Do 'Space Rainbows' Exist Outside of Planetary Atmospheres?

[BrowncoatsRule]

My friend's son (age 5) absolutely loves space. It's great to see such a strong interest in science in kids that age. He calls me the astronaut guy since I told him I've wanted to be an astronaut since I was a kid, and that I also love space. We recently shared a discussion about the planets of the solar system, and how Earth is the only planet to have liquid water on its surface. I guess he had recently learned about rainbows in school, and knew that it was the water vapor in the atmosphere that allowed us to see rainbows after a storm. He told me he was sad because there was no water in space, and therefore there weren't any rainbows in space.

Now I know water exists in space, but as ice and gas rather than liquid water due to pressure and temperature limitations. His comment made me realize that I had never thought about whether rainbows exist in space outside of a planet's atmosphere. I suppose all a rainbow requires is a transparent material to refract the light, and ice water in space could certainly do that. Have we ever imaged a "space rainbow" before?

 

[russ_watters]

In space? No. On other worlds...?

http://science.nasa.gov/science-news/science-at-nasa/2005/25feb_titan2/

 

[phinds]

I suppose all a rainbow requires is a transparent material to refract the light, and ice water in space could certainly do that.

No, the crystalline structure would not reflect/refract light in any systematic way, as water droplets in the air do so that wouldn't work.

 

[snorkack]

Halo

Ice hexagonal crystals do form various haloes in atmosphere, like the 22 degree rings. Do these also work in space?

 

[Naty1]

Earth is the only planet to have liquid water on its surface.

We have increasing evidence of other 'planets' with liquid water...any mass in space with atmospheric humidity can potentially have a rainbow...of course you need sunlight too.