A nebula of gas and dust churns along the northeast rim of a large molecular cloud dubbed the Cepheus Bubble.

With a diameter spanning 500 light-years, the Cepheus Bubble sits about 2,700 light-years away toward the northern constellation Cepheus. Astronomers believe the bubble formed between to 10 million years and 20 million years ago in one of the outlying regions of our Milky Way galaxy’s spiral arms.

Shown here is the SH-140 nebula along the northeast circumference of the bubble.

Skywatcher Tom Smith recorded this image of the SH2-140 nebula on Sept. 10 as part of a nightly program led by Adam Block at Arizona’s Kitt Peak Observatory.

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-- SPACE.com Staff

Credit: Tom Smith/Adam Block/NOAO/AURA/NSF