Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2004 March 14 
Posted on 03/14/2004 3:18:04 AM PST by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2004 March 14
Explanation: Comet Hale-Bopp became much brighter than any surrounding stars. It was seen even over bright city lights. Out away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy. Comet Hale-Bopp's blue ion tail was created when fast moving particles from the solar wind struck expelled ions from the comet's nucleus. The white dust tail is composed of larger particles of dust and ice expelled by the nucleus that orbit behind the comet. Observations showed that Comet Hale-Bopp's nucleus spins about once every 12 hours.
I have made a screen capture of the view on May 10th at 9:30 PM daylight time -- remember, comet brightness varies from the estimates quite often.
Go to THIS PAGE and click on the link "Get Original Uploaded Photo" for the full-sized version.
Telescope on high mountain plateau in Chile studied
CORNELL UNIVERSITY NEWS RELEASE
Posted: March 14, 2004
Cornell University and the California Institute of Technology (Caltech) have signed an agreement committing the two institutions to collaborate on the planning for a 25-meter infrared telescope high in the Atacama Desert of northern Chile.
The universities will focus on the first phase of telescope development, says Riccardo Giovanelli, professor of astronomy at Cornell and project director. During the $2 million study phase, Cornell and Caltech researchers will outline the technical and financial resources required to construct the new telescope. Fred Young, an active Cornell alumnus and retired businessman from Racine, Wisc., will fund most of Cornell's share of the study.
 The summit of Cerro Negro in Chile's Atacama Desert is one possible site for the proposed Cornell-Caltech 25-meter infrared telescope. Credit: Ricardo Giovanelli/Cornell University |
The Atacama telescope will be sensitive to light with wavelengths longer than 200 microns, or 0.2 millimeters. These wavelengths (called far-infrared or sub-millimeter) are too long to be perceived by the human eye, but are shorter than the waves that transmit radio and television signals.
Because these waves are absorbed by water vapor in the Earth's atmosphere, they are difficult to detect from the ground. The high Atacama Desert will position the telescope above most of the water vapor in the atmosphere, making the site one of the best on Earth for far-infrared astronomy.
The new telescope will be "by far the most sensitive sub-millimeter telescope in the world," says Cornell astronomy professor Gordon Stacey, who studies infrared astronomy and instrumentation and has been a major advocate for the project. Because the telescope will be so sensitive -- 30 times more sensitive than current sub-millimeter telescopes -- it will be able to probe star formation during the epoch of galaxy formation, the time in the universe's history at which galaxies first appeared, says Stacey.
Cornell and Caltech researchers also will use the new telescope to study the origin of the large-scale structure of the universe, a filamentary web that Giovanelli describes as a "bowl of spaghetti." Also on the telescope's agenda are circumstellar disks, the rotating pancakes of dust and gas in which planets form. These planetary nurseries are shrouded from optical telescopes by light-absorbing dust, but they emit an infrared glow that could reveal hidden planets.
Giovanelli notes that the telescope will take advantage of the "coming of age" of new sub-millimeter detector technology. Called large format bolometer arrays, these detectors will sensitively measure radiation collected by the telescope over tens of thousands of pixels. Current detectors have only a few hundred pixels and, just as with digital cameras or computer monitors, more pixels create sharper images.
A steering committee, headed by Giovanelli and staffed by four members from both participating universities will direct the project. The study phase is expected to be complete in two years or less, followed by engineering development and construction.
"Caltech is just a wonderful partner, with their long history in sub-millimeter astronomy," says Stacey. Though the agreement does not formally commit Cornell and Caltech to collaboration beyond the study phase, Giovanelli notes that it spells out the universities' intentions to work together to bring the project to completion.
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[number zero of four ;')]
Hale-Bopp Comet Near Earth 4,200 Years Ago, Four Times Larger Than Halley's Comet
Aired March 17, 1997 - 7:31 a.m. ET
http://www.cnn.com/TECH/9703/hale.bopp/stories/ee.02.html
MARTIN SAVIDGE, CNN ANCHOR: You, in your article, one of the things you chart is the history that was taking place the last time that Hale-Bopp came by, and that was estimated to be when?
DAVID KAPLAN, "NEWSWEEK": About 4,200 years ago. And a lot of astronomers get a kick out of seeing this for the reasons you and I might. It's just cool to look at, but for a lot of folks, there's a romance to looking at something no human eyes have seen for 4,200 years. 4,200 years ago the Roman and Greek Empires were but a thing of the future.
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