Artist’s concept of a Hycean planet, with a global ocean and hydrogen atmosphere. Image via Amanda Smith/ University of Cambridge.
Is there life beyond Earth? It seems extremely probable, although we still don’t have the hard evidence. But astronomers said on August 26, 2021, that they’ve identified a new class of exoplanets that are a big step forward in the search for life. They’re calling them Hycean worlds, from the words hydrogen and ocean. Planet-wide oceans and hydrogen-rich atmospheres might cover these worlds. And yet, the researchers said, they might be habitable.
Researchers from the University of Cambridge led this intriguing research. The peer-reviewed Astrophysical Journal published it on August 26.
Hycean planets: Like Earth but different
According to the researchers, Hycean worlds could greatly accelerate the search for life elsewhere. In some ways they are reminiscent of Earth, largely or even completely covered by oceans. Yet they are also uniquely alien: up to 2.6 times the diameter of Earth, with temperatures up to 200 degrees C (about 400 degrees F) and thick hydrogen atmospheres. This places them somewhere between Earth and giant planets like Neptune or Uranus.
Indeed, many such worlds in this size range are already known to ...