Citizen Science #27 by Jamie Zvirzdin
Solving the Mystery of Life on a Faraway World
“Who could imagine that a little farther on in that quiet landscape I should meet and shake by the hand a man who […] had seen this Earth from where it looks like a mere point of green fire, and who had spoken face to face with a creature whose life began before our own planet was inhabitable?”
This line from “Perelandra,” C.S. Lewis’ 1943 novel and the second book of his Space Trilogy series, speaks to our endless fascination with the possibility of life beyond our home. Today, this fascination points us toward an exciting discovery: a distant planet with a rather forgettable name, K2-18b, and a story that could change how we see our place in the cosmos.
K2-18b isn’t exactly next door. At 124 light-years away, even our swiftest spacecraft would need nearly two million years to reach it. Despite this vast distance, we’re learning more about it with every passing year.
First discovered in 2015 by the Kepler Space Telescope, K2-18b quickly drew attention. It is roughly 2.6 times Earth’s diameter, making it unlike anything in our solar system—a so-called “hycean” world. Imagine a planet with a deep, global ocean beneath a huge, puffy atmosphere dominated by hydrogen and helium. It’s not unlike Lewis’ fictional world Perelandra: vast, watery, mysterious.
