Viking 1 leaves for Mars.
NASA

Viking

The Viking missions to Mars were part of a series of U.S. efforts to explore and better understand the red planet. Each Viking spacecraft consisted of an orbiter and lander. The landers were sterilized before launch to prevent contamination of Mars with organisms from Earth. Their objectives were to obtain highly detailed pictures of the Martian surface, learn about its composition, and search for life.

Viking 1 was launched on Aug. 20, 1975, followed later that year on Sep. 9 by Viking 2. The spacecraft deployed their landers using parachutes and retro-thrusters which prevented a dangerous high-speed impact. Viking 1 landed on the western slope of Chryse Planitia (the Plains of Gold) at 22.3 degrees N latitude, 48.0 degrees longitude. Viking 2 landed on Utopia Planitia; 47.6 degrees N latitude, 225.7 degrees W. longitude. Over the next four years, the orbiters mapped 97% of the Martian surface and relayed information from the landers back to Earth. They also collected data which suggests that moons Phobos and Demios may have originally been asteroids captured by Mars' gravity.

The Viking landers monitored Martian weather, including regular dust storms and temperature changes, and returned high-resolution color photos which revealed interesting geologic features such as volcanoes and canyons. Their analysis of Mars' soil found no evidence of life, instead showing that organic molecules are even more scarce there than on our Moon. The Viking missions did discover water in both solid and vapor form, suggesting that life may have existed on the planet many years ago.

Some of the data returned from these two spacecraft are shown in the image archive below. With this data, scientists began to make educated guesses about what the interior, surface history, and evolution of Mars must be.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

The Viking Missions

The Viking I and Viking 2 missions were designed to both orbit Mars and land and make exploratory observations on the planet's surface. At this stage in the history of the exploration of Mars, scientists...more

Hubble Space Telescope

The Hubble Space Telescope (HST) was one of the most important exploration tools of the past two decades, and will continue to serve as a great resource well into the new millennium. The HST is credited...more

Apollo 11

Driven by a recent surge in space research, the Apollo program hoped to add to the accomplishments of the Lunar Orbiter and Surveyor missions of the late 1960's. Apollo 11 was the first mission to succeed...more

Apollo 12

Apollo 12 survived a lightning strike during its launch on Nov. 14, 1969, and arrived at the Moon three days later. Astronauts Charles Conrad and Alan Bean descended to the surface, while Richard Gordon...more

Apollo 15

Apollo 15 marked the start of a new series of missions from the Apollo space program, each capable of exploring more lunar terrain than ever before. Launched on July 26, 1971, Apollo 15 reached the Moon...more

Deep Impact Mission

NASA chose Deep Impact to be part of a special series called the Discovery Program on July 7, 1999. In May 2001, Deep Impact was given the "go" from NASA to start with mission development. Deep Impact...more

Galileo

The Galileo spacecraft was launched on October 19, 1989. Galileo had two parts: an orbiter and a descent probe that parachuted into Jupiter's atmosphere. Galileo's primary mission was to explore the Jovian...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA