Like shiny gemstones embedded in a rocky matrix, star-forming clouds of dust and gas glimmer within the swirling structures of the galaxy in an infrared image from ESA’s Herschel Space Observatory.
The image was acquired as a part of Hi-GAL, a survey mapping the entire plane of the Milky Way in a wide range of infrared light that Herschel was specially designed to detect. The image above is just a small section of a larger version, which in itself is just 1/30th of the entire Hi-GAL survey. (Download a larger image here.)
Normally invisible to our eyes, vast filaments of gas and dust fill the plane of the galaxy where stars like our sun reside. As these cold clouds of interstellar material collapse, they get denser and denser until they eventually form stars, which then blaze with heat and light.
The energy from these newborn stars blasts out into nearby space, illuminating the shrouds of material they were born in as well as ionizing them with shockwaves of radiation.
These ionized “shock fronts” also release light in wavelengths corresponding to the elements within the clouds, and can also eventually lead to the formation of yet more stars — a continuous cycle of star birth on a galactic time scale.
Image: A portion of an image from ESA’s Herschel Space Observatory showing star-forming clouds in the galactic plane. Credit: ESA/PACS & SPIRE Consortium, S. Molinari, Hi-GAL Project