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Pioneer 11  von Professor aus der Kategorie Freier Text - Wissenschaft, Technik |
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Pioneer 11 -------------------------------------------------------------------------------- Launched on April 5, 1973, flew past Jupiter (December 2, 1974) and became the first spacecraft to rendezvous with Saturn (September 1, 1979). The last communication was received from the probe on November 30, 1995; its electric power source exhausted, it could no longer operate any of its experiments or point its antenna toward Earth. Pioneer 11 is headed in the direction of Aquila and may pass relatively near one of the stars in that constellation in about 4 million years. On a shorter time scale, Pioneer 11 will achieve its first stellar encounter of sorts when it passes about 1.65 light-years (0.51 parsec) from the red dwarf AC +79° 3888 in the year 42,405 A.D. At present, AC +79° 3888 is 16.6 light-years (5.1 parsecs) from the Sun, but is approaching so rapidly that by 40,598 A.D. it will be just under 3 light-years (0.9 parsec) away - roughly the same distance that Pioneer 11 will be from the Sun at that time. At the start of 1999, Pioneer was approximately 50 astronomical units (7.5 billion km, 4.7 billion miles) from the Sun. | ||||||||||
