Astronomers have discovered that a planet far beyond our solar system has an atmosphere with water vapor. According to British scientists, K2-18b is therefore the most suitable exoplanet to support life as we know it. The researchers describe their findings in the scientific journal Nature Astronomy .
The exoplanet, or a planet revolving around a star other than our sun, was discovered in 2015 by the Kepler space telescope. Presumably K2-18b is eight times the size of the earth. The presence of water vapor was discovered with observations from the Hubble space telescope.
The planet is in the 'livable zone', also known as the Goudlokje area, of its star. The livable zone is the distance from a star where life is possible as it occurs on earth. This is mainly because the temperature on the planet in question is moderate, so that liquid water is possible.
In addition, the planet appears to have an atmosphere and therefore there would be water, making it possible to support life.
Many discovered exoplanets are gas giants, but K2-18b may consist of stone. It is also possible that K2-18b is made of ice, which contains liquid water.
The discovery was made possible by observations from the Hubble Space Telescope. (Photo: NASA)
It is not yet possible to determine what atmosphere consists of
It is not yet possible to determine exactly what the atmosphere consists of, but it may be 50% water. To get more precise data about the planet, follow-up observations would be needed.
The future James Webb space telescope should enable more precise observations, just like the intended ARIEL satellite from the European Space Agency ESA.
See also: James Webb space telescope assembled for the first time
Planet maybe less livable by star
The planet revolves around a so-called red dwarf, a star that is considerably smaller than our sun. The temperature of the star is therefore much lower.
In astronomy there is a debate about whether living in a galaxy of a red dwarf is possible, for example because the planet has to be closer to the star because of the lower temperatures of the red dwarf.
This can cause the planet to get stuck in "synchronous rotation," as our moon has with the Earth. This means that the same side of the planet always points to the red dwarf, while it revolves around the star. This means that one half of the planet is considerably warmer than the other.
- Want to know what you missed at night? And an update on the most important news around lunch? Subscribe now to our daily newsletter!