Looks Like a Full Moon Tonight

Let's consult with a spider to make sure.

Howdy! It’s Joey, back with more Fun Fact Friyay. This fact may cause you to jump for joy.

Photo by Erik Karits on Unsplash

Jumping spiders can see the moon from Earth.

I am a fully grown adult, and I’m still tickled by seeing the moon in the night sky. Alas, I will never see the moon from up close (I get motion sickness far too easily to ever handle zero-gravity), but I will enjoy it with my two feet planted firmly on the ground.

It turns out I may very well share that enthusiasm with jumping spiders.

Now, many people jump when they encounter spiders. I understand that reaction—suddenly seeing something scurrying by you can be unsettling—but these little critters are pretty dang cool.

Back in 2017, when Twitter was a fun place to have amusing conversations, a team of scientists got into a discussion. Jamie Lomax, an astronomer at the University of Washington, discovered her office was being overrun by spiders.

(Okay, overrun makes it sound bleak. There were a few spiders that had gotten into her working area.)

Lomax tweeted out her predicament. Soon, she and her colleague, Professor Emily Levesque, were parsing through responses of how to handle the spiders, which they had discovered were Zebra Spiders. This creature is a type of jumping spider common to the Pacific Northwest.

One response suggested using laser pointers, because these spiders apparently share the same kind of fascination with laser pointers as cats do. Levesque showed us some early results:

Soon, Nate Morehouse, who studies spider vision for the University of Cincinnati (what a cool field of study), got into the mix.

Morehouse explained that spiders have impressive vision that helps them catch prey. They can spot things off in the distance as well as creatures that are significantly larger, like dogs, cats, and pigeons.

This special vision is due to the jumping spider having eyes that are very much like a Galilean telescope. To put it simply, the eyes are basically tubes with a lens at both ends. One lens collects and focuses the light; the other enlarges the image, giving the spider enhanced vision with stunning detail.

The jumping spider’s visual acuity—how well it can differentiate between objects—allows it to see things 0.07 degrees apart. The entire moon is about 0.5 degrees.

That leads us to a delightful nuance: If a jumping spider cranes its neck upward—perhaps while chasing after a laser pointer outside—it could very easily have the moon hit its eye like a big pizza pie.

Depending on the brightness and other visual effects of the area, the spider might even be able to see craters within the moon’s surface.

Will the spider start dancing as “That’s Amore” plays in the background? That’s still TBD, but it’s worth a shot. Maybe you’d have better luck with Van Halen’s “Jump.”