Planet Timeline of Events

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Planet

A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science, mythology, and religion...

Timeline of Events

1612

12.28.1612

Galileo Galilei becomes the first astronomer to observe the planet Neptune, although he mistakenly catalogued it as a fixed star.

1915

3.19.1915

Pluto is photographed for the first time but is not recognized as a planet.

1965

11.16.1965

Venera program: The Soviet Union launches the Venera 3 space probe toward Venus, the first spacecraft to reach the surface of another planet.

1966

3.1.1966

Venera 3 Soviet space probe crashes on Venus becoming the first spacecraft to land on another planet's surface.

1967

6.12.1967

Venera program: Venera 4 is launched (it will become the first space probe to enter another planet's atmosphere and successfully return data).

1970

8.17.1970

Venera Program: Venera 7 launched. It will later become the first spacecraft to successfully transmit data from the surface of another planet (Venus).

1972

3.2.1972

The Pioneer 10 space probe is launched from Cape Canaveral, Florida with a mission to explore the outer planets.

1979

9.1.1979

The American space probe ''Pioneer 11'' becomes the first spacecraft to visit Saturn when it passes the planet at a distance of 21,000 km.

1995

10.6.1995

51 Pegasi is discovered to be the first major star apart from the Sun to have a planet (and extrasolar planet) orbiting around it.