In 1962, the Mariner II space probe began sending back to Earth man's first information from another planet, Venus.

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In 1969, the U.S. space probe "Mariner Seven" flew by Mars, sending back photographs and scientific data.

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In 1971, the American space probe "Mariner Nine" blasted off from Cape Kennedy, Florida, on a journey to Mars.

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It includes, for example, the case of Mariner 1, an unmanned Venus probe launched in July 1962.

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So it was to everybody's disappointment that Mariner 4, the first space probe to fly past Mars (in 1965), revealed a place with a surface that appeared to have been static for billions of years.

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