This image shows a star cluster forming from the collision of turbulent molecular clouds, which appear as dark shadows in front of the background galactic star field. Star clusters are conceived in the hearts of optically dark clouds where the early phases of formation have historically been hidden from view. But these cold, dusty clouds shine brightly in the infrared, so telescopes like SOFIA can begin to reveal these long-held secrets.
The molecular clouds are surrounded by atomic envelopes, here illustrated in green, which have been detected via emission from ionized carbon by the GREAT instrument on board SOFIA. The spatial offset and motions of these envelopes confirm predictions of simulations of cloud collisions.