Hubble Space Telescope Advent Calendar 2008

18Part of the famous "Pillars of Creation" formation in the Eagle Nebula, this eerie, dark structure, resembling an imaginary sea serpent's head, is a column of cool molecular hydrogen gas (two atoms of hydrogen in each molecule) and dust that is an incubator for new stars. The stars are embedded inside finger-like protrusions extending from the top of the nebula. Each 'fingertip' is somewhat larger than our own solar system. The Eagle Nebula is 7,000 light-years distant from Earth. (Jeff Hester and Paul Scowen - ASU, and NASA/ESA) More (see this on Google Sky)

19Tightly wound, almost concentric, arms of dark dust encircle the bright nucleus of the otherwise nondescript galaxy, NGC 2787, in this image created by the Hubble Heritage team. Astronomer Marcella Carollo (Swiss Federal Institute of Technology, Zurich) and collaborators used Hubble's Wide Field Planetary Camera 2 to collect the data in January 1999. (NASA/ESA and The Hubble Heritage Team) More (see this on Google Sky)

20This object, nicknamed Gomez's Hamburger, is a sun-like star about 6,500 light-years away that is nearing the end of its life. The "hamburger buns" are light reflecting off dust and the "patty" is actually the shadow of a thick disk around the central star, which is seen edge-on from Earth. The star itself, with a surface temperature of approximately 18,000 degrees Fahrenheit (10,000 degrees Celsius), is hidden within this disk. However, light from the star does emerge in the directions perpendicular to the disk and illuminates dust above and below it. (NASA and The Hubble Heritage Team - STScI/AURA) More (see this on Google Sky)

21Looking across 26,000 light-years of space toward the center of our Galaxy, Hubble captured this dense view of over 150,000 stars in February of 2004 while monitoring for any dips in brightness, or transits of orbiting planets. 16 candidate stars were found for closer scrutiny. (NASA, ESA, K. Sahu - STScI and the SWEEPS science team) More (see this on Google Sky)

22Seen here is a very thin section of a supernova remnant caused by a stellar explosion that occurred more than 1,000 years ago. On or around May 1, 1006 A.D., observers around the world witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. The supernova was probably the brightest star ever seen by humans, and surpassed Venus as the brightest object in the night time sky, only to be surpassed by the moon. It was visible even during the day for weeks, and remained visible to the naked eye for at least two and a half years before fading away. Today we know that the shockwave of SN 1006 has a diameter of nearly 60 light-years, and it is still expanding at roughly 6 million miles per hour. (NASA, ESA, and the Hubble Heritage Team - STScI/AURA) More

23The Cat's Eye Nebula (NGC 6543), about 3,300 light-years distant, shows a bull's eye pattern of eleven or even more concentric rings, or shells, around the its center. Each "ring" is actually the edge of a spherical bubble seen projected onto the sky - that's why it appears bright along its outer edge. Observations suggest the star ejected its mass in a series of pulses at 1,500-year intervals. These convulsions created dust shells, each of which contain as much mass as all of the planets in our solar system combined (still only one percent of the Sun's mass). The view from Hubble is like seeing an onion cut in half, where each skin layer is discernible. (NASA, ESA, HEIC, and The Hubble Heritage Team - STScI/AURA) More (see this on Google Sky)

24ESO 593-8 is an impressive pair of interacting galaxies with a feather-like galaxy crossing a companion galaxy. The two components will probably merge to form a single galaxy in the future. The pair is adorned with a number of bright blue star clusters. ESO 593-8 is located in the constellation of Sagittarius, the Archer, some 650 million light-years away from Earth. (NASA, ESA, the Hubble Heritage -STScI/AURA, ESA/Hubble Collaboration, and A. Evans, University of Virginia, Charlottesville/NRAO/Stony Brook University) More

25This image is called the Hubble Ultra Deep Field, and it is by far my favorite Hubble image. Starting in late 2003, astronomers pointed Hubble at a tiny, relatively empty part of our sky (only a few stars from the Milky Way visible), and created an exposure nearly 12 days long over a four-month period. The result is this amazing image, looking back through time at thousands of galaxies that range from 1 to 13 billion light-years away from Earth. Some 10,000 galaxies were observed in this tiny patch of sky (a tenth the size of the full moon) - each galaxy a home to billions of stars. Go outside tonight, take a ball-point pen with you, and hold it up in front of the night sky at arm's length. The tip of your pen is about 1 millimeter wide, and at arm's length, it would cover the 10,000 galaxies seen in the Ultra Deep Field image. That's how unbelievably massive the visible universe is. By way of comparison, to really put us Earthlings in our place in the Grand Scheme, please have a look at another famous image, the Pale Blue Dot - a photograph taken of the Earth (the tiny pale speck, top center) by Voyager 1 in 1990 from 4 billion miles away (about 6 light-hours). I will finish with the words of astronomer Carl Sagan about this Pale Blue Dot: "That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar", every "supreme leader", every saint and sinner in the history of our species lived there - on a mote of dust suspended in a sunbeam." (NASA/ESA/S. Beckwith - STScI, and The HUDF Team) -- Best wishes to all, and a Happy New Year - Alan. More (see this on Google Sky)