Comet Halley's Nucleus: An Orbiting Iceberg

What does a comet nucleus look like? Formed from the primordial stuff of the Solar System, comet nuclei were thought to resemble very dirty icebergs. But ground-based telescopes revealed only the surrounding cloud of gas and dust of active comets nearing the Sun, clearly resolving only the comet's coma, and the characteristic cometary tails. In 1986, however, the European spacecraft Giotto

A Force from Empty Space: The Casimir Effect

This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is known as the Casimir Effect, named for its discoverer, who, 50 years ago, was trying to understand why fluids like mayonnaise move so slowly. Today

Blue Moon Eclipse

The International Year of Astronomy 2009 ended with a Blue Moon and a partial lunar eclipse, as the second Full Moon of December grazed the Earth's shadow on December 31st. The New Year's Eve Blue Moon eclipse was visible throughout Europe, Asia, Africa and parts of Alaska, captured in this two exposure composite in cloudy skies over Saint Bonnet de Mure, France. Playing across the Moon's

Not a Blue Moon

This bright Full Moon was captured on December 2nd, shining above a church overlooking the River Po, in Turin, Italy. It was the first Full Moon in December. Shining on celebrations of New Year's Eve, last night's Full Moon was the second Full Moon of December and so fits the modern definition of a Blue Moon - the second Full Moon in a month. Because the lunar cycle, Full Moon to Full Moon,

Astronomy Picture of the Day Archive

Astronomy Picture of the Day ArchivesAstronomy Picture of the Day Archive 2009Astronomy Picture of the Day Archive 2010

Astronomy Picture of the Day 2009 Archive

Astronomy Picture of the Day Archives


Astronomy Picture of the Day 2009 Archives


Visit Here For Astronomy Picture of the Day Archive 2010 
Visit Here For Astronomy Picture of the Day Archive 2011 


2009 December 31: Dust and the Helix Nebula
2009 December 30: Spitzer's M101
2009 December 29: Rigel and the Witch Head Nebula
2009 December 28: Barred Spiral Galaxy NGC 6217
2009

Astronomy Picture Of The Day 2010 Archive

Astronomy Picture of the Day Archive
Astronomy Picture of the Day 2010 Archives


Click Here for Astronomy Picture of the Day Archive 2009
Click Here for Astronomy Picture of the Day Archive 2011




2010 December 31: Analemma 2010
2010 December 30: Still Life with NGC 2170
2010 December 29: Eclipse at Moonset
2010 December 28: Skylights Over Libya
2010 December 27: One Million