What astronomers have detected is actually a vast hydrogen cloud, whose relative closeness to Earth will provide an opportunity for detailed study of its development.

"Sir, I get a fluctuating energy reading from this hydrogen cloud."

The ship unfurled its night-dark wings and dived into the hydrogen clouds.

"Plasma... like the plasma contained within that hydrogen cloud?"

Kirk stared at the hydrogen cloud on the bridge screen.

Once they knew what to look for, they could see the same shimmering in the stars above and the hydrogen clouds below, within a well-defined circle.

This can be seen by the displacement of the neutral hydrogen clouds from the stars.

These nebulae are areas of intense star formation within giant molecular hydrogen clouds.

Groggily Steve allowed himself to be propelled toward the bath, his mind a whirl of hydrogen clouds and non-Newtonian force fields.

Neutral hydrogen clouds are detected via the 21 cm emission line.