All scorpions fluoresce (glow) under ultraviolet light, and it’s quite impressive to see this for the first time – you can buy an inexpensive UV Torch and go looking for them at night by walking slowly in rocky areas and shining your torch on the ground.
The blue-green glow comes from a substance found in a thin but tough coating in a part of scorpions’ exoskeleton (specifically, the hyaline layer of the cuticle), and newly-shed scorpions don’t glow like this until their new cuticle hardens.
The hyaline layer is amazingly durable – it can survive millions of years, and it’s often found in scorpion fossils even when other parts of the cuticle have already vanished. And yes, fossilized hyaline still glows!
Scientists aren’t exactly sure what purpose the fluorescence serves, but theories include that it protects them from sunlight, that it helps them find each other, or that it may confuse their prey.