K2-18b is an exoplanet located approximately 124 light-years away from Earth in the constellation Leo. It was discovered in 2015 by the Kepler spacecraft and confirmed in 2019 by the Hubble Space Telescope.
K2-18b is considered a super-Earth, meaning it is larger than Earth but smaller than gas giants like Neptune. It has a radius about 2.7 times that of Earth and a mass about 8 times greater. The planet orbits its host star, K2-18, in the habitable zone, which is the region where conditions may be suitable for liquid water to exist on the planet's surface.
One of the most intriguing aspects of K2-18b is the detection of water vapor in its atmosphere. This discovery was made using the Hubble Space Telescope and has sparked interest in the planet's potential for hosting life. However, it is important to note that K2-18b is not necessarily habitable, as many other factors, such as the composition of its atmosphere and the presence of a protective magnetic field, also play a role in determining a planet's habitability.
Further studies and future missions, such as the James Webb Space Telescope, will provide more insights into the nature of K2-18b and its potential for supporting life.