The First Planets

Venus was the first planet to be reached by a space probe. In 1962, the U. S. probe Mariner 2 flew within 22,000 miles (35,400 kilometers) of Venus, but the Russians made the first remote-con­trolled landing in 1970, with their probe Venera 7. The U. S. Magellan spacecraft arrived at Venus in 1990. During a four-year stay, it sent back radar images of almost the entire planet surface.

In the 1960s and 1970s, U. S. Mariner probes investigated

О The identical space probes Voyager 1 and 2 continue to travel decades after they were launched. It is hoped that they will continue their journey farther into space. Voyager 1 has already reached the outer edge of the solar system.

the planet Mars as well as Venus and Mercury. Mariner 9, launched in 1971, went into orbit around Mars and sent back the first close-up pictures of the planet. In 1976, the United States land­ed Viking 1 and 2 on Mars.

In November 1996, Mars Global Surveyor became the sixteenth space probe to fly by, orbit, or land on Mars. The following year, 1997, the Pathfinder lander made a touchdown on Mars and released a robot rover named Sojourner. The little solar-powered rover had a spec­trometer to analyze the chemical compo­sition of the Martian soil and a camera to send back pictures of the surface.