The main fuel that the ship used for its chemical engines during normal space flight was atomic hydrogen.

The dark band across the middle of the figure is due primarily to atomic hydrogen in the disk between the Sun and the bar.

I was wondering if we could use Wade's system of storing the atomic hydrogen in solution.

Such molecules were discovered to make up about half of the interstellar matter, the rest being mainly atomic hydrogen.

This indication was found by detecting the extended exosphere of atomic hydrogen.

First, a beam of atomic hydrogen is produced.

Violet hue can occur when the spectrum contains emission lines of atomic hydrogen.

Another minor constituent of the Ganymedian atmosphere is atomic hydrogen.

An electric arc or ultraviolet photon can generate atomic hydrogen.

This is the well-known H-alpha line emitted by atomic hydrogen.