Astronomy Picture of the Day
    


Retrograde Mars
<< Yesterday 27.10.2014 Tomorrow >>
Retrograde Mars
Credit & Copyright: Tunç Tezel (TWAN)
Explanation: Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass starting late last year, Mars as usual, loomed large and bright. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Featured here is a series of images digitally stacked so that all of the stars coincide. Here, Mars appears to trace out a narrow loop in the sky. At the center of the loop, Earth passed Mars and the retrograde motion was the highest. Retrograde motion can also be seen for other Solar System planets.

APOD Wall Calendar: Moons and Planets

January
February
March
April
May
June
July
August
September
October
November
December
 < October 2014  >
Mo Tu We Th Fr Sa Su


12345
6789101112
13141516171819
20212223242526
2728293031

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: Mars - retrograde motion
Publications with words: Mars - retrograde motion
See also:
All publications on this topic >>