[ad_1]
In their quest for life beyond Earth, astronomers who study distant exoplanets are looking for some key ingredients. For starters, a planet must be close enough to its host star to receive enough heat, but far enough away to not be boiling. Secondly, it is equally important to note the presence of water that, to our knowledge, is vital for all life.
Most exoplanet scientists are too hot or too cold, or are large balls of gas without a clear surface. K2-18b is different and Hubble Space Telescope observations suggest that it is not only at a good distance from its star but contains water vapor in its atmosphere. It's huge.
K2-18b lies in what is thought to be the habitable zone of its star, but apart from that, the world seems to be a little different from the Earth. It is a rocky planet, like ours, but it is much larger, with about eight times its mass. As a result, the planet exerts a more intense gravitational attraction.
In a new article published in Nature Astronomyresearchers explain that the light passing through the planet's atmosphere has provided clues as to what it might contain. Using data collected as early as 2016, researchers have been able to determine that the planet's atmosphere contains water vapor as well as hydrogen and helium.
Water, a reasonable temperature and an appropriate atmosphere are the three things that scientists are looking for above all in the search for potentially habitable worlds. However, there remain serious questions about K2-18b, especially if its particularly intense red dwarf star hit the planet with too much radiation to allow life to take root.
At a distance of about 110 light-years from Earth, it is closer than many sites in the night sky, but it is still too far away for us to do anything but look at it with envy. As astronomers continue to search for potentially habitable worlds, we will learn more about what it means to be truly "Earth-like", but in the meantime, K2-18b is closer than most others.
Image Source: ESA / Hubble, M. Kornmesser
[ad_2]
Source link