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
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
Tuesday 6
1932: Dave Scott born
1971: Soyuz 11 launched, first crew to occupy Salyut 1 space station
1983: Venera 16 launched
Wednesday 7
1992: Extreme Ultraviolet Explorer launched
2011: Soyuz TMA-02M launched carrying ISS Expedition 28/29 crew
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
Friday 9
Full Moon 9:10 AM ET
Saturn 3° south of Moon
1812: Johann Gottfried Galle born
Saturday 10
Jupiter appears stationary
1985: Vega 1 deploys lander and balloon on Venus
2003: Mars rover Spirit launched
Sunday 11
Trinity Sunday
2008: Fermi Gamma-Ray Telescope launched
2013: Shenzhou 10 launched, China's fifth human spaceflight mission