Credit & Copyright: NASA/JPL/Cornell/ASU/TAMU
Explanation:
Staring up into the martian sky, the
Opportunity rover
captured an image at 11:02 AM local mean
time nearly every 3rd sol, or martian day, for 1 martian year.
Of course, the result is this
martian analemma,
a curve tracing the Sun's motion through the
sky in the course of a year (668 sols)
on
the Red Planet.
Spanning Earth dates from July, 16, 2006 to June 2, 2008 the images
are shown composited in
this zenith-centered, fisheye projection.
North is at the top surrounded by a
panoramic sky and landscape made in
late 2007 from inside Victoria crater.
The tinted martian sky is blacked
out around the analemma images to clearly show the Sun's positions.
Unlike Earth's figure-8-shaped analemma,
Mars'
analemma is pear-shaped, because of its similar axial tilt
but more elliptical orbit.
When Mars is farther from the Sun, the Sun progresses slowly in
the martian sky creating the pointy top of the curve.
When close to the Sun and moving quickly, the apparent solar motion
is stretched into the rounded bottom.
For several sols some of the frames are missing due to
rover operations and dust storms.
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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: analemma
Publications with words: analemma
See also: