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Astronomy/if we live on the moon

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Expert: - 4/8/2010


Question
"If we lived on the Moon, how would the position of the Earth change in our sky over time? Would the position of the Earth change in our sky over time? Would the position of the planets from there appear to the eye any different from the motion we see from Earth?"

Answer
Hi Nes,
It wouldn't move. Since the moon keeps its same side toward the Earth, the Earth remains "frozen" in the lunar sky.  In effect, its the "north star" of the moon. On the lunar
equator (earth facing side) the Earth is right overhead; from the limb or polar regions of the moon, the Earth sits right on the horizon.  You could actually calculate where you are on the lunar surface (earth facing side) by comparing the Earth's position in your lunar sky.

No, the other heavenly bodies would 'move' as we see them from the Earth, except instead of circling in 24 hours, since the moon rotates (and revolves) once every 29.6 days, the sky takes 29.6 days to "rotate around" once. Everything else, the sun, the planets, the stars... are just as we see them, except in very slow motion... 29.6 days instead of 24 hours.  

So the only thing really different, would be the Earth... it just sits there (as long as you don't change your location on the moon) going through it's phases...opposite to the lunar phase that we see from the Earth, while the sky streams behind it, taking 29.6 days to make one
revolution.... basically the sky does just the opposite of the Moon's own motion, just like on the Earth.
Hope this helps,
Clear Skies,
Tom Whiting
Erie, PA USA  

Astronomy

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Tom Whiting

Expertise

Astronomy has been my hobby/pasttime for over 50 years.  Currently own 3 telescopes, the largest of which is a 30 inch Newtonian truss Dob that is portable.I taught Astronomy/Meteorology at the University Level for 13 years before retiring in 1995. Being retired and home most of the time, I am able to answer all questions relatively quickly, unless it's a new moon weekend with good observing conditions.  No astrology questions please, or questions about alleged UFO picture identifications.

Experience

Experience: Astronomy has been my hobby and study for over 50 years. We currently now own a 30 inch portable telescope (Updated - Pennsylvania`s largest portable telescope). It can be seen on our website at:http://www.velocity.net/~bwhiting and also attend several regional starparties during the year, and have been on 5 total solar eclipse expeditions.

Organizations: President, Erie County Mobile Observers Group for over 15 years.

Publications: Wrote the "Over Erie Skies" newspaper article in our local newspaper for 11 years (1975-86).

Education: Masters Degree- Taught at the University level for 13 years. Retired 20 years -USAF Pilot - KC-135 with 180 combat missions;  Also Eagle Scout, Philmont staff 2 Yrs, Order of Arrow Lodge Chief, Ham Radio (inactive).

Awards: two discoveries: The mini-coathanger asterism in Ursa Minor (the little dipper) And the mini-ladle- another asterism in the bowl of Ursa Minor. Clients: Currently President of the ECMOG as mentioned above.

Education/Credentials
BS  Metallurgical Engineering Grove City College, PAMaster's Degree, Gannon University, Erie, PA Also retired USAF pilot, 20 years.

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