110 light-years from our home, a planet with mass eight times greater than Earth orbits in the habitable zone of its star. K2-18b lies in the constellation Leo and is the first discovery of its kind: a planet with water vapor inside the habitable zone.
Astronomers from the Université de Montréal published a paper announcing their discovery on September 10, and it’s waiting peer review. A day later, astronomers in the United Kingdom at the University College London published a paper in the same Nature Astronomy magazine. Does competitive rivalry between astronomers lead to star wars?
They used data from NASA’s Hubble Space Telescope and the Spitzer Space Telescope to analyze how the color of the star’s light changed as it filtered through the planet’s atmosphere. What they saw convinced researchers there was evidence of water vapor condensing into liquid water. It’s a significant discovery, being the only planet (other than the Earth of course) to date that shows evidence of water changing states between liquid and vapor.
It’s no Earth, but what could ever replace our planet? Literally nothing. It differs from Earth in a number of ways. First, its star is a highly active red dwarf, throwing off intense levels of ultra-violet radiation. Red dwarfs are small stars and K2-18b has to orbit much closer for it to reside in the star’s habitable zone. Much like our Moon, it may by tidally locked, showing only one face to the star in its 33-day orbit. The larger mass of the planet means its gravity is much higher.
By comparison, it’s a larger, highly irradiated, fast orbiting planet with evidence of evaporation and condensation. With this new find, we can expect more researchers to turn their attention to this distant, singular planet, K2-18b.
I was reading this article on the NASA website. NASA is an organization that I respect a great deal. Many innovations are developed at this institution. However, I was bothered by the intentionally misleading headline and the video embedded in the article. In case there is some confusion I’d like to point out that Hubble is an inanimate object, it did not discover anything. The discovery was made by astronomers in the United Kingdom and a competing team from the Université de Montréal. The planet was originally identified in 2015 by NASA’s Kepler space telescope and the discovery of water vapor used Hubble data.
If nothing else, it’s an interesting study in framing. NASA is claiming a significant stake in the study by using misleading language. You can argue up and down that the discovery wouldn’t be possible without NASA instrumentation, which is true, but Hubble still isn’t a researcher. So, why use language to claim ownership of a discovery that isn’t your own? I’ll leave that question open for you to ponder.