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.
2003 June 25 
Posted on 06/25/2003 3:12:28 AM PDT 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.
2003 June 25
Explanation: This tantalizing view of galaxies scattered near and far is part of the Hubble Space Telescope's contribution to the GOODS - the Great Observatories Origins Deep Survey project. The GOODS' goal is to study galaxy formation and evolution over an unprecedent wide range of cosmic distances, therefore spanning time from the present to the early Universe. Joined by the Chandra X-ray Observatory and soon by the anticipated Space Infrared Telescope Facility along with major ground-based observatories, the project expands greatly on the past Hubble Deep Fields of regions in the northern constellation of Ursa Major and southern constellation Tucana. Across the electromagnetic spectrum, a sample of large nearby galaxies, like the interacting pair at the lower left above, will be compared with distant younger galaxies in a search for clues to the origins of these lighthouses of the cosmos. Preliminary results of the project confirm that the birth rate of stars was higher in the past and that galaxies have indeed been constructed from the "bottom up", growing from mergers and accretion of small infant galaxies to their present day forms.
The Space InfraRed Telescope Facility (SIRTF) is a space-borne, cryogenically-cooled infrared observatory capable of studying objects ranging from our Solar System to the distant reaches of the Universe. SIRTF is the final element in NASA's Great Observatories Program, and an important scientific and technical cornerstone of the new Astronomical Search for Origins Program.
| Launch Date: | August 2003 |
| Launch Vehicle/Site: | Delta 7920H ELV / Cape Canaveral, Florida |
| Estimated Lifetime: | 2.5 years (minimum); 5+ years (goal) |
| Orbit: | Earth-trailing, Heliocentric |
| Wavelength Coverage: | 3 - 180 microns |
| Telescope: | 85 cm diameter (33.5 Inches), f/12 lightweight Beryllium, cooled to less 5.5 K |
| Diffraction Limit: | 6.5 microns |
| Science Capabilities: | Imaging / Photometry, 3-180 microns Spectroscopy, 5-40 microns Spectrophotometry, 50-100 microns |
| Planetary Tracking: | 1 arcsec / sec |
| Cryogen / Volume: | Liquid Helium / 360 liters (95 Gallons) |
| Launch Mass: | 950 kg (2094 lb) [Observatory: 851.5 kg, Cover: 6.0 kg, Helium: 50.4 kg, Nitrogen Propellant: 15.6 kg] |
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