Back to Home

Blackholes Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Blackholes I | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
No Violations. Laws Stay.

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Alexander on March 12, 2001 14:47:21 UTC

Earth and Moon are interacting gravitationally slightly non-centrally because Earth is not spherical - there are 2 tidal bulges on Earth - one due to Moon's pull and the opposite one due to centripetal accelearation of Earth orbiting center of mass of Earth-Moon system.

Due to Earth's rotation they are not exactly under Moon-Earth line, but are slightly ahead (inertia). So near bulge pulls Moon forward about 6.7% stronger than farther bulge pulls it back (becase the farther one is farther away). Thus Moon accelerates forward and gains angular momentum and Earth slows down (so total momentum remains the same).

As a result each Earth's day is 42 nanosecond longer than the previous one and Moon is receeding about 1.5 inches/year away from Earth.

Follow Ups:

Login to Post
Additional Information
Google
 
Web www.astronomy.net
DayNightLine
About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
Unless otherwise specified, web site content Copyright 1994-2019 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins