Astronomers Largest Tools and Sites

Professional astronomers, today, are operating either from the ground -through the various wavelengths available there- or from space, using dedicated space telescopes

Ground Telescopes Ground Radio Telescopes

Space Telescopes

Ground Telescopes

the Keck I and II telescopes at the summit of the Mauna Kea, Hawai

Most of the ground telescopes the professional astronomers are using today are of the reflecting type. The instruments, on the other hand, are remotely operated. No more nights in the dark and the cold in the prime focus cage of the giant reflectors, as the astronomers now work in a comfortable command room which is located just near their instrument

• the Mauna Kea site. It's on this summit of the Big Island, in Hawaii, USA, that the world's largest astronomical observatory is located. 13 telescopes are working near the summit of the Mauna Kea, at an altitude of 13,796 ft (4,205 m). The observatories, at the summit, are working in the optical, infrared, submillimeter and radio wavelengths. Of them, the famed Keck Observatory features the twin Keck telescopes. Both instruments are eight-story tall as they weigh 300 tons, with a 10-meter multi-celled mirror each. In the near and the mid-infrared, the Keck telescopes are using adaptive optics which compensate for the atmospheric distortions, and interferometery too, which combines the light from the both telescopes. The Keck I and II are operated by the Caltech (the famed 'California Institute of Technology', Calif.). The other institutions and countries operating at the Mauna Kea site are the University of Hawaii, the NASA, Canada, France, the United Kingdom, and Japan. The James Clerk Maxwell Telescope (JCMT) is the largest submillimeter telescope in the world, as the 8.2-meter, optical-infrared Subaru is operated by Japan. The Keck I and II are the world's largest telescopes. a good start about the Mauna Kea observatories is at http://www.ifa.hawaii.edu/mko/maunakea.htm, via the University of Hawaii, Institute for Astronomy
• the European Southern Observatory (ESO). With its two sites, at La Silla and Paranal, in Chile, the European Southern Observatory (ESO) is an intergovernmental European research organization, with 11 countries participating. Its headquarters are in Garching, near Munich, Germany. The Paranal site, with the four 8.2-meter units, which can be operated through interferometry into the Very Large Telescope Interferometer (VLTI), is the main site of the organization. The four telescopes, working individually, are working in the visible and the infrared. They are named, in this case, the Very Large Telescope (VLT). The Paranal site is located 82 miles (130 km) south of Antofagasta, Chile, in the Atacama Desert, on the 8,600-ft (2,600-m) Cerro Paranal summit. The La Silla site is harboring middle-sized instruments mainly, of the order of 2 meters in diameter. It's located at the southern extremity of the Atacama Desert, 100 miles (160 km) North of La Serena, Chile. for more see at the European Southern Observatory
• the Instruments of the National Optical Astronomy Observatory (NOAO). The National Optical Astronomy Observatory (NOAO) is the acting managing institution for the AURA (the 'Association of Universities for Research in Astronomy'), a consortium of 32 universities and educational and other non-profit institutions, operating world-class astronomical observatories. The NOAO is funded by the National Science Fundation (NSF), the US federal agency responsible for the progress of science and the funding source for 20 percent of all federally supported, colleges and universities searches in the United States. The NOAO is headquartered in Tucson, Arizona. The NOAO is responsible for the Kitt Peak National Observatory, this observatory located in the Sonora Desert, on the Kitt Peak Mountain, 55 miles (90 km) southwest of Tucson. It holds more than 20 telescopes, of them the Mayall 4-meter. The Kitt Peak Mountain is home too to the National Solar Observatory (NSO), with the famed McMath-Pierce Solar Telescope (the NSO manages too another facility at the Sacramento Peak). The NOAO, further, is managing the Cerro Tololo Inter-American Observatory, located in northern Chile. A 4-meter telescope, among others, is found there. The NOAO, at last, is the U.S. astronomical community representative to the joint, multinational International Gemini Project. This project comprises two twin 8.1-meter telescopes, one at the Mauna Kea, the other near the Cerro Tololo. Such both locations introduce to studies of the northern and the southern hemispheres sky. The telescopes are integrated with modern networking technologies. Their headquarters are found in Hilo, Hawaii and La Serena, Chile. for more see the NOAO site
• the Lick Observatory is a multi-campus research unit of the University of California. It is located atop the 4,200-ft (1,400-m) Mount Hamilton, which is found in the Diablo Range, east of San Jose, California. Due to an effective counter-light-pollution program, the Lick Observatory, although located near urban centers, is still able to perform an important astronomical work. The Adaptive Optics/Laser Guide Star Program is another aspect of how the Lick Observatory works. This program allows the Shane 3-meter reflector to compensate for the effects of atmospheric turbulences through a deformable mirror. The Lick Observatory is home, too, to the ancient, 36-inch Lick Refractor. for more see at University of California Observatories/Lick Observatory
• the Palomar Observatory, on the 5,600-ft (1,800-m) Palomar Moutain, 100 miles (160 km) southeast of Pasadena, Calif. had its history beginning in 1930 when a new site was searched by George E. Hale, an American astronomer, in the name of the Caltech (the 'California Institute of Technology') for a 200-inch (5-meter) telescope, which was funded by the Rockfeller Foundation. The telescope eventually became operational in 1949, as its name had been changed meanwhile to the 'Hale Telescope'. The 200-inch telescope was the world's largest telescope between 1948 and 1993. This telescope was instrumental to the development of the Big Bang theory. The 200-inch Hale Telescope of the Mount Palomar is still an astronomical workhorse today, which is used at the Palomar observatory along with other famed telescopes, like the 18-inch and 48-inch Schmidt Camera telescopes. for more see at the Palomar Observatory site
• the Big Bear Solar Observatory (BBSO) is managed by the New Jersey Institute of Technology for a univesity consortium. It is located 100 miles East of Pasadena, California, in the middle of Big Bear Lake, at an elevation of 6,700 ft (2,200 m). It's the main location in the world for the observation of the Sun. for more see at the BBSO, Big Bear Solar Observatory

