received lots of attention from the media. However, it seems that the story won’t be quite as first reported and was mischaracterized to some extent.
The discovery was outlined in two different papers, the primary one published on arXiv on September 10, 2019, and the second within the peer-reviewed journal Nature Astronomy on September 11, 2019.
The papers detail the finding of water vapor within the atmosphere of K2-18b, an exoplanet within the habitable zone of its star – where temperatures might allow liquid water to exist – 110 light-years from Earth. It’s accurate that that is the first time that water vapor has been identified within the atmosphere of a smaller exoplanet (non-gas-giant) within the habitable zone of its star, however soon after the announcement, many planetary scientists critiqued how the discovery was covered in media and social media.
The water vapor detection itself is confirmed. However, there may be plenty of debate as to only what kind of planet K2-18b is, and how habitable it might be (or not). Some scientists, together with within the Nature Astronomy paper, have referred to the planet as a super-Earth. A super-Earth is more massive than Earth however smaller than Neptune – typically up to about a most of twice the size of Earth – and lots of have been found already. Most are thought to be rocky, like Earth. However, there’s a transition point – starting about 1.6 to 2 times Earth’s radius – where a planet can turn into a mini-gas-giant, or a Mini-Neptune as they’re usually called. They are larger than super-Earths, however still smaller than Neptune.
Most scientists now consider K2-18b to be a Mini-Neptune, not a super-Earth, with a deep atmosphere of hydrogen or helium, and probably no solid surface at all. K2-18b has a radius of about 2.7 times more than Earth, and a mass about nine times that of Earth. While some scientists would still consider that to be a possible super-Earth, most, it appears, would classify it as a Mini-Neptune. All of this is usually a bit confusing.

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Dorothy Peterson

Dorothy works as the senior editor of the science blog. She is a girl full of life. She is a friend of all and is loved by everyone in the organization. In such a young age she is doing her job in a very professional and responsible way. Most of the time she seats in the library going through piles of books to search out topics for her articles. It has been 3 years since she has been working in our organization