Background Info

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.

Vocabulary

Term Part of Speech Definition Encyclopedic Entry

artificial satellite

Noun

object launched into orbit.

canyon

Noun

deep, narrow valley with steep sides.

Encyclopedic Entry: canyon

data

Plural Noun

(singular: datum) information collected during a scientific study.

equipment

Noun

tools and materials to perform a task or function.

moon

Noun

natural satellite of a planet.

Encyclopedic Entry: moon

NASA

Noun

(acronym for National Aeronautics and Space Administration) U.S. agency responsible for space research and systems.

orbit

Noun

path of one object around a more massive object.

planet

Noun

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.

spacecraft

Noun

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.

unmanned

Adjective

lacking the physical presence of a person.

volcano

Noun

an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.

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Editor

Caryl-Sue, National Geographic Society

Producer

Mary Crooks, National Geographic Society

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