Jumping spiders & the moon

Jumping spiders are able to see the Moon.

Jumping spiders have extremely good vision. Their visual acuity, meaning how well they discern two discrete objects, is on par with cats, pigeons, and some dogs. Their eyes work like little Galilean telescopes, with a visual acuity allowing jumping spiders to resolve objects 0.07 degrees apart, the full moon—which covers a whopping 0.5 degrees on the sky—would be easy to spot, if the spiders looked up at night.

The moon is almost certainly bright enough for them. Its light would hit between five and six light-detecting cells on their retinas, which might just be enough for them to make out the subtle darkness of the moon’s craters.