K2-18b may harbor life, scientists say after discovering dimethyl sulfide

While a mission to K2-18b remains beyond our reach—given that Voyager 1, traveling at 38,000 miles per hour, would take over two million years to get there—projects like Breakthrough Starshot aim to change the paradigm by achieving 20% of the speed of light.

While no conclusive evidence has yet been found of extraterrestrial life, scientists are seeking out worlds like K2-18b with hydrogen-rich atmospheres that astronomers believe to be covered in liquid water. And it's not just government space agencies like NASA that are avidly involved in that work.

K2-18b has long been considered the premier candidate for a "hycean planet" — an ocean world bigger than Earth with a hydrogen-rich atmosphere. Hycean planets, much like Earth, are covered in oceans and have atmospheres rich with hydrogen, an element that is essential for life.

K2-18b resides within the habitable zone of its star, making the presence of liquid water and thus life possible. Using the James Webb Space Telescope, researchers detected molecules in K2-18b's atmosphere that are associated with life on Earth.