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First Map of an Extrasolar Planet
jiawen writes "Data from the Spitzer Space Telescope has been used by researchers to make the first-ever map of an extrasolar planet. It's a weather map, more precisely, showing temperature variations over the surface of a Hot Jupiter. It really is hot: even the coldest regions are about 1200 degrees F."
The only real temperature is Kelvin (which admittetly is based on Celcius which makes a lot more sense than the screwed-up Fahrenheit scale imho :)
1 200 degrees Fahrenheit = 922.038889 kelvin
Well, if you'd bother to read TFA you would find out: 930 degrees Celsius.
You can read a preprint of the published paper for free. (The published version is here, but full text access requires a Nature subscription.)
http://www.google.com/search?q=1200F+in+C
1200 degrees Fahrenheit = 648.888889 degrees Celsius
The warmest spot is 927 C, on the equivalent of Jupiter's Great Red Spot, and the coolest region is 'only' 649 C.
Minimum 973 K +/- 33 K
Maximum 1211 K +/- 11 K
That's 1751 +/-59 R and 2171 +/-20 R, for you non SI types. Subtract 459 degrees to get Fahrenheit.
The Wikipedia page on HD 189733B has some useful info.
Oh, one small correction. We'd be able to get continuous maps. In other words, you'd be able to see temperature (and atmosphere composition) changes over time.
(At that point, something like SETI would get potentially much less of an intragalactic lottery and be much more interesting.)
I honestly don't know what resolution the NASA folks are working at, but the image presented is almost certainly some form of interpolation from available data, as even a super-Jovian planet is far too small to get more than a pixel or two resolution at any distance. I don't quite know what they're calculating, rather than directly observing, but there is simply no way they're getting that kind of resolution with direct measurement. Not of a planet.
There's nothing wrong with mathematical techniques, and if they're as good as they seem to be, then obviously the square kilometer array will be able to resolve Earth-sized planets at greater resolution than initially expected. Which is good, so long as the methods applied are valid.
(Let's face it - if anyone quibbles with these results, who do you think NASA would send over there to personally check? The person getting fame and glory for the organisation, or the person who is spoiling the party?)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
but seriously. It orbits very close to its sun so is anyone surprised the damn thing is really hot?
The interesting science is how the temperature is distributed, not that it is really hot. The planet is almost certainly tidally locked, so one side faces the star all the time. However, the hottest part of the planet is not at the "high noon" position on the "surface" (which for some reason is what the article calls the cloud-tops).
The highest temperature region is about 30 degrees (angle, not temperature!) away from high noon. This, plus the relatively small temperature difference between the light hemisphere and dark hemisphere tell us that the planetary atmosphere is subject to extremely high winds, which are distributing the heat.
This is a fascinating way of probing the dynamics of planetary atmospheres under extreme conditions.
Blasphemy is a human right. Blasphemophobia kills.
As a matter of fact, it seems we still don't know for dead certain what Fahrenheit's reasoning behind his choices were. We've got some pretty good guesses, but I tried to do some research on this when another person asked me once, and I couldn't find any authoratative answers. Between Wikipedia and several assorted websites hosted on university domains that appeared to have some signs of authenticity, I came up with over half a dozen theories. I guess a lot got lost in the nearly 300 years since he came up with it.
I think the two best theories are:
1.) He set zero as the freezing point of salt-brine, the same as the Romer scale, one of the first standardized thermometry scales. He then chose a "semi-circle" of separation between the freezing and boiling points of normal water...180 degrees...to determine the step size.
2.) He just picked 0 as the freezing point of brine and 100 as human body temperature, but his measurements are a little off. The scale was later recalibrated to make 32 and 212 degrees key points. Very simple and it invokes two of the most interesting temperatures of his day (the lowest they could measure a liquid, and body temperature).
If you read a brief biography of Fahrenheit's day, you'll find he was the equivalent of a modern uber-haxor. He dropped out of an apprenticeship (becoming a fugitive in the process) and blew most of his time and money playing around in the new-fangled field of thermometry. Can you imagine the message board arguments he must've gotten in about Florence thermometers vs Venice Thermometers? Forget about kernels...we're talking liquid columns here!