Weather Fundamentals

The Seasons

What is the ecliptic plane

The ecliptic plane is the plane of Earth’s orbit around the Sun. Ancient astronomers were able to trace the ecliptic as a line across the sky, even though they did not know Earth actually orbited the Sun. They merely followed the position of the Sun compared to the position of the stars in the sky, figured out (despite the Sun drowning out the light of the other stars) where the Sun was every day, and noticed that every 365 days or so the positions would overlap and start going over the same locations again. That line marked a loop around the celestial sphere. Astronomers marked the line using twelve zodiac constellations positioned near and through the loop.


This is a web preview of the "The Handy Weather Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App