Imagine that you’re living sometime around 2000 BCE, give or take a thousand years or so. That’s about 4000 years before our time.
You look up at the sky at night, and see it filled with numerous points of light. Some of them stay mostly fixed, but move mysteriously in circles around the north pole. Others move with the rest, but wander a bit from time to time.
And then there’s the sun, whose brilliant rays light the day. The moon, like the sun, doesn’t seem to follow the path of the lights in the sky. It even changes its shape, and sometimes disappears entirely.
Wouldn’t you wonder if there was some pattern to these otherworldly motions? Wouldn’t you devote time to studying them and seeing if you could predict them?
We have a bit of a shorter post today—I thought precession warranted its own post, before I go on to talking about the ecliptic.
Precession refers to the way Earth wobbles around on its axis, a bit like a top. This motion is caused by the sun and moon’s gravity tugging on the planet, and is key to understanding how many ancient cultures viewed the sky.
Can you find a horse in this image of the night sky?
Yeah, me neither. I’m lost. I see the Great Square of Pegasus because I know what to look for, but I still don’t see a horse.
Okay, so now I see half a horse. Where’s the rest?
Your guess is as good as mine, guys. Truth is, constellations very rarely look like what they’re named after. Constellations are more like relics of our ancient past than actual descriptors of what we see up there in the sky. But they do serve a purpose, even if that horse up there is missing his back legs.
I really find myself wondering if whoever made up Pegasus was concerned with animal rights… No animals were harmed in the making of this sky map…
Okay, yeah, never mind.
Where was I? Ah, that’s right. The purpose of the constellations, and the reason why it really doesn’t matter if they don’t look like their names say they do.