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September 10, 2018 - Oddball Moon

Oddball Moon  Hyperion is one of the oddest moons in the solar system. The largest of Saturn’s irregular, non-spherical moons, Hyperion is 410 km (255 mi) long, and 220 km (137 mi) at its narrowest width. Its odd potato shape suggests Hyperion is a remnant of a larger moon that was destroyed by a major impact. It is about half as dense as water, which means that Hyperion could be comprised of chunks of water ice with significant voids, or that lighter materials (frozen methane or carbon dioxide) could make up part of the moon. Hyperion rotates in a tumbling chaotic way through space as it orbits Saturn every 21 days. Hyperion was discovered independently by the English astronomer William Lassell, and the American father and son team of William and George Bond, 170 years ago this week.

Image credit: NASA / JPL-Caltech

Weekly Calendar

September 10 - 16, 2018

Holidays - Sky Events - Space History

 

Moon phase Monday 10

1857: James Keeler born
1967: Surveyor 5 lands on Moon
1978: Venera 11 launched
2011: GRAIL spacecraft launched

Moon phase Tuesday 11

1877: James Jeans born
1985: International Cometary Explorer satellite probes Comet Giacobini-Zinner (first comet flyby)
1997: Mars Global Surveyor arrives at Mars

Moon phase Wednesday 12

Venus 10° south of Moon

1959: Luna 2 launched
1966: Gemini XI launched
1970: Luna 16 launched
1991: STS-48 Discovery launched
1992: STS-47 Endeavour launched
1993: STS-51 Discovery launched
2017: Soyuz MS-06 launched carrying ISS Expedition 53/54 crew

Moon phase Thursday 13

Jupiter 4° south of Moon

1977: Second glide test of Space Shuttle Enterprise
1978: Venera 12 launched

Moon phase Friday 14

1966: Gemini XI, docked with Agena booster rocket, reaches 850-mile-high orbit

Moon phase Saturday 15

1965: “Lost in Space” premieres
1968: Zond 5 launched, first circumlunar spaceflight with living creatures (tortoises)
2016: Tiangong-2 space station launched
2017: Cassini mission ends with planned entry into Saturn’s atmosphere

Moon phase Sunday 16

First Qtr Moon 7:15 PM ET

1848: First observation of Hyperion, moon of Saturn
1996: STS-79 Atlantis launched

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