The Fossil Footprint is an emission nebula in Perseus that appears relatively small in the sky, due to its distance from Earth. There seem to be conflicting estimates about how far away it is – I am finding a range from about 10 to 12 thousand light years. Either way this image is zoomed in quite a bit compared to my other wide field shots.
The nebula contains a number of massive stars whose UV radiation ionizes the hydrogen clouds making them glow brightly. As with other emission nebulae we’ve seen, there are some beautiful patterns sculpted into the clouds by the radiation pressure from the stellar winds. I especially love the bright yellow walls at the top, formed when gases are compressed by shock waves – real gates of heaven stuff! It’s supposed to bear some resemblance to a footprint, but I’m not seeing it.
