Blood moon. The reason why the Moon takes on a reddish color during totality is a process called Rayleigh scattering. This is the phenomenon responsible for the sky to be blue and the sun to appear yellow.
----------Rayleigh Scattering----------- ---------Why is the sky blue?---------- Elastic scattering of light or other electromagnetic radiation by particles (atoms or molecules). It can occur when light travels through transparent solids or liquids - most prominently seen in gases. Rayleigh scattering of sunlight in the atmosphere causes diffuse sky radiation, which is the reason for the blue color of the sky & the yellow tone of the sun itself.
The Sword of Orion - the three stars that make up the weapon hanging off the belt of this famous celestial hunter. The image showcases the amazing mix of physical and optical processes including atomic emission, Rayleigh scattering, reflection and absorbtion of light, that go on in this star forming region to create this kaleidescope of colours and details.