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What's Up in 2013 - at a glance

All year long, astronomers have been writing about Comet ISON: will it sizzle or will it fizzle? Both! Here’s my What’s Up video, with December status (written in mid November, but luckily, the comet didn’t completely fizzle)

ISON in December 2013

Comet ISON first spotted by amateur astronomer Bruce Gary and has been imaged by many [...]

The Crescent Moon

The moon's summer and winter path, courtesy NASA's Starchild website

The winter’s moon – a smiling crescent just after sunset Feb 5, 2011 (click to see moon upper center)

Closeup of winter crescent moon

The summer's "backwards C" crescent moon at sunset, late June 2007 (click to see moon in lower right)

Closeup [...]

Chasing Galileo – Jupiter and the four Galilean satellites

Galileo’s drawing

my drawing

my sketch of Jupiter’s rotation

Galileo published his observations in Sidereus Nuncius in March 1610: “On the 7th day of January in the present year, 1610, in the first hour of the following night, when I was viewing the constellations of the heavons through a telescope, the planet Jupiter [...]