On May 30, 1971, the National Aeronautics and Space Administration (NASA) launched an unmanned space probe called Mariner 9 from Cape Canaveral, Florida. Mariner 9 carried equipment that would send images and other data back to Earth after the spacecraft reached its target—orbit around Mars. Mariner 9 reached the Red Planet more than five months later.Mariner 9, Mars' first artificial satellite, spent nearly one year in orbit. It sent back thousands of images: enormous volcanoes, huge canyons, and even evidence of very old riverbeds. Mariner 9 also sent the first close-up images of the two Martian moons, Phobos and Deimos.The Mariner 9 mission was a new way to explore the solar system. Instead of flying by a planet, the space probe orbited around it to get more detailed information. Mariner 9 was a very successful mission, and it prompted many later missions to Mars.
Term Part of Speech Definition Encyclopedic Entry artificial satellite Noun
object launched into orbit.
deep, narrow valley with steep sides.
Encyclopedic Entry: canyon data Plural Noun
(singular: datum) information collected during a scientific study.
tools and materials to perform a task or function.
natural satellite of a planet.
Encyclopedic Entry: moon NASA Noun
(National Aeronautics and Space Administration) the U.S. space agency, whose mission statement is "To reach for new heights and reveal the unknown so that what we do and learn will benefit all humankind."
path of one object around a more massive object.
large, spherical celestial body that regularly rotates around a star.
Encyclopedic Entry: planet solar system Noun
the sun and the planets, asteroids, comets, and other bodies that orbit around it.
vehicle designed for travel outside Earth's atmosphere.
space probe Noun
set of scientific instruments and tools launched from Earth to study the atmosphere and composition of space and other planets, moons, or celestial bodies.
lacking the physical presence of a person.
an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.
Encyclopedic Entry: Plate Tectonics and Volcanic Activity