Upload

Loading icon Loading...

This video is unavailable.

Year On Earth

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to like cassiopeiaproject's video.

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to dislike cassiopeiaproject's video.

Sign in to YouTube

Sign in with your Google Account (YouTube, Google+, Gmail, Orkut, Picasa, or Chrome) to add cassiopeiaproject's video to your playlist.

Uploaded on Apr 20, 2009

A year on earth is measured by one complete trip around the sun. Seems simple enough but there is a problem. The earth doesnt travel in a path around the sun that returns it to its starting point. So how do we know when the year starts or ends?

Loading icon Loading...

Loading icon Loading...

Loading icon Loading...

The interactive transcript could not be loaded.

Loading icon Loading...

Loading icon Loading...

Ratings have been disabled for this video.
Rating is available when the video has been rented.
This feature is not available right now. Please try again later.

Loading icon Loading...

Advertisement
Loading...
Working...
Sign in to add this to Watch Later

Add to