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wtf_nature
Sunny with a chance of lava
With the list of known extrasolar planets getting longer and longer every week, and whole new types of planets like the Hot Jupiters, it's not surprising that we eventually discover an example of something even more extreme - a Cthonian Planet named COROT-7b.
Cthonian worlds are thought to be what you get when a small gas giant orbits so close to it's parent star that all the 'normal' atmosphere of hydrogen, helium, and lighter gases boils off under the blaze of coronal mass ejections, and the like. In the case of COROT-7b, what we have left is a ball of silicate rock under twice as big as Earth, orbiting so close to it's parent star that the year is 20 hours long.
That's close enough for one side of the planet to fry at 2700 Kelvin ( well over 4000 Fahrenheit ). But because it's so close to it's star - a mere 1.26 million miles - tidal forces have almost certainly locked it - so the dark side would be a mere 288 Kelvin (59 degrees Fahrenheit). Thermochemical equilibrium calculations show that starting with those conditions, and that sort of rock, the atmosphere would be a sodium, potassium, and silicon monoxide vapour - and surprising amounts of oxygen, cracked from the rocks as they boil. Other elements such as magnesium, aluminium, calcium and iron would appear in lesser amounts.
But despite the weirdness you'd still get the same kind of weather you get on earth - different layers of atmosphere saturated with different gases, until they start to condense out and fall as rain and hail. But on COROT-7b the oceans are molten lava and the hail is in the form of red-hot pebbles. And they'd fractionate out too, so some storms would rain enstatite and rubies, and others would dump spinel and wollastonite
And on top of all that, as the red-hot winds howl around the planet from Hot Side to Dark, the entire daylight atmosphere lights like a sodium lamp, from the sodium metal vapour that makes up most of it reacting to the solar wind from COROT-7.
Not a hospitable place - but an awesome sci-fi setting.
Cthonian worlds are thought to be what you get when a small gas giant orbits so close to it's parent star that all the 'normal' atmosphere of hydrogen, helium, and lighter gases boils off under the blaze of coronal mass ejections, and the like. In the case of COROT-7b, what we have left is a ball of silicate rock under twice as big as Earth, orbiting so close to it's parent star that the year is 20 hours long.
That's close enough for one side of the planet to fry at 2700 Kelvin ( well over 4000 Fahrenheit ). But because it's so close to it's star - a mere 1.26 million miles - tidal forces have almost certainly locked it - so the dark side would be a mere 288 Kelvin (59 degrees Fahrenheit). Thermochemical equilibrium calculations show that starting with those conditions, and that sort of rock, the atmosphere would be a sodium, potassium, and silicon monoxide vapour - and surprising amounts of oxygen, cracked from the rocks as they boil. Other elements such as magnesium, aluminium, calcium and iron would appear in lesser amounts.
But despite the weirdness you'd still get the same kind of weather you get on earth - different layers of atmosphere saturated with different gases, until they start to condense out and fall as rain and hail. But on COROT-7b the oceans are molten lava and the hail is in the form of red-hot pebbles. And they'd fractionate out too, so some storms would rain enstatite and rubies, and others would dump spinel and wollastonite
And on top of all that, as the red-hot winds howl around the planet from Hot Side to Dark, the entire daylight atmosphere lights like a sodium lamp, from the sodium metal vapour that makes up most of it reacting to the solar wind from COROT-7.
Not a hospitable place - but an awesome sci-fi setting.