What is the coldest body in our Solar system?

[m1omg]

What is the coldest body in our Solar system that we know of?

[Tucson_Tim]

Does the Ort Cloud qualify as part of the Solar System? Or does the 'Solar System' end with that used-to-be-a-planet Pluto?

[jamini]

What is the coldest body in our Solar system that we know of?

Paris Hilton?

Sorry, couldn't resist.

If I had to guess, I'd say Eris at its aphelion, which is ~97 AU from the Sun or roughly twice the distance as Pluto; hence, I would imagine it to be correspondingly colder.

[m1omg]

Sol system extents far beyond Pluto.
Eris is certainly not.
Sedna has it's aphelion 1000 AU.
Is there anything colder than it?

[BISMARCK]

While it's probably not the coldest place, I have read that Titan is probably the only place in the Solar System where you'd freeze to death even in a space suit, since it actually has a cold atmosphere to drain your heat, as opposed to the vacuum environments you'd find on Asteroids or those dwarf planets way out there.

[m1omg]

If you have good heating in your spacesuit, you will not freeze.

[Saluki]

If you have good heating in your spacesuit, you will not freeze.

That is easier to say than do. You would need extremely good insulation, and a decent source of energy, as well as being impervious to the Titan atmosphere. Remember also that it has to be light enough and flexible enough that a man can actually move around in it.

[Noclevername]

Might be easier to just drive around in a heated and vacuum-insulated vehicle, and use telepresence on the surface.

[m1omg]

That is easier to say than do. You would need extremely good insulation, and a decent source of energy, as well as being impervious to the Titan atmosphere. Remember also that it has to be light enough and flexible enough that a man can actually move around in it.

Aerogel will do it .That thing is used on a Mars rovers and can hold inner temp. of the equipement at 25 degress Celsius while the outside temp. can be -100 degress.Read more on: http://en.wikipedia.org/wiki/Aerogel .
With modern technology you can walk on every place of the Sol system except Sun.
And Tian atmosphere is only 2 bar and almost pure N2.That smog is primarily in the high layers.And today's NON AEROGEL insulation systems used on a liquid hydrogen stations (for LOH powered cars like the new variant of BMW) can hold a boiling coffee 80 days until it cool enough to be drinked.

But yes, if you use ordinary ISS spacesuit, you will freeze, however, it is easy to engineer one in what you will not freeze.

[m1omg]

And why use vecihle?Stop underestimating modern technology.
And Mars is only 30 degress warmer than Titan in some places and also it has an atmosphere.

[Noclevername]

And why use vecihle?Stop underestimating modern technology.
And Mars is only 30 degress warmer than Titan in some places and also it has an atmosphere.

Just barely. Mars' thin atmosphere can't carry away much heat. Titan's atmosphere is both colder and much denser.

.

[Noclevername]

Aerogel is not flexible. It would make for a very awkward spacesuit design.

But yes, if you use ordinary ISS spacesuit, you will freeze, however, it is easy to engineer one in what you will not freeze.

It's very easy to conceptualize one. Engineering it, and actually building it, would be much more complicated.

[jamini]

With modern technology you can walk on every place of the Sol system except Sun.

Would that include Mercury:

Surface temperatures on Mercury range from about 90 to 700 K (−180 to 430°C, −292 to 806°F)

To what temperature extremes have Aerogel suits been tested and proven to sustain human life?

,

[jamini]

And why use vecihle?Stop underestimating modern technology.
And Mars is only 30 degress warmer than Titan in some places and also it has an atmosphere.

Your point? You do realize Titan is quite a bit farther away than Mars?

[jamini]

Sol system extents far beyond Pluto.
Eris is certainly not.
Sedna has it's aphelion 1000 AU.
Is there anything colder than it?

How did you calculate the temperature differential between 97au and 1,000au from the Sun?

[dhd40]

What is the coldest body in our Solar system that we know of?

Depends on what you mean by "body". If I understand it correctly, there are some places (crater bottoms) on our moon which never will be touched by any sunlight. Without knowing thermal conductivity values of our moon´s material in these places, I would expect that these places are very cold.

[Noclevername]

Depends on what you mean by "body". If I understand it correctly, there are some places (crater bottoms) on our moon which never will be touched by any sunlight. Without knowing thermal conductivity values of our moon´s material in these places, I would expect that these places are very cold.

There are Outer Solar System bodies with sunless craters, too. No doubt even colder than the Lunar ones.

[dhd40]

There are Outer Solar System bodies with sunless craters, too. No doubt even colder than the Lunar ones.

If there are, you´re right. Must be very deep craters if these Outer Solar System (small) bodies are rotating arbitrarily. Most probably you´re right.

[Saluki]

With modern technology you can walk on every place of the Sol system except Sun.

Hmm.

Mercury (already mentioned)
Venus
Jupiter
Saturn
Neptune
Uranus

All of the above would be extremely difficult to downright impossible given current technology.

[Nereid]

Hmm.

Mercury (already mentioned)
Venus
Jupiter
Saturn
Neptune
Uranus

All of the above would be extremely difficult to downright impossible given current technology.

I'd add Io and Europa, among the large bodies (the radiation shielding you'd need would likely make walking next to impossible), and the Jovian moons inside Io's orbit as well.

I think you'd find it difficult to 'walk' on most small bodies too ....

[tony873004]

I'd add Io and Europa, among the large bodies (the radiation shielding you'd need would likely make walking next to impossible), and the Jovian moons inside Io's orbit as well.

