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Hermite Crater

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Ian Dunn
647114.  Thu Dec 17, 2009 9:27 am Reply with quote

Apart from places on Earth where humans have created very cold temperatures, the coldest place in the solar system is the Hermite Crater on the Moon.

Nasa's Lunar Reconnaissance Orbiter has recorded temperatures on the south-western edge of the crater floor of 26K (-249C).

Source: BBC

 
Ion Zone
647203.  Thu Dec 17, 2009 4:55 pm Reply with quote

Colder than behind Pluto? (I'm assuming it's to do with its rotation matching Earth's?)


Last edited by Ion Zone on Fri Dec 18, 2009 4:07 pm; edited 1 time in total

 
Davini994
647233.  Thu Dec 17, 2009 5:40 pm Reply with quote

Empty space is 2.7K, is it that much more in the Solar System?

 
Ian Dunn
647289.  Fri Dec 18, 2009 2:52 am Reply with quote

Ion Zone wrote:
Colder than behind Pluto? (I'm assuming it's to do with its rotation mating Earth's?)


Maybe they count the Kuiper belt as the end of the solar system.

Davini994 wrote:
Empty space is 2.7K, is it that much more in the Solar System?


Empty space is colder than the solar system, but that is because there are no stars to warm it up.

However, the Boomerang Nebula is the coldest place in the universe yet recorded, which is 1K.

 
Gray
647320.  Fri Dec 18, 2009 6:20 am Reply with quote

The first sentence of that article says:
Quote:
The Moon has the coldest place in the Solar System measured by a spacecraft.

(my emphasis) This does not mean that the coldest place in the Solar System is on the Moon. It's just that we've not accurately measured temperature in many other places using a spacecraft.

 
Leith
651166.  Wed Dec 30, 2009 5:50 pm Reply with quote

Ian Dunn wrote:
However, the Boomerang Nebula is the coldest place in the universe yet recorded, which is 1K.

On a somewhat pedantic note:

To the best of my knowledge, the Boomerang Nebula remains the source of the lowest recorded naturally occurring temperature.

The coldest known point in space* is, I think, currently on-board ESA's Planck spacecraft. It is sitting in the Earth's shadow, about four times as far away as the moon, studying the Cosmic Microwave Background (CMB).

The temperature of the CMB radiation is the 2.7K that Davini mentions above. In order to be able to see the CMB properly, Planck's instruments have to operate at a much lower temperature and so are cooled to 0.1K. At this temperature, Planck can discriminate temperature variations equivalent to detecting the body heat of a rabbit on the moon from Earth.

http://www.esa.int/science/planck

* i.e. excluding cryogenic systems on Earth

 
PDR
651168.  Wed Dec 30, 2009 5:58 pm Reply with quote

Leith wrote:
It is sitting in the Earth's shadow, about four times as far away as the moon, studying the Cosmic Microwave Background (CMB).


How can a spacecraft maintain a position in earth's shadow but in a solar orbit which is a million miles larger in diameter than the earth? Surely if it was maintaining the same orbital period as the earth, but in a larger orbit, it would need to be continually pushed sunwards?

Sorry - the engineer in me needs to know!:

EDIT:

It's OK - I looked it up. It's the outer lagrange point (cunning!).


PDR

 

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