Dense knots of gas and dust located in the center of NGC 281 form jagged structures that are exquisitely resolved by the Hubble Space Telescope's Advanced Camera for Surveys. This zoom dives deep into the Cassiopeia constellation, then dissolves into a wide view of NGC 281. Pushing deeper with the zoom reveals dark globules of gas and dust near the center of the star-forming region.
These globules are named after astronomer Bart Bok, who proposed their existence in the 1940's. Bok hypothesized that giant molecular clouds, on the order of hundreds of light-years in size, can become perturbed and form small pockets where the dust and gas are highly concentrated. If they capture enough mass, they have the potential of creating stars in their cores.