Io and Europa are tidally locked to Jupiter. You could walk on the side that faces away from Jupiter.

[Noclevername]

If there are, you´re right. Must be very deep craters if these Outer Solar System (small) bodies are rotating arbitrarily. Most probably you´re right.

Some of Neptune's moons, maybe. Or stabilized pairs like Pluto and Charon.

[Grashtel]

Io and Europa are tidally locked to Jupiter. You could walk on the side that faces away from Jupiter.

The radiation isn't from Jupiter, its from particles trapped in its magnetic field (like the Van Allen Belts around Earth), I don't think its directional enough that you could hide behind a moon.

[m1omg]

How did you calculate the temperature differential between 97au and 1,000au from the Sun?

Using Celestia.According to it, the aphelion temperature of Sedna is only 9 Kelvin, frigidly cold -264.15 degress Celsius, or -443.47 degress Fahrenheith.And reason with common sense, object 1000 AU from the Sun is logically colder than one 97 AU from Sun.Stop demanding calculation, all you need is logic.
And aerogel spacesuits were never constructed but could be.But it is a impractical in spacesuits, it will shatter with a little pressure change; however it could be more practical as insulation for habitats and when protected by the layer of the harder thing, it could be almost perfect insulation. but read;
http://en.wikipedia.org/wiki/Aerogel

Look:






[IMG]http://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Stardust_Dust_Collector_with_aerogel.jpg/660px-
Stardust_Dust_Collector_with_aerogel.jpg[/IMG]




It basically conducts (almost) no heat.

[m1omg]

A sunless crater on Senda might have imo temperatures about the temperature of the cosmic background radiation+cosmic radiation+ micrometeorites.I guess it will be about 4-5 K.

[jamini]

Using Celestia.According to it, the aphelion temperature of Sedna is only 9 Kelvin, frigidly cold -264.15 degress Celsius, or -443.47 degress Fahrenheith.And reason with common sense, object 1000 AU from the Sun is logically colder than one 97 AU from Sun.Stop demanding calculation, all you need is logic.

I didn’t demand anything. I was asking if you had performed any precise calculations to demonstrate specifically what the temperature differential would be between 97au and 1,000au. My common sense would tend to dictate that the Sun’s radiation at 97au would be minute; hence, the difference between 97 and 1,000 would be fairly insignificant. What I am asking is how you can quantitatively define how much colder Sedna is compared to Eris, as you claim?

And aerogel spacesuits were never constructed but could be.But it is a impractical in spacesuits, it will shatter with a little pressure change; however it could be more practical as insulation for habitats and when protected by the layer of the harder thing, it could be almost perfect insulation. but read; http://en.wikipedia.org/wiki/Aerogel It basically conducts (almost) no heat.

But you said:

Aerogel will do it .That thing is used on a Mars rovers and can hold inner temp. of the equipement at 25 degress Celsius while the outside temp. can be -100 degress.Read more on: http://en.wikipedia.org/wiki/Aerogel .With modern technology you can walk on every place of the Sol system except Sun.And Tian atmosphere is only 2 bar and almost pure N2.That smog is primarily in the high layers.And today's NON AEROGEL insulation systems used on a liquid hydrogen stations (for LOH powered cars like the new variant of BMW) can hold a boiling coffee 80 days until it cool enough to be drinked. But yes, if you use ordinary ISS spacesuit, you will freeze, however, it is easy to engineer one in what you will not freeze.

I did read the link; thanks. And I think what you meant to state is that the heat resistant properties of Aerogel appear promising for future application in space missions. And that perhaps this material may some day even be developed to the point that may allow humans to walk on now seemingly unlikely surfaces.

Extraordinary claims require extraordinary evidence.

.

[jamini]

A sunless crater on Senda might have imo temperatures about the temperature of the cosmic background radiation+cosmic radiation+ micrometeorites.I guess it will be about 4-5 K.

There are more considerations for determining the coldest body besides simply distance from the Sun. For instance, according to NASA, Triton is the coldest measured body in our solar system, though certainly not furthest from the Sun.

Triton is colder than any other measured object in the Solar System with a surface temperature of -235° C (-391° F).

[m1omg]

There are more considerations for determining the coldest body besides simply distance from the Sun. For instance, according to NASA, Triton is the coldest measured body in our solar system, though certainly not furthest from the Sun.

This is almost certainly wrong.Body 1000 AU from the Sun will be colder ,certainly."Small diference" between about 14 K and 9 K is only small by human terms.

[m1omg]

There are more considerations for determining the coldest body besides simply distance from the Sun. For instance, according to NASA, Triton is the coldest measured body in our solar system, though certainly not furthest from the Sun.

Oh, coldest MEASURED body.Voyager 2 measured it, but we did not measured the temperatures of Pluto or KBOs yet.But we can calculate it.

[m1omg]

According to this temperature calculator, http://www.astro.indiana.edu/~gsimon...perature1.html , the temperature of Sedna assuming it's albedo is 0.2, is only 9 Kelvin , which confirm Celestia number.

Eris is 29 K cold, but this is +20 K temperature difference.

From 97 AU the Sun is still relatively bright.
From 1000 AU, however, it have 1/2 the brightness of the full moon.
And according to Wikipedia, temperature on Sedna never rises above 30 K even in it's perihelion.
I guess that Sedna is the coldest (discovered) body in our Solar system.