The Crab Nebula is the remnant of a supernova which was observed almost 1000 years ago. Although it corresponds to one of the ...

The Crab Nebula, a supernova remnant nebula ... The red hue is evidence of ionized hydrogen, which gives off visible light at a wavelength of 656.3 nm. Likewise, the green is from a rare ...

The Veil Nebula is roughly 2,400 light ... are visible from Earth, primarily with a telescope or binoculars. The challenge has previously asked observers to observe M1 the Crab Nebula and C39 ...