Caroline Herschel discovers her first comet, Comet C/1786 P1 (Herschel).
2
828 years ago, in 1133:
King Henry's Eclipse occurs over England, with totality lasting for over four minutes, and coinciding with the death of King Henry I.
3
2392 years ago, in -431:
The oldest European record of a verifiable solar eclipse (annular) is given by the Greek historian Thucydides.
365 years ago, in 1596:
David Fabricius discovers the first known periodic variable star, Mira, in the constellation of Cetus.
4
5
6
This year:
Aboard Vostok 2, Gherman Titov is the second person to orbit the Earth, orbiting 17 times.
7
2 years ago, in 1959:
Explorer 6 is launched to study micrometeorites, cosmic rays, etc; it also takes the first photograph of Earth from orbit.
This year:
Vostok 2 lands back on Earth after a day in orbit.
8
9
10
188 years ago, in 1773:
Charles Messier first observes NGC 205, also known in later years as M110.
11
12
84 years ago, in 1877:
Asaph Hall, Sr., an American astronomer, discovers the first of Mars' moons, Deimos.
1 year ago, in 1960:
Echo 1A, a metalized balloon passive-communications satellite, is launched.
13
63 years ago, in 1898:
433 Eros, the first discovered and second-largest near-Earth asteroid, is discovered by the German astronomer Carl Gustav Witt at the Berlin Urania Observatory.
31 years ago, in 1930:
A meteor explodes in an air burst over the Curuca River area in Brazil.
14
164 years ago, in 1797:
Caroline Herschel and Eugene Bouvard independently discover Comet C/1797 P1 (Bouvard-Herschel).
15
16
This year:
Explorer 12 is launched to measure the Solar Wind, Cosmic Rays, and interplanetary magnetic fields.
17
28 years ago, in 1933:
Under the leadership of Sergey Korolev, the Group for the Study of Reactive Motion (GIRD) launches the first Soviet liquid-fueled rocket.
3 years ago, in 1958:
Able 1 (Pioneer 0) is the world's first craft intended for launch out of Earth's orbit, but explodes 77 seconds after lift-off.
18
93 years ago, in 1868:
French astronomer Pierre Jules César Janssen discovers an unknown element, now known as helium, in the spectrum of the sun during a total eclipse.
84 years ago, in 1877:
Asaph Hall, Sr., an American astronomer, discovers the second of Mars' moons, Phobos.
19
3 years ago, in 1958:
Thomas Keith Glennan becomes the first Administrator of NASA.
1 year ago, in 1960:
Korabl-Sputnik 2 (Sputnik 5) is the first to return plants and animals (2 dogs; Belka and Strelka, 2 rats & 40 mice) alive from Earth orbit.
20
76 years ago, in 1885:
Ernst Hartwig, at the Dorpat Observatory in Estonia, discovers supernova SN 1885A in Andromeda, the first Type Ia detected outside our galaxy.
21
4 years ago, in 1957:
A Soviet R-7 Semyorka is launched and flies 6000 km (3700 mi) to become the world's first ICBM.
22
23
This year:
Ranger 1 is launched to be placed in an eliptical orbit around the Moon, but burns up in low orbit four days later.
24
3 years ago, in 1958:
Explorer 5 is launched, but fails when the rocket's first stage collides with its second stage after separation.
This year:
Last contact is made with Explorer 7.
25
96 years ago, in 1865:
The Shergotty meteorite, the first example of the shergottite Mars meteorite family, falls to Earth in Shergotty (now Sherghati) in the Gaya district, India.
This year:
Explorer 13 is launched to study the effects of micrometeoroids on the spacecraft systems, but enters a lower than planned orbit.
26
27
188 years ago, in 1773:
Caroline Herschel independently discovers NGC 205, also known in later years as M110.
28
172 years ago, in 1789:
William Herschel discovers a moon of Saturn, Enceladus.
This year:
After just over two days in orbit, Explorer 13 reenters the Earth's atmosphere and burns up.
29
30
31
29 years ago, in 1932:
G. G. Cillié of the United Kingdom and Donald H. Menzel of the United States use eclipse spectra to show that the Sun's corona has a higher temperature than the photosphere.
11 years ago, in 1950:
The first mouse is sent into space aboard a U.S. launched V-2, but dies when the rocket disintegrates due to parachute failure.
It's been 3965 days
