Gerard Kuiper discovers one of Neptune's moons, Nereid.
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175 years ago, in 1780:
The first binary star system to be discovered, Xi Ursae Majoris, is found by William Herschel.
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294 years ago, in 1661:
Christiaan Huygens observes the planet Mercury transit the Sun.
240 years ago, in 1715:
During an eclipse in England, Edmond Halley is the first to report the phenomenon later known as Baily's Beads.
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202 years ago, in 1753:
Charles Messier makes his first documented observation; the Mercury transit of the Sun.
37 years ago, in 1918:
The 72 inch Plaskett telescope at The Dominion Astrophysical Observatory in Saanich, British Columbia sees first light.
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33 years ago, in 1922:
Tthe IAU passes a resolution to formally adopt Annie Jump Cannon's stellar classification system.
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9 years ago, in 1946:
A White Sands modified V-2 rocket reaches 69 miles (111 kms).
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174 years ago, in 1781:
The Sombrero Galaxy (M104) is discovered by Pierre Méchain.
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25 years ago, in 1930:
The first planetarium in the United States, Adler Planetarium in Chicago, is opened to the public.
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222 years ago, in 1733:
Birger Wassenius of Sweden, observing an eclipse near Göteborg, is the first to report prominences visible to the unaided eye; he incorrectly attributes them to the Moon.
94 years ago, in 1861:
John Tebbutt of Australia discovers the Great Comet of 1861 (C/1861 J1).
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73 years ago, in 1882:
On an expedition in Egypt , Dr. Arthur Schuster sees a comet (Tewfik) near the Sun during a total eclipse.
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171 years ago, in 1784:
William Herschel discovers NGC 6287, a globular cluster in the constellation Ophiuchus.
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171 years ago, in 1784:
William Herschel discovers NGC 6284, a globular cluster in the constellation Ophiuchus.
9 years ago, in 1946:
A White Sands WAC Corporal reaches the then-defined edge of space, 50 miles (80 kms).
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412 years ago, in 1543:
Nicolaus Copernicus dies at age 70 in Frauenburg, Royal Prussia, Kingdom of Poland.
120 years ago, in 1835:
John Herschel discovers NGC 6325, a globular cluster in the constellation Ophiuchus.
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36 years ago, in 1919:
Arthur Eddington confirms Einstein's theory of general relativity during a total solar eclipse.
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20 years ago, in 1935:
The David Dunlap Observatory in Richmond Hill, Ontario, housing a 74-inch (1.88 m) reflector telescope (still the largest in Canada), has its official opening .
It's been 3968 days
