August 24, 2009 - Enceladus Erupts onto the Scene

Enceladus Erupts onto the Scene Two hundred and twenty years ago this week, British astronomer Sir William Herschel discovered Enceladus, the sixth largest moon of Saturn. Although its orbital period around Saturn was confirmed by subsequent telescopic observations, little more was learned about Enceladus until the Voyager flyby missions of 1980 and 1981. They showed Enceladus to possess a youthful, highly reflective surface. Because Enceladus is embedded in Saturn’s diffuse E ring, scientists speculated that the moon was the source of the material that comprised the ring. In 2006, that theory was confirmed by the Cassini spacecraft, which discovered water vapor and complex hydrocarbons venting from the geologically active South Polar Region, as seen in this false color image.

Image credit:NASA / JPL / CalTech


Weekly Calendar

August 24-30, 2009

Holidays - Sky Events - Space History

Moon phase Monday 24

Mercury at greatest elongation (27° E)

Moon phase Tuesday 25

1965: President Johnson approves full-scale development of Manned Orbital Laboratory
1966: Apollo-Saturn 202 launched
1981: Voyager 2 flies past Saturn
1989: Voyager 2 flies past Neptune
2003: Spitzer Space Telescope launched

Moon phase Wednesday 26

Moon phase Thursday 27

First Quarter Moon 7:42 am
Antares 0.6° south of Moon

1962: Mariner 2 launched
1984: Teacher In Space program announced
1985: STS-51I Discovery launched

Moon phase Friday 28

1789: William Herschel discovers Enceladus, moon of Saturn
1993: Galileo spacecraft flies by asteroid Ida
2009: STS-128 Discovery launched

Moon phase Saturday 29

Moon phase Sunday 30

1963: Lunar Orbiter program approved by NASA
1983: STS-8 Challenger launched
1984: STS-41D Discovery launched

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