Sputnik 1 became Earth’s first artificial satellite to go into orbit.
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Two new moons orbiting Uranus were announced in Nature magazine.
Cassini orbiter released the Huygens probe, which successfully landed on Saturn's moon Titan.
All nine planets (including Pluto) lined up with the sun.
Astronomer Richard Walker discovered Saturn's moon, Epimetheus.
The USSR's Luna 15 robotic spacecraft was launched from the Baikonur Cosmodrome in Kazakhstan.
