Gerard Kuiper discovers one of Neptune's moons, Nereid.
2
185 years ago, in 1780:
The first binary star system to be discovered, Xi Ursae Majoris, is found by William Herschel.
3
304 years ago, in 1661:
Christiaan Huygens observes the planet Mercury transit the Sun.
250 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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5
4 years ago, in 1961:
Alan Shepard is the first American to be in a suborbital flight around the Earth (Mercury/Freedom 7).
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212 years ago, in 1753:
Charles Messier makes his first documented observation; the Mercury transit of the Sun.
47 years ago, in 1918:
The 72 inch Plaskett telescope at The Dominion Astrophysical Observatory in Saanich, British Columbia sees first light.
This year:
The Lincoln Calibration Sphere 1 (LCS-1), a large aluminium sphere used for radar calibration, launches with the Lincoln Experimental Satellite-2.
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2 years ago, in 1963:
Telstar 2 is launched.
8
3 years ago, in 1962:
The first Atlas-Centaur rocket is launched, but the Centaur stage ruptures at 53 seconds into the flight and disintegrates, taking the Atlas with it.
9
43 years ago, in 1922:
Tthe IAU passes a resolution to formally adopt Annie Jump Cannon's stellar classification system.
This year:
Luna 5 is launched to the Moon.
10
19 years ago, in 1946:
A White Sands modified V-2 rocket reaches 69 miles (111 kms).
This year:
Last contact is made with Explorer 18.
11
184 years ago, in 1781:
The Sombrero Galaxy (M104) is discovered by Pierre Méchain.
12
35 years ago, in 1930:
The first planetarium in the United States, Adler Planetarium in Chicago, is opened to the public.
This year:
Luna 5 crashes into the Moon, instead of a soft landing as planned.
13
232 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.
104 years ago, in 1861:
John Tebbutt of Australia discovers the Great Comet of 1861 (C/1861 J1).
5 years ago, in 1960:
The original Echo 1, a metalized balloon passive-communications satellite, is launched, but the rocket explodes after lift-off.
14
1 year ago, in 1964:
Communications fail for the Venus-bound Zond 1 spacecraft.
15
8 years ago, in 1957:
The first launch of a Soviet R-7 Semyorka leads to an unintended crash 400 km (250 mi) from the launch site.
7 years ago, in 1958:
Sputnik 3 is launched to explore the upper atmosphere and near space.
5 years ago, in 1960:
Korabl-Sputnik 1 (Sputnik 4), the first and unmanned test flight of the Vostok, is launched.
2 years ago, in 1963:
Mercury/Faith 7, the last Mercury mission, orbits the earth 22 times, with astronaut L. Gordon Cooper, Jr.
16
This year:
Telstar 2 is turned off.
17
83 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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19
4 years ago, in 1961:
Venera 1 is the first craft to fly by Venus, though contact is lost.
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21
181 years ago, in 1784:
William Herschel discovers NGC 6287, a globular cluster in the constellation Ophiuchus.
22
181 years ago, in 1784:
William Herschel discovers NGC 6284, a globular cluster in the constellation Ophiuchus.
19 years ago, in 1946:
A White Sands WAC Corporal reaches the then-defined edge of space, 50 miles (80 kms).
23
7 years ago, in 1958:
Explorer 1 makes its final transmission.
24
422 years ago, in 1543:
Nicolaus Copernicus dies at age 70 in Frauenburg, Royal Prussia, Kingdom of Poland.
130 years ago, in 1835:
John Herschel discovers NGC 6325, a globular cluster in the constellation Ophiuchus.
3 years ago, in 1962:
Mercury/Aurora 7 orbits the earth with astronaut Scott M. Carpenter.
25
4 years ago, in 1961:
President Kennedy makes his famous "Moon speech".
This year:
AS-104 (SA-8), is successfully launched, carrying the fourth 'boilerplate' version of the Apollo spacecraft and the second Pegasus micrometeroid detection satellite.
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28
6 years ago, in 1959:
Launched aboard a Jupiter ICBM, Able and Baker became the first monkeys to survive spaceflight.
1 year ago, in 1964:
AS-101 (SA-6), is successfully launched, carrying the first 'boilerplate' version of the Apollo spacecraft.
29
46 years ago, in 1919:
Arthur Eddington confirms Einstein's theory of general relativity during a total solar eclipse.
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30 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 3963 days
