An emerging branch of science known as exometeorology is offering remarkable insights into the conditions found on some of the more extreme planets in the galaxy — including the weird and mind-boggingly massive weather patterns experienced on a hot Jupiter that's 385 light years from Earth.
Hot Jupiters are those exotic class of extrasolar planets that are very similar in size and composition to Jupiter — but these massive gas giants orbit around their parent stars at ridiculously close distances. They’re located anywhere from 0.015 to 0.5 AU from their suns (1 AU = distance from Earth to the Sun).
Needless to say, the surface temperatures of hot Jupiters are extreme, hence the name. And to make things even more interesting, these planets are tidally locked; they all feature a daylight side that’s perpetually facing the sun.
Looking to predict the kind of weather experienced on these planets, Nikole Lewis of MIT recently conducted an analysis of the hot Jupiter HAT-P-2b — a planet in an eccentric orbit around its sun (it only takes 5 days or so to complete one orbit). She put together a kind of exoplanetary weather map using a technique called SPARC/MITgcm that was developed by Nick Cowan of Northwestern University.
Because these planets are tidally locked, astronomers are able to observe their various phases, like crescent, gibbous, and full. Then, by measuring the infrared brightness of the planet during the course of its different phases, they’re able to make a rudimentary map of temperature found at the various longitudes.
Which is nothing short of incredible when considering just how far these planets are from Earth.
Using this technique, Lewis concluded that HAT-P-2b’s star-facing side features a daytime temperature of 2,400 Kelvin (2,127 degrees Celsius). The night-facing side, on the other hand, experiences a temperature of 1,200 K (927 degrees Celsius). So even at night, this planet is ten times hotter than Jupiter.
The 1,000 degree difference between the two sides is extreme — no doubt. This atmospheric dynamic results in vicious winds that howl across the surface at thousands of miles per hour. Yes, thousands.
By using Jupiter as a guide for the models, Lewis and her colleagues imagined what would happen to it if its surface temperature was dramatically increased and the rate of its rotation greatly diminished. The result, say the researchers, were supersized weather patterns — including a Great Red Spot that was a quarter of the size of the planet.
Interestingly, regular clouds of water and methane can’t form in such hot environments, leading the researchers to speculate that hot Jupiters have clouds made of silicate — essentially clouds of rock and dust.
You can check out the study here.