Space is scary. Aside from the soul-crushing emptiness, the mind-bending enormity, and the general inhospitality of the place, there are all of the unknowns. We’re only a few decades into our exploration of the great beyond, and while we think we have a handle on what’s going on in the universe, we likely have no idea what’s in store in other galaxies and the farthest reaches of space. It seems like every week there's a new discovery made which challenges one or more of the assumptions we currently have about the way things work out there in physics land. Just last week, in fact, NASA astronomers announced the discovery of a planet so unlike anything we've found and so terrifying that some outlets have nicknamed it a “death planet.”
The planet lies about 350 light-years from Earth, orbiting its host star WASP-18 in the Phoenix constellation. WASP-18b is a type of planet known as a “hot Jupiter,” meaning it’s a gas giant which orbits quite close to its host star leading to extremely high temperatures. WASP-18b is also enormous, measuring about ten times the mass of our solar system’s largest planet, Jupiter. What makes WASP-18b interesting - and deadly - is its chemical composition. The planet’s atmosphere is composed almost exclusively of carbon monoxide without any indication of water, which is quite unusual. In a press release, Kyle Sheppard of NASA’s Goddard Space Flight Center says that this unique chemical composition makes this planet an astronomical oddball:
The composition of WASP-18b defies all expectations. We don’t know of any other extrasolar planet where carbon monoxide so completely dominates the upper atmosphere.
Scientists are already predicting that the discovery of this enormous, anomalous planet could revolutionize our understanding of planetary formation. WASP-18b’s searing temperatures, carbon monoxide atmosphere, and complete lack of water make it one of the least hospitable planets for life - at least by our current definition of life.
Discoveries like these make you wonder: if there is some unknown form of life on a planet like this one which is believed to be completely inhospitable, would we even be able to recognize it as life? Before the invention of the microscope, we had no idea that there was microscopic life right under our noses. Scientists have been finding microbial life here on Earth in some of the least hospitable places possible, and there might even be microbes growing on the International Space Station in the vacuum of space. Advances in space technology could someday reveal whole new possibilities of life we have never imagined. While we're calling WASP-18b a “death planet” for now, who knows what might be lurking at its core?