K2–18b is an earth–like planet
Astronomers find water in the atmosphere of an exoplanet, located in the habitable zone of a distant star. K2-18b, the planet, is now a candidate for the human search of extra-terrestrial life. This planet was discovered in 2015 and is one of the hundreds of super-Earths. Super-Earths are planets with a mass between Earth and Neptune. Water found on planet K2-18b has once again raised the debatable question “is extraterrestrial life possible?”
Climate in K2-18b
We humans have always been curious to know whether any planet of this massive universe will be habitable. This discovery of water vapor in K2-18b’s atmosphere has opened up new avenues for the researchers.
The term ‘Habitable Zone’ refers to the region surrounding a star where temperatures are sufficiently warm for the water to exist in a liquid state. That is, this planet has an equilibrium temperature as same as our planet’s (between 0 and 40 degree Celsius). Its solar irradiance is 94% similar to what Earth receives. Water found on K2-18b Planet has once again brought in rays of hope about extraterrestrial life.
K2-18b: Size, structure, and distance
The planet is double the size of our home planet and eight times heavier. K2-18b orbits around a dim red host star, called M dwarf, within a time period of 33 days. This planet is said to be in the constellation Leo.
The planet was discovered as a part of the Kepler Space Observatory program. This planet, also known as EPIC 201912552 b revealed the molecular signature of water. Computer modeling says that 50% of the planet’s atmosphere could be water, an essential element for life.
This is the best-ever candidate for habitability with favorable temperature to support water, the existence of an atmosphere, and the presence of water.
To proceed with the findings, it is crucial to send a probe to this new place/ friend. K2-18b is 111 light-years from Earth, that is, about 650 million miles. This long distance makes it impossible to send a probe. So within ten years, with the help of modern telescopes, humans will be able to determine the presence of gases caused by life in this planet’s atmosphere.
What makes K2-18b unique?
Until now, various planets have been candidates for the habitability-search. But, each of them was not suitable for human life due to extreme heat, cold, absence of oxygen, or water. Also, some of them may be too big or small to be on this list. For instance, a planet called WASP-39b in which water vapor was found was of huge size. Therefore, it has an extreme day time temperature.
However, in the ‘new’ planet, clouds of water droplets are likely. This can even cause rain. If the results hold, K2-18b would be the first confirmed exoplanet with clouds of water vapor. Also, relatively low brightness of the planet makes it more suitable for future observations of its atmosphere.
In total, K2-18b is an ideal target for follow-up missions. The modern telescopes that research on this planet will be able to see other atmospheric gases, including ammonia, methane, carbon dioxide, and even chemical markers that suit life.
The scientific journal, Nature Astronomy has published the details of this discovery under the title Water vapour in the atmosphere of the habitable-zone eight-Earth-mass planet K2-18 b .