# Cooling down a container in outer space

If I have two containers filled with very hot water(~210°F) with one in outer space and one on earth, which one has a higher rate of cooling initially? Imagine the containers are single wall metal containers that are able to withstand any pressure.

Intuitively I would assume the one in space would cool faster because the average temperature of space is 3°K. However a vacuum flask is an extremely good insulator since the only way heat can transfer is through radiation. Space is an even more extreme vacuum then any flask so would that mean that it "insulates" even better?

If allowed to come to thermal equilibrium, the space container would certainly lose more energy overall, but is the rate affected by the temperature difference a la Newton's Law of Cooling or does it lose energy at the same rate no matter what?

• The energy loss in the vacuum of space will be due entirely to thermal radiation, using the equation $P=\epsilon \sigma AT^4$. Jul 24 '13 at 23:05
• I think there is not enough information to answer it, we need to know how close the container material to black body to know how much it really radiate, and in the same time absorb sun's, earth's, and moon's radiation, also it's thickness and heat conductivity will play important role.
– TMS
Jul 24 '13 at 23:38
• Are you asking which container will cool to its environment's temperature the fastest, or which will cool the fastest at the beginning, at the temperatures you've give us? Also, what metal are we using for the container? Thermal conductivities and emissivities can vary greatly between materials. Jul 24 '13 at 23:40
• I thought I posted a comment here but it isn't showing up. @Joshua-I want to know which one cools faster initially. I have modified the question to reflect this. I don't think the metal matters since it's the same metal for both. But just for the sake of the question let's just say it's iron. Jul 24 '13 at 23:58
• @TMS-The container is in deep space so any other radiative bodies are negligible to the the answer. My main focus is on the container in a vacuum vs the container in a regular atmosphere. You could use STP for the atmospheric conditions. Jul 24 '13 at 23:59