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Mars is about half the
size of our planet, Earth. It's thin atmosphere is slowly being blown away
by the sun's solar wind. However, its atmosphere forms clouds, and
sometimes supports planet-wide dust storms.
ExplorationsThe USSR in May 1971 launched Mars 2 and 3, two probes
that crash-landed on Mars but In the US programme, Mariner 4, launched in
November 1964, flew past Mars in July 1965 and transmitted to Earth the
first close-up photographs of the Martian surface, which revealed the
presence of craters. It was followed, in 1969, by Mariners 6 and 7, which
also flew past the planet and added to the previous data. Then, in May
1971, Mariner 9 was launched. It orbited Mars from November 1971 to
October 1972, and transmitted enough photographs for an almost complete
map of the planet. In August and September 1975, Vikings 1 and 2 began an
11-month journey to Mars. Each spacecraft carried a lander equipped with
life-detecting and chemical laboratories, two colour television cameras,
weather and seismographic instruments, and a 3-m (10-ft) retractable claw
designed to be manipulated from the Earth. Both functioned well for
several years. After the loss of the Mars Observer spacecraft in 1995, US
exploration of Mars resumed in 1997 when two spacecraft, the Mars Global
Surveyor orbiter and the Mars Pathfinder lander, reached the planet and
began successful missions. Pathfinder included a small rover, named
Sojourner, which investigated the area around the lander
[Top] Unique CharacteristicsMars is the most Earth-like planet in the solar system
(except for in size and therefore surface gravity; Venus takes the cake
for that characteristic). Because of this, several scientists believe
that, if done correctly, Mars can be terra formed into a planet
inhabitable by humans. Mars' SatelliteWhen most people think of a moon, they think of the
relatively large whitish globe that they see at night, and sometimes
during the day. While this is a moon, it is not typical of moons in the
solar system. In fact, Earth has the largest moon in the solar system,
relative to the planet's size, if you don't include Pluto. Most other
moons are much smaller. [Top]
Unlike the planet itself, Mars' moons have not been known
since antiquity. Rather, they were discovered in 1877 by a keen-eyed U.S.
astronomer in Washington, D.C. In a hazy August evening, Professor of
Mathematics in the U.S. Navy Corps of Mathematics, Asaph Hall, was
studying Mars with the 26 inch "Great Equatorial" telescope at the U.S.
Naval Observatory with his assistant, George Anderson. [Top]
Mars' moons are probably not native to Mars. Most likely, they are asteroids that were captured by Mars' gravity, and could not escape. Besides their small size hinting at this, the fact that their orbits have high eccentricity - they deviate from a perfect circle - than most moons suggests that they did not originate around the planet. [Top] External Links
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transmitted data briefly. In August 1973, it launched Mars 4, 5, 6, and 7,
but various technical malfunctions plagued all these missions. In 1988 the
USSR sent two probes, Phobos 1 and 2, to land on the Martian moon Phobos;
the first was lost through human error, and the second dropped out of
radio contact.