Is there single atoms in the void of space,if so what kind?

Question

i understand about solar radiation and where it comes from ,what i can,t understand is that if there is atoms or even small particles sprinkled around in the void of space they would be hit in all directions from light photons.i know that when a photon hits an atom it gives of light,so what kind of atoms are out there and why isn,t the void of space a brighter

place.

Answer 1

A good question.  Unstable, reactive species like free radicals eg CH3+, NO3-, OH- etc. and monatomic O, H, N, Cl etc. last a lot longer in the near-vacuum of space than at sea level atmospheric pressure.  There's nothing for them to react with.  And at temperatures close to absolute zero in interstellar space, very weakly bonded compounds, like argon compounds can exist.

Answer 2

Yes, there are atoms out there, but mostly molecules, like H2. An H2 molecule may absorb a high-energy photon and then emit a lower energy photon. But there are so few molecules out there that the glow is undetectable. Even at sea level in our atmosphere, the air barely glows enough to make the sky blue. The pressure in space is a tiny fraction of a percent of atmospheric pressure.

Answer 3

Signifigant solar radiation requires being close to a star therfore there isnt a whole lot of solar radiation in an area of deep space.  The most common atoms out in space is probably hydrogen and some helium.  But in most regions of space the density of matter is very very low, that is they are spread far apart.   There is a lot of solar radiation in space in the solar system because we are close to a star.  If you have tiny bits of matter spread out thinly over vast amounts of space far away from any source of radiation then you wont have very many excited atoms in a region of space at any given time.  There is a constant amount of radiation in empty space called the cosmic microwave background radiation which i believe is about 3K left over from the big bang but this is a very low amount requiring special equipment to see.