I'll have to give it a look!

If you find the cosmos soothing, another topic I enjoy feeling small about is deep time. A natural history twist instead of a space one.

In college I made and gave public presentations on a scale model of the solar system. Many people were nervous or felt intimidated by the size of the space they saw, but a few people had their eyes opened to how comforting it is to be insignificant. You're in good company!

Consumer lasers aren't going to be powerful or well calibrated enough for this to be an issue. The main phenomenon is Rayleigh scattering, the same thing that causes blue sky/red sunset, so red would travel farthest, and a hypothetical yellow would travel farther than green. There are some other less common factors like air pollution that could change how this plays out.

There's lots of hydrogen in space but it's spread so thin it's basically non-existent. On the other hand, every year we collectively emit 41 billion tonnes of water made from hydrogen that has been locked away in hydrocarbons. Also CO2 which is the part we're usually concerned about.