Pluto is Much Colder Than Expected

IZ Reloaded writes "Any would be travellers to Pluto should bring extra winter gear. The new temperature on Pluto according to scientists is 43 degrees Kelvin. That's 10 degrees Kelvin colder than expected. From CNN: "Astronomers think Pluto's colder than expected temperature reading involves interactions between nitrogen ice on the planet's surface and the nitrogen gas that makes up its atmosphere...Pluto is a dynamic example of what we might call an anti-greenhouse effect...""

Comments

hmm

[autopr0n]

While scientificaly intresting, I don't think 10k really makes much of a diffrence for humans at that temprature.

Re:hmm

[Belseth]

It's interesting because it's an effect they haven't seen before. An atmosphere actually helping to cool a planet is something new and pretty amazing. It seems to act like a giant evaporative cooler. The more that's understood about the physics of known planets the more accurate the information will be that can be gleaned from distant planets. Ten degrees may not seem like much but it's an important piece of the overall puzzle. It also means that Pluto is a lot more active and more interesting than people have thought.

Re:hmm

[Vellmont]

Well, from what I know the reason that RTG generators are used is because of the extremely low light levels so far from the sun, not cold. The Mars rovers for instance use solar panels with batteries and heaters. I'd bet batteries+solar panel+heaters is a LOT cheaper than an RTG.

But you're right, on a mission to pluto they'd have to use an RTG for power, so chemical batteries wouldn't be needed. I hadn't thought of the low light levels. But, the original point is that a heat source is important because electronics don't work the same at such extremely low temperatures.

weird science

[loserhead]

so it says that Charon, Pluto's moon, is warmer than the planet. Since Charon is almost as big as Pluto, I am sure this new tidbit will add more to the deabte concerning what relation the two celestial bodies have with each other and how they came to be paired.

Re:Not degrees

[pranay]

For a change, the journalists got their science right. from the article:

43 Kelvin (-382 degrees Fahrenheit) instead of the expected 53 Kelvin (-364 degrees Fahrenheit)

But then, a fellow slashdotter uses degrees Kelvin and no eyebrows are raised.

Heinlein was wrong about Pluto

[Anonymous Coward]

Heinlein's classic Have Space Suit, will Travel (which I will now call HSSWT) is one of Heinlein's last jouvenille novels to have its science become dated. The other novels had such quaint things as canals and martians on Mars, or a 200 where people had the ability to make synthetic gold, yet people still had to talk to a live bank teller to withdrawl money. HSSWT, until reasonably recently, had no such quaintness to it. However, (minor spoilers follow) there is a scene in the book where the hero has to go to Pluto. In the book, Pluto has an Earth-like gravity--however, Pluto is much smaller than we thought when Heinlein wrote this book; Pluto's gravitation force is only 6% (a little over 1/20th) of Earth's gravity.

He was right about one thing though: It is very cold on Pluto.

Re:Tornadoes?

[hyc]

That's an interesting point. From the article, Pluto receives about 1/1000th as much sunlight as the Earth. From here http://www.powerfromthesun.net/chapter1/Chapter1.h tm we see that the Earth receives 1367 watts per square meter, so we can assume that Pluto typically receives only 1.367 watts per square meter. Dumping the heat from a single P4EE into Pluto's surface could be pretty disruptive, hundreds of watts over a small surface area. The rush of nitrogen vapor would be like a bomb exploding.

Re:Off topic Kelvin joke

[Ed Avis]

A few choice quotations from Lord Kelvin, President of the Royal Society:

Radio has no future.

Heavier-than-air flying machines are impossible.

X-rays will prove to be a hoax.

Apparently these were in 1899. They're all over the net and in print (eg the book Return of Heroic Failures) but I can't find a definitive source in context.