Objects - Mars

Favorite Obects
& Observing Tips:

Mars

[NASA photo]

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Facts Observing Notes Exploratory Missions Mythology, etc.

Mars Facts:
SIZE	4,219 miles in diameter, approximately 1/2 the size of Earth. Because there are no oceans or lakes on Mars the landmass of the planet is about the same as Earth's.
DISTANCE FROM SUN:	128-155 million miles (mean: 142 million miles / 229 million km)
DISTANCE FROM EARTH:	34,000,000 miles during close opposition. Mars will be this close during the 2003 opposition, the closest in 60,000 years. During the 2001 opposition Mars was much further away, 42,000,000 miles.
LENGTH OF YEAR:	687 days (nearly 2 years)
LENGTH OF DAY:	24 hours 38 minutes, almost the same as Earth's
ATMOSPHERE:	Pressure: 7-9 millibars (Earth: 1014 millibars) Composition: 95% carbon dioxide; 3% nitrogen (Earth: 78% nitrogen, 21% oxygen). Visibility: Atmosphere is usually clear except for dust-storms which can sometimes cover the entire planet.
TEMPERATURE:	65% F. daytime, -130 at night. However, the daytime high is much colder 5' from the surface, only 15% F.
GEOLOGY:	The makeup of Mars is very similar to Earth's. The red color is due to a large amount of iron oxide (rust). The geologic features of Mars are varied...with many volcanoes, great valleys and enormous asteroid impact craters. Polar caps are a mixture of carbon dioxide ice and water ice, and expand and contract with Martian seasons
MOONS:	Phobos (20 mile diameter) and Deimos (10 mile diameter) Irregular in shape, and thought to be captured asteroids. They orbit very rapidly (Phobos in 7 hours) and would look like bright stars from the Martian surface.

Mars: Observing Notes

Evening planet in Taurus (March/April) & Gemini (May/June) in 2004, then disappears into daytime sky.
Mars is the only planet with surface features visible in a telecope. Every few years, we come close enough (at opposition) to glimpse details such as the southern ice cap and the dark "maria" plains. However, much of the time the round shape and orangy color are the best we can do.
Mars is distinctly red in color; right now (Spring, 2004) it is easily confused with the nearby red star Aldebaran in Taurus.
When it's close enough for detail, the green filter helps bring out the ice cap in good seeing conditions.
"Canals" - lines drawn by Schiaparelli in 1877, observing with a 9" refractor - he called them "canali" meaning "channels" - which was translated as "canals" and led to widespread speculation on Martian civilizations. Though many people "saw" them, they proved to be optical illusions - literally in the eye of the beholder.

Filters:
(from the information provided with Celestron filter packages)The following filters all say: "Reduces the light from the blue and green areas which darkens the maria, oases and canal markings while lightening the orangish desert regions. Also sharpens the boundaries of yellow dust clouds."

Deep Yellow (#12, 74% T)
Deep Yellow (#15, 67% T)
Orange (#21, 46% T)
Light Red (#23a, 25% T)

Other filters:

Yellow (#8, 83% T): Improves the Martian maria by reducing the scattered light from the blue areas while allowing passage of more green light for studying yellowish dust clouds.
Red (#25, 14% T): ideal for observation of the polar ice caps and features on the Martian surface. Also sharpens the boundaries of yellow dust clouds.
Blue (#38a, 17% T): useful during the violet clearing and for studying surface features. Also helpful in studying localized clouds and ice fogs.
Violet (#47, 3% T): useful for detecting high clouds and haze over the Martian polar caps. Very useful during the violet clearing.
Light Green (#56, 53% T): Excellent for increased contrast of Martian polar caps, low clouds and yellowish dust storms
Green (#58, 24% T): Excellent for increased contrast of Martian polar caps, low clouds and yellowish dust storms
Light Blue (#80a, 30% T): Very useful during the violet clearing. Helpful in the study of surface features and polar caps.
Pale Blue (#82a, 73% T): Very useful during the violet clearing. Helpful in the study of surface features and polar caps.

Exploratory missions:
(information on NASA Mars programs: marsprogram.jpl.nasa.gov

First fly-by - Mariner 4 (7/14/65)
First orbiter - Mariner 9 (11/13/71)
First landers: Viking1 (7/20/76) & Viking 2 (9/3/76) - designed to detect evidence of life; none found.
Pathfinder - landed on Mars 7/4/97
Mars Exploration Rovers "Spirit" & "Opportunity" (Jan 2004) - marsrovers.jpl.nasa.gov

Mythology:

Bibliography:

MARS: Discovering the Secrets of the Red Planet, by Paul Raeburn, Pub. National Geographic 1998. See p. 225.

THE SMITHSONIAN BOOK OF MARS, by Joseph M. Boyce, printed in China 2002.

THE CASE FOR MARS: The Plan to Settle the Red Planet and Why We Must, by Dr. Robert Zubrin, Pub The Free Press, 1996.