EU Sending a Probe To the Sun 160
First time accepted submitter Mindflux0 writes "The European Union is going forward with the proposed Solar Orbiter, a space probe designed to study the sun. The probe will orbit closer to the sun than any other man-made object at a sizzling 42 million km. It's planned to launch in 2017 for close to a billion euros."
Re:Too much sunlight is as bad as too little... (Score:5, Informative)
The 'heat' is the solar radiation heating up what it strikes. That heat will radiate back out into space. Likewise the dark side of the space craft will be close to absolute zero.
This is an imperfect understanding of heat and how it works in space. Heat is HARD to get rid of. Very, very, hard. Heat hitting the craft will radiate back into space? Not very efficiently. Radiated energy is about the least effective way to get rid of heat. Very space and mass intensive. The ISS has almost as many square meters of heat radiators as it does solar panels. And the ISS has it easy, with a planetary shadow to work with.
Why is it so hard? Because space isn't cold. The whole 'space-is-barely-above-absolute-zero' thing is technically true and yet wildly inaccurate. Yes, the total amount of energy in a given volume of space is absurdly low. But that's not because the contents are cold. It's because there is nothing there to be measured. Space is a vacuum. As in vacuum thermos. That magical container that keeps hot things hot and cold things cold.
To say that the absolute cold of space will keep things cold implies that there is some cold substance in space that the heat can be transferred to. That simply isn't the case.
The far side of the spacecraft from the sun is going to be exactly the same temperature as the near side because the natural heat conductivity will be orders of magnitude higher than any heat differential caused by radiating heat. Both sides will be baking.