By Jane Houston Jones
Each month in 2009 the What's Up podcast series explored the first observation of many celestial objects. This theme honors the 2009 IYA (International Year of Astronomy) theme -- 400 years of telescopic observations. Here is a brief recap of the podcast series. The animations in each podcast show and explain these first observations, telling a great story spanning from the present back to prehistoric times!
January 2009 - Four hundred years ago, Galileo first observed the phases of Venus through a telescope. The prevailing belief was that the sun and planets revolved around the Earth. The phases looked similar to what he saw on Earth's Moon each month.
February 2009 - Galileo's famous observations of the moon from 1609 were the first to be published and publicized in 1610.
March 2009 - When Galileo aimed his telescopes at Saturn in 1610 he wasn't sure what he was seeing. He thought the rings were "handles" or large moons on either side of the planet. A few years later in 1612, he was astounded that the "handles" he previously observed had disappeared! And in 1616, the handles were back, but they looked different. This time he saw two half-circles on either side of the round globe of Saturn.
April 2009 - In 1845, Ireland's Third Earl of Ross, William Parsons, used his huge telescope at Birr Castle in the center of Ireland to observe and sketch the spiral structure of the Whirlpool Galaxy.
May 2009 - Galileo and Englishman Thomas Harriott both observed the sun and sunspots in 1610, but they weren't the first. Chinese and Korean astronomers wrote about sunspots almost three thousand years ago. John of Worcester, who was an English monk, made the earliest existing drawing of sunspots in 1128.
June 2009 - It's called M-13 because this object is the 13th of Charles Messier's 1764 catalog of celestial objects. But he wasn't the discoverer of this cluster! M-13 was discovered half a century earlier by Edmund Halley.
July 2009 - The Milky Way - Ptolemy had identified the six brightest stars in the Pleiades, but Galileo saw 36 stars through his telescope. Through the next two centuries, astronomers used bigger and bigger telescopes to study and map the Milky Way galaxy.
August 2009 - Have you ever wondered what makes these cosmic fireworks? Meteor showers are just the debris of a passing comet or sometimes the debris from a fragmented asteroid.
September 2009 - Jupiter also has four large satellites, three of which are larger than our own moon. These four moons were discovered by Galileo 400 years ago. You can see them yourself with a small telescope or even binoculars, and watch them move around the planet just as Galileo did!
October 2009 - Astronomers have observed the Andromeda galaxy for over a thousand years. Persian astronomer Al-Sufi was the first to record and sketch his observations of what he called "the little cloud". In 964 he published this observation and many others in his "Book of Fixed Stars". Simon Marius first viewed the galaxy through a telescope in 1612.
November 2009 - In 1758, Charles Messier was scanning the skies for comet Halley. He noticed a whitish light, shaped like the flame of a candle in the constellation Taurus. M1, the Crab nebula became the first entry in his catalogue of 110 comet-like objects. 700 years earlier, a "guest star" was visible in the summer sky of 1054. Ancient astronomers in both the old and new worlds documented a new bright star in the daytime sky. It was a supernova in the constellation Taurus and was visible with the unaided eye for nearly two years.
December 2009 - This month's target is in one of the most-recognizable constellations: Orion and features The Orion Nebula - this final podcast of 2009 takes the listener/viewer from Galileo's sketch of the Trapezium stars 400 years ago, to Christian Huygens' first detailed sketch of the nebula itself and on to studies by the Hubble Telescope.