I talked about it again with Dr. Matthew Kenworthy, who is an associate professor at Leiden Observatory.

Oh, that's a great question there.

Well, we certainly think that there can be rainbows on other planets if they've got liquid water.

So one of the ways we see rainbows on our planet is because we have raindrops in the sky, and then you need sunlight as well to shine on the raindrops, and those raindrops then bounce the light and split it up into the rainbow that we see.

So if you look at the other planets in our solar system, there are two possible places to see rainbows.

One of them would be on Titan, which is a moon of Saturn.

But unfortunately they've got lots of thick, hazy cloud in their atmosphere, and also it wouldn't be water droplets, but it might be some other chemical instead.

Can you tell us about that?