Location and Orbit
Atmosphere and Magnetosphere
Missions to Mars
References & Links
Life on Mars?
Missions to Mars
The second generation of Soviet missions included the probes Phobos 1 and 2, launched in 1988 towards the Martian moon of the same name. Phobos 1 was lost in space, but Phobos 2 successfully sent information on Phobos's and Mars's surface composition. The last probe, Mars '96, lifted off in November 1996 but came hurtling back to Earth.
The United States has had more success with its programs. The Mariner program was launched in the early 1960's, and though not all of the program's probes examined Mars or its moons, many returned servicable information. Mariner 4 (November 1964) took the first close-up photographs of the planet. Its high-resolution pictures dispersed the ideas of an advanced Martian civilization. Mariner 6 (February 1969) and Mariner 7 (March 1969) supplied more detailed images of the surface and measured the gravitational acceleration and planetary atmosphere. Mariner 9 (May 1971) revealed much of Martian topography, including volcanoes, channels, and canyons. The US Viking Program of the 1970's could arguably be the most extensive and successful mission to Mars yet. From its two probes come much of the most current data available to scientists today. Each probe had an orbiter and lander. The orbiters mapped the Martian surface and studied the geology and chemistry of the terrain. The landers measured the composition of the surface and searched for life. Vikings 1 and 2 carried out three biological experiments on the Martian soil, the results of which puzzle scientists even today.
The US Mars Observer, launched in September of 1992, was lost before reaching Mars. Its near-twin Mars Global Surveyor 96 went online November 1996. The probe entered orbit around Mars in 1997 and monitored the planet's weather and measured its surface composition and topography. It is currently in orbit around the Red Planet, coming within 120 km. The Mars Global Surveyor 96 gave NASA the first 3-D map of Mars using its Mars Orbiter Laser Altimeter (MOLA). It clearly shows erosion patterns that may have been the result of flowing water in the past.
Windblow dunes spot the planet, the brighter of which consist of sulfates and the darker of which consist of fine grains of lava. The probe also uncovered massive plates of solid lava formed by ancient volcanic activity in the Elysium Basin. An extensive canyon system was also discovered. The Valles Marineris is the largest known canyon in our solar system.
The Mars Pathfinder was sent in December of 1996 to study Martian weather conditions with its lander. The rover named Sojourner trekked along the surface and shot photographs. It also analyzed 15 nearby rocks. Two major probes constitute the Mars Surveyor 98 program. The Mars Climate Orbiter launched in December of 1998 but was lost in September of 1999. This misfortune was attributed to a miscommunication between NASA's Jet Propulsion Laboratory (JPL) and the Lockheed Martin Corporation that built it. Allegedly, Lockheed supplied figures in English units, but NASA assumed them to be standard SI units. The Mars Polar Lander of January 1999 suffered an unknown malfunction in December of 1999.
Japan is the only other country to have launched any missions to Mars. It launched the Nozomi in July of 1998 which is scheduled to arrive Mars in 2003. The mission objective is to study the atmosphere. INTERMARSNET is an international program planned by the European Space Agency (ESA) and NASA to study Mars.