I have what is probably a simple question: How is the orbit of the Earth actually measured? I know it takes 365.26 days for Earth to orbit the Sun, but how is that actually measured? Further, would we know if Earth's orbit changed?
Thanks,
Gond
erikfriend
Posted: Tue Aug 04, 2009 10:38 pm
Joined: 22 Jul 2009 Posts: 2
Measuring the length of a year
If the plane of the solar system is roughly aligned with the plane of the galaxy, then one could use the galactic center as a reference point. At one side of our orbit, the sun would be between us and the galactic center. At the other side of the orbit, Earth would sit between the sun and the galactic center. A year could be measured as the time required for the Earth to move from the far edge of the orbit, to the close edge, and back again, all relative to the galactic core.
