Giant Molecular Clouds

This image shows a filament of cosmic dust over ten light years long! It’s part of a giant cloud of cold gas and dust that’s starting to collapse under its own gravity to form stars. Newborn stars are hidden inside. The cosmic dust grains here are so cold that observations at millimeter wavelengths were needed to detect their faint glow, shown as orange in this false-color image.

Giant molecular clouds like this range from 15 to 600 light-years across. And they’re very dense… for outer spac...