Stargazing on Mars

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Top Page
Stargazing on MARS
Your imaginary observatory location, 360 degrees
unobstructed view, True dark sky.
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Environment on Mars

• Thin atmosphere, no industrial smog, no light
  pollution,
• Excellent seeing and transparency (in absence of
  sand storms, etc.).

• Average temperature on Mars is -63ºC/-81.4ºF
• Atmosphere is composed of 95.32 carbon dioxid
  and 7.2 nitrogen
• Average atmospheric pressure is 0.007 bars
  (about 1/100th of Earth)
• Gravity is 0.379 of Earth's.
• A year on Mars is 1.881x of Earth, a day is
  about 40 minutes longer.

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Different Constellations?
Its only a small step to Mars, but no giant leap
into space. Therefore, the constellations appear
like as seen from Earth.
Mars Rover Spirits image of Orion as viewed from
15 deg southern latitude on Mars.
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Marss Polar Axis

• The orientation of Marss axis is different from
  Earth,
• Mars has no obvious Pole Stars,
• Inclination to ecliptic is 1.85º same zodiac
  constellations,
• but different equinoxes and solstices,
• Mars, too, is subjected to precession and axial
  tilt variation.

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Observing the Martian Moons
Moon Orbits to-scale
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Observing the Martian Moons
Apparent Angular Sizes
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Observing the Martian Moons
Fact Sheet
Phobos (fear)
Deimos (panic)
Image Viking 2 Orbiter
Image Viking Orbiter
Dimensions Surface distance Center
distance Apparent size Visual magnitude Orbit
period Axial rotation of Mars 1.026 days
27 x 22 x 18 km 5,980 km 9,378 km 12.58 -9mv
max. 0.32 days rises in the west
15 x 12 x 11 km 20,060 km 23,459 km 2.43 -5.5mv
max. 1.26 days
In the meridian on 45º latitude, measured on
longest axis. Angular size variations Phobos
45, Deimos 1.8 to 2.6
Image Phobos-2, Feb 28, 1989
Image Viking 2, h30km, 1.2km wide
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Observing Mars from its Moons
From Phobos Simulated view on Valles
Marineris FOV 120º Mars angular size 42.5º
(85x the full Earth moon)
From Deimos Simulated view on the Hellas
region FOV 120º Mars angular size 16.7º
(33x the full Earth moon)
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From Moon to Moon
Visibility Condition
Phobos 8.2º E/W elongation Deimos 20º E/W
elongation
Apparent Sizes

• An exciting performance of fast changes,
• Observing Phobos from Deimos is most dynamic
• Phobos - Deimos minimum distance is 14,081km,
• Phobos - Deimos maximum distance is 32,837km.

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Solar Eclipses on Mars

• Phobos Eclipse
• Mars Rover Opportunity
• On March 10, 2004
• Sun size is 2/3rd
• Phoboss is half of Earth Moon

• Deimos Eclipse
• Mars Rover Opportunity
• On sol 39 of its mission
• Sun size is 2/3rd
• Deimos size is half of Phobos

• Eclipses occur several times a day
• No total eclipses on Mars
• Less spectacular than on Earth

Phobos eclipse shadow Mars Global Surveyor.
August 26, 1999 over Western Xanthe Terra. 250km
(155mi across)
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Observing Earth from Mars

• Earth is an inner planet,
• Shows phases like Venus/Mercury,
• Mean greatest elongation is 41º,
• Earth transits observable but rare.
• (last May 11, 1984 next Nov 10, 2084)

Venus transit in 2004. Courtesy K. Spencer.
Mars Global Surveyor. May 8, 2003 1300 UTC

• Earth of the Past
• Earth-Mars light time varies between
• 3 and 22 minutes.
• In 22 minutes Earth rotates 5.5º
• towards East (1º in 4 minutes).

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Imaging on Mars
Our Mars Observatory
Mars Rover Spirit
Spirits two panoramic CCD cameras.
Spirits field of view

• Location Gusev Crater, 15º south of equator
• Mounting altazimuth, no tracking
• Pixel area 1,024 x 1,024 pixels
• Field of view 16.8º
• Resolution 59 per pixel
• Equivalent 35mm SLR with 125mm lens
• Cost 400 million US, excluding shipment

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Imaging on Mars
Orion
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Imaging on Mars
Phobos and Deimos
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Imaging on Mars
Phobos and Deimos
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Imaging on Mars
Phobos Lunar Eclipse
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Imaging on Mars
South Celestial Pole Region
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Back to Earth Thank You!