Summary of Observed Motions

of the Sun, Moon and Planets

DAILY MOTION

ALL: East to West with respect to the HORIZON

Sun, Moon, Planets, Stars -- all RISE above the Horizon toward the EAST, SET below the horizon toward the WEST in approximately 12 hours

Cause: Earth spinning on its axis toward the EAST.

MONTHLY MOTION

MOON moves toward EAST with respect to STARS during a month.

MOON rises 50 min later each day.

Cause: Moon orbits about the Earth toward the EAST.

ANNUAL MOTION

SUN moves toward EAST with respect to the STARS during the year.

See different stars at different Seasons: Orion in winter, Leo in spring, Virgo in summer and Cygnus in fall.

PLANETS move toward EAST with respect to the STARS during the year,

except when passing (retrograde motion toward west).

Cause: Earth and Planets orbit about the Sun toward the EAST. Retrograde Motion occurs when inner planet, going faster, overtakes and passes an outer planet.

Sky Outline
Bob Stein's home page, email: stein@pa.msu.edu