Okay, so maybe I sort of gave it away in the post title…
I know what you’re about to say next. Why are we looking at a mount? What’s so special about a mount—isn’t the telescope itself more important?
And the fact is…I know where you’re going with that. The telescope is important, and without it, the mount would have no purpose. But without the mount, the telescope would be lost—it would have power, but nothing to do.
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.
The celestial sphere is certainly a strange way to think about the night sky.
It makes sense to use globes to diagram the Earth. The Earth, after all, is a roughly spherical planet, and flat paper maps have a way of distorting distances.
The sky, though? Seriously? I mean, we all know the universe isn’t exactly a defined sphere that barely extends past Earth’s surface, right?
Funnily enough, the celestial sphere depicts all the stars as sitting on the plane of its surface like thumbtacks on a ceiling. Planets are described as following regular paths around this odd-looking sphere.
Pretty strange way to think about the night sky, right?