January 14, 2013 - Simon Says

Simon Says In 1610, when Galileo first observed the four largest moons of Jupiter, he announced their discovery in his book Sidereus Nuncius (The Starry Messenger). In that book, he referred to them as the “Medician Stars” in honor of the family of Cosimo de’ Medici, the Grand Duke of Tuscany. About four years later, Simon Marius, a German astronomer born 440 years ago this week, suggested naming them after lovers of Zeus (the Greek equivalent of Jupiter). Since this was more than three centuries before the International Astronomical Union became the official arbiter of planet and satellite nomenclature, popular consensus carried much weight in these matters and Marius’s names stuck. Today we know these moons individually as (clockwise from top left) Io, Callisto, Europa, and Ganymede.

Image credit: NASA / JPL / DLR

Weekly Calendar

January 14-20, 2013

Holidays - Sky Events - Space History

Moon phase Monday 14

Neptune 6° south of Moon

1975: Earth Resources Technology Satellite is renamed Landsat
2005: Huygens probe lands on Titan
2008: MESSENGER spacecraft makes its first flyby of Mercury

Moon phase Tuesday 15

1973: Luna 21 lander and Lunokhod 2 rover land on Moon
1976: Helios 2 launched
2006: Stardust spacecraft returns samples of comet dust

Moon phase Wednesday 16

1969: First docking of two human spacecraft (Soyuz 5 and Soyuz 4)
2003: STS-107 Columbia launched

Moon phase Thursday 17

Uranus 5° south of Moon

1985: 1,037th and final Aerobee sounding rocket launched

Moon phase Friday 18

Mercury in superior conjunction
First Quarter Moon 6:45 PM ET

2002: Gemini South Observatory dedicated

Moon phase Saturday 19

1747: Johann Bode born
1851: Jacobus Kapteyn born
1965: Gemini II launched
2006: New Horizons launched

Moon phase Sunday 20

1573: Simon Marius born
1930: Edwin “Buzz” Aldrin born
1966: Apollo A-004 launched, first flight test of CSM hardware
1978: Progress 1 launched

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