Ground Radio Telescopes

antennas of the VLA, Socorro, New Mexico. picture NRAO

Radio astronomy is the branch of astronomy which works in the radio range as it studies the radio waves emanating from the celestial objects, from the black holes at the center of the galaxies to the Sun or the interstellar gas clouds. Radio astronomy started in the 1930s only. Radio astronomy is working in the wavelengths of about 10 meters (30 MHz) and 1 millimeter (300 GHz). Radio-telescopes, just like their optical counterparts, may work on the principle of interferometry, combining their strength to yield high-resolution virtual receivers. Such radio facilities, on the other hand, may be networked, worlwide, producing higher resolution still

• the National Radio Astronomy Observatory (NRAO) facilities. The NRAO is an institution of the National Science Foundation (NSF), this US federal agency responsible for the scientific research in the USA. The NRAO is operated under coooperative agreement by Associated Universities, Inc., a group of the northeastern universities, founded in 1946. The NRAO is managing 5 major radio astronomy facilities: the Very Large Array (VLA), an ensemble of 27 82-foot (25-m) antenna gathered into a Y-shaped configuration 50 miles West of Socorro, New Mexico. In its widest configuration the Y shape may attain 26 miles (42 km) in length. The Very Long Baseline Array (VLBA), on the other hand, is a worldwide system of 10 82-foot (25-m) radio-telescope antennas, mostly spreaded in the continental USA (with one at the Mauna Kea, Hawaii). Antennas are found, for example,in Kitt Peak, Arizona, Owens Valley, California, or Hancock, New Hampshire. The NRAO, at last, is managing the Green Bank Telescope (GBT), the world's largest fully steerable radio-telescope, located in Green Bank, Pocahontas County, West Virginia. This antenna is 100-meter wide. The Atacama Large Millimeter Array (ALMA) is an international, ESO (European Southern Observatory)-USA-Canada project, which is expected to feature about 64, 39-foot (12-m) antennas located in Llano de Chajnantor, Chile, in the Atacama Desert. It can be configured in different ways, with dimensions ranging from 500 ft (150 m) to 10 miles (16 km). The Expanded Very Large Array (EVLA) Project, at last, is building upon the net of antennas of the VLBA, expecting to add 8 more antennas to the network. for more, see at the National Radio Astronomy Observatory site

Space Telescopes

the Hubble Space Telescope as seen in orbit. picture NASA

NASA currently has three major space telescopes orbiting in space: the Hubble Space Telescope, the Chandra X-Ray Observatory, and the Spitzer Space Telescope. Those space telescopes allow for the observation of the Universe at various wavelengths. Another NASA space observatory was the Compton Gamma Ray Observatory, which was working in the gamma rays. It has already been de-orbited

• the Hubble Space Telescope. Advocated by astrophysicist Lyman Spitzer about 1970, the Hubble Space Telescope began to be built in 1981 in Baltimore, Maryland. The telescope was eventually released into orbit in April 1990 by the Space Shuttle STS-31 mission. After that a grave optical defect was discovered in the telescope's primary mirror, and that COSTAR, a complex packaging of mirror pairs to rectify that was installed in 1993, the Hubble Space Telescope is still able to work. It's working in the visible and the infrared. Three servicing mission by the Space Shuttle, in 1997, 1999, and 2002, provided Hubble with new instruments, replacement parts, and maintenance. The fate of the Hubble Space Telescope is still unclear now as it's aging and that the question of next servicing missions by the Space Shuttle is still pending, mainly due to the accident of Shuttle Columbia in February 2003. The Hubble Space Telescope is a joint ESA (European Space Agency)/NASA project. Hubble is orbiting in a Low Earth Orbit (LEO), at about 375 miles (600 km) above the surface of the Earth. Such an altitude allows the telescope to escape the distorting effects of the Earth's atmosphere as it permits however for servicing missions. Hubble is completing an orbit every 97 minutes. see more at the Hubble's page at NASA
• the Chandra X-Ray Observatory was deployed in space in July 1999, by the Space Shuttle STS-93 mission. It's was the most sophisticated X-ray observatory built to that date. Chandra is working in the X-rays as it studies the high-energy regions of our Universe. It's Chandra which is providing with those now famed pictures of supernovae remnants or of gas clouds in galaxies clusters. The telescope was named the Chandra X-ray Observatory in honor of the late Indian-American Nobel laureate, astrophysicist Subrahmanyan Chandrasekhar. The Chandra X-Ray Observatory is on a highly elliptical orbit. It's getting distant from the Earth up to 86,500 miles (139,000 km) away! see more at the Chandra site
• the Spitzer Space Telescope. The Space Infrared Space Infrared Telescope Facility (SIRTF), is studying the Universe in the infrared. The telescope was renamed the "Spitzer Space Telescope" in honor to Dr. Lyman Spitzer Jr. who worked at Princeton University for 50 years and was the first to propose, in 1946, to put telescopes into orbit. The Spitzer Space Telescope is coming like a complement to the Hubble Space Telescope, which works in the visible light, and the Chandra X-ray Observatory, which works is the X-rays. The Spitzer Space Telescope launched in August 2003. To avoid the warmth of the Earth, it's trailing behind it, on the orbit. The distance to the Earth will lengthen by 0.1 AU a year. The telescope is operated by the JPL for NASA. see more at the Spitzer Space Telescope site
• the Solar and Heliospheric Observatory (SOHO) is not, so to speak, a space telescope. It's better a space mission. Its contribution to the daily study of the solar activity however allows to award it its place on this page. SOHO is a cooperative ESA (European Space Agency)/NASA mission which was launched in December 1995. Soho is orbiting at the Lagrangian point L1, between the Earth and the Sun. It provided from there an uninterrupted series of data about the solar activity as seen in various wavelengths. Such data are of importance as the "solar weather" may affect the satellites in orbit around the Earth. Since June 2003, the aging satellite has had its high gain antenna parked, as the craft is rotated now each half-orbit to keep it Earth-directed. This brings to some "blackout" periods about every 3 months

Some shorter-lived space missions regularly launch to the terrestrial orbit for dedicated missions, like the Galex mission which is studying the galaxies in the ultraviolet, or the Swift craft which is dedicated to the gamma-rays bursts. Such missