Large, rocky exoplanet could support life
Astronomers from the University of Cambridge say that they have found a potentially habitable exoplanet that’s twice the size of Earth.
An exoplanet is any planet beyond our solar system
The new study, which details the astronomers’ findings on exoplanet K2-18b, was published in The Astrophysical Journal Letters
Exoplanet K2-18b is 124 light-years away and has temperatures that could make it habitable, allowing liquid water to exist in its atmosphere
It is 8.6 times the mass and 2.6 times the radius of Earth, and already gained fame in 2019
Last year, two research groups claimed to have detected water vapour in the exoplanet’s hydrogen-rich atmosphere, but details about the atmosphere remain scarce
Cambridge Institute of Astronomy’s Dr. Nikku Mashusudhan, lead author of the new study, says that many exoplanets have been found to have water vapour
However, not every exoplanet that has water vapour and is in the habitable zone is actually habitable
Astronomers still have to analyze the exoplanet’s interior and atmospheric conditions
The most important factor is if liquid water is able to exist beneath the exoplanet’s atmosphere
Because exoplanet K2-18b is quite large, many had proposed that it resembled Neptune more than it does Earth
If it is more like Neptune, it might be enveloped by hydrogen and have a layer of high-pressure water
Its core would be rock and iron
If its envelope of hydrogen is too thick, that would mean its water surface would have a temperature and pressure too great to sustain life
However, the new study proves that exoplanet K2-18b isn’t enveloped by a thick layer of hydrogen
Thus, its water layer might just have the right temperature and pressure for life
The biggest takeaway from this research is that exoplanets significantly larger than Earth might have habitable conditions
The US National Aeronautics and Space Administration states that the search for exoplanets begins with an analysis of what is considered necessary on Earth
Water is the “non-negotiable”
Astronomers look for planets that have the right distance, temperature, and planetary surface where liquid water could exist
The most likely exoplanets for habitability are small and rocky, like Earth
Astronomers have confirmed the existence of over 3,200 exoplanets and observed possibly 2,400 more in the past two decades
Though these exoplanets have been found, many of them are made up of gas or ice, making them uninhabitable
Humans currently don’t have technology advanced enough to determine what exactly lies on the surface of the few Earth-like exoplanets astronomers have found
NASA has relied on space telescopes to look for Earth-sized exoplanets too far for them to see on Earth
One of these was NASA’s Kepler, which collected data in space for nine years before it was retired in 2018
NASA will soon be launching the James Webb Space Telescope, which is expected to analyze exoplanets made up mainly of gas and exoplanets larger than Earth
They also expect to launch the Wide-Field Infrared Survey Telescope or WFIRST sometime in the 2020s to analyze exoplanets’ reflected light
This would give the telescope data on the exoplanet’s water vapor, oxygen, and other conditions for habitability