A question of space travel

[Cloengaa]

Hey all,

I thought about space travel in the future.

As I understand it then different gasclouds in space are very very hot. As we travel between earth and the moon or Mars we do not pass these clouds, but say in the future when travel becomes more extensive and we can travel in the universe.

Would we not have to avoid such clouds ? I mean a cloud consists of matter and I take it the spacecraft would feel the intense heat in the clouds or am I totally wrong ?

 

Chris

[wulfrun]

In most cases you'd be wrong. Temperature is a measure of how fast gas molecules/atoms are moving. Most gas clouds in space as so low in density you'd struggle to notice you were in one, so the heat transfer would be negligible.

I know you tend to think of, say, putting your hand in the hot air in an oven but that is gas at atmospheric pressure and density. Interstellar gas clouds are mostly better than any "vacuum" created on earth.

Edited August 2, 2021 by wulfrun
typo

[Lariliss]

The densest area that we might pass would be a nebula.

http://www.astronomy.ohio-state.edu/~ryden/ast162_3/notes11.html

-'The densest nebulae can have densities of 10,000 molecules per cubic centimetre (or sometimes even more)'.

-The hottest interstellar gas has a temperature of 8000 Kelvin (or more). (The Solar System, by the way, seems to be located within a large, low-density bubble within the interstellar medium.)

For sure, the travelling path should avoid asteroid belts, would have probably same approach as we do have now, avoiding orbiting of large mass bodies or using them for acceleration.

Our space craft would be something totally new piece of technology that we have now to travel further.

[ollypenrice]

On 02/08/2021 at 11:20, wulfrun said:

In most cases you'd be wrong. Temperature is a measure of how fast gas molecules/atoms are moving. Most gas clouds in space as so low in density you'd struggle to notice you were in one, so the heat transfer would be negligible.

I know you tend to think of, say, putting your hand in the hot air in an oven but that is gas at atmospheric pressure and density. Interstellar gas clouds are mostly better than any "vacuum" created on earth.

Agreed. You can put your hand into a hot oven without being burned, even at atmospheric pressure, but you can't touch a metal object in the oven even though the gas and the metal have the same temperature. There are more atoms and molecules in metal than in gas...

Olly

Edited August 24, 2021 by ollypenrice
Typo

[vlaiv]

Here is interesting question - even if temperature in nebula is very high - does room temperature gas (air) produces more energy transfer than it?

Temperature is measure of average energy of particles in a gas.

10000 molecules per cm^3 in nebula will all have high kinetic energy so that their average energy is also high - high temperature, but in air at room temperature and 1 atmosphere of pressure we have roughly 25 x 10^18 molecules.

Out of these 25 x 10^18 molecules, according to Maxwell–Boltzmann distribution - I think there are more than 10000 that have higher energy than average energy of those 10000 molecules in very hot interstellar gas / nebula?

[Lariliss]

It depends on the density of the plasma (ions and electrons), their speed and the speed and size of a spaceship. Also it depends on the chemical structure of the gas and chemical reactions occurring both in the gas and on the surface of dust grains lead to much more complex compounds.

The temperatures about 300 times hotter than the solar corona cloud was discovered by Voyager in 1979. Voyager 2 survived passage through this region because the density of the hot gas is very small - only about 30 particles in a cubic foot; therefore there were not very many ions hitting the spacecraft and hitting it up.

Scientific studies are carried out to understand the relationship between density and heat.

The Low Energy Charged Particle instrument was designed to measure fast (few thousand miles per second) ions and electrons' influence.

[apaulo]

space travel, is always interesting, there is some great stuff by david adair on youtube about   speed and space travel and a lot more. well worth viewing.  aliens, moon landings , nasa area 47 plenty for cloudy nights.