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I'm confused by their description of the ecliptic.. " For them, Venus was a single object and they observed its changing position, along with the other planet
by everyone 7y ago
I'm confused by their description of the ecliptic..
"
For them, Venus was a single object and they observed its changing position, along with the other planets and the moon. These positions all lie on the same great circle, called the ecliptic, defined by the apparent motion of the sun as seen from the earth during the course of a year.
"
Isnt the ecliptic basically a line (or very very skinny ellipse) from Earths perspective as we are on that great disc ourselves?
Also "For them, Venus was a single object" so for us its not??
- T-hawk 7y agoVenus: some ancient cultures recognized its "evening star" and "morning star" appearances as the same object; some thought they were two different phenomena. The ecliptic, physically, is the plane of Earth's orbit around the Sun. It is so named because that is where eclipses happen, when the Moon crosses that plane. (Or other planets; we call that event a transit, but that's the same as a very annular eclipse.) The projection of that plane as viewed on the sky from Earth is a great circle (or slightly offset, because the observer is on Earth's surface not at its center.) If the Earth were transparent, you could see the entire circle. In reality, you see a segment of it from horizon to horizon, as a line. All the planets and the moon seem to stay near the ecliptic in the sky, because their orbits are within a few degrees of coplanar with Earth's.
- everyone 7y agoI'm realising I look at this differently to the article writer + u. I would say, the ecliptic is a great disc. But when your on a disc, from your perspective that disc looks like a straight line, not a circle...