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June 5, 2017 - To Know Neptune

To Know Neptune  Born 205 years ago this week, Johann Gottfried Galle was a German astronomer who, in 1846, became the first person to observe Neptune and know it was a planet. Prompted by calculations made by Urbain Leverrier, and aided by Heinrich Louis d’Arrest, Galle identified the planet where Leverrier calculated it would be. Neptune, seen here in an image taken by the Voyager 2 spacecraft in 1989, is thus unique because it is the first planet whose existence was predicted before it was observed. Galle also discovered three comets, compiled a catalogue of 414 comets, and proposed a method of accurately calculating the distance to the Sun. Galle, who lived to the ripe old age of 98, was honored by having two craters named after him, one on the Moon and the other on Mars.

Image credit: NASA / JPL

Weekly Calendar

June 5-11, 2017

Holidays - Sky Events - Space History

 

Moon phase Monday 5

Ceres in conjunction with Sun

1819: John Couch Adams born
1989: Voyager 2 begins regular observations of Neptune
1991: STS-40 Columbia launched
2002: STS-111 Endeavour launched

Moon phase Tuesday 6

1932: Dave Scott born
1971: Soyuz 11 launched, first crew to occupy Salyut 1 space station
1983: Venera 16 launched

Moon phase Wednesday 7

1992: Extreme Ultraviolet Explorer launched
2011Soyuz TMA-02M launched carrying ISS Expedition 28/29 crew

Moon phase Thursday 8

Moon at apogee

1625: Giovanni Cassini born
1959: First X-15 unpowered glide test
1975: Venera 9 launched
2007: STS-117 Atlantis launched

Moon phase Friday 9

Full Moon 9:10 AM ET
Saturn 3° south of Moon

1812: Johann Gottfried Galle born

Moon phase Saturday 10

Jupiter appears stationary

1985: Vega 1 deploys lander and balloon on Venus
2003: Mars rover Spirit launched

Moon phase Sunday 11

Trinity Sunday

2008: Fermi Gamma-Ray Telescope launched
2013: Shenzhou 10 launched, China's fifth human spaceflight mission

Suggestions for new history dates or better links? Corrections for errors on this page? Please e-mail me.