· Get a Cloudy Nights T-Shirt · Submit a Review / Article Click here if you are having trouble logging into the forums Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Speciality Forums >> Science! Astronomy & Space Exploration, and Others Previous   Index   Next   Threaded   Pages: 1 Brian Albin Seeker Reged: 08/22/06 Loc: Western Oregon Earth Orbit?       #5596836 - 12/30/12 07:51 PM Edit   Reply   Quote Quick Reply   I have read that while Earth’s Moon orbits around the Earth, a more precise understanding is that Earth and it’s Moon each orbit around a shared point somewhere between the centers of the two bodies. In this case the point is so much closer to the center of Earth than to the center of the Moon that it is inside the globe of the Earth. The Moon goes once around this point in a month. How long does it take the center of the Earth to make an orbit around this point? Post Extras:       GlennLeDrew Postmaster Reged: 06/18/08 Loc: Ottawa, Ontario, Canada Re: Earth Orbit? [Re: Brian Albin]       #5596842 - 12/30/12 07:55 PM Edit   Reply   Quote Quick Reply   The same period as for the Moon--both bodies' center of mass lie on opposite sides of the barycenter of the system. Post Extras:       Brian Albin Seeker Reged: 08/22/06 Loc: Western Oregon Re: Earth Orbit? [Re: GlennLeDrew]       #5596844 - 12/30/12 07:56 PM Edit   Reply   Quote Quick Reply   Thanks, Glenn. Post Extras:       Qwickdraw sage Reged: 03/03/12 Loc: Ann Arbor, Mi Re: Earth Orbit? [Re: Brian Albin]       #5598306 - 12/31/12 04:26 PM Edit   Reply   Quote Quick Reply   Here is a very good explanation of the physics of it. web page Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 4 registered and 10 anonymous users are browsing this forum. Moderator:  LivingNDixie, Jarad, WaterMaster  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 294 Jump to *Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Celestial Events*General Astronomy* -----   Beginners Forum   General Observing and Astronomy   Outreach   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning and Intermediate Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   NEO   Planetary and Solar System Observing   Lunar Observing   Deep Sky Observing   Double Star Observing   Solar   Variable Star Observing and Radio Astronomy*Telescope Specific Forums* -----   Celestron NexStar    NexStar GPS / CPC Telescopes   Questar Forum   Meade ACF/RCX / LX / GPS    Meade ETX*Speciality Forums* -----   Arizona Science and Astronomy Expo   NEAF (Northeast Astronomy Forum) and NEAIC (Northeast Astro Imaging Conference)   AstroArt   Astronomy Clubs and Star Parties   Astronomy Software & Computers   AstroWebsites   Science! Astronomy & Space Exploration, and Others   Space Rocks   Stellar Media*Swap and Shop* -----   Shop and Swap Audio Components*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements*International Year of Astronomy 2009 - Forums are now closed.* -----   IYA Archive Info CN Forums Home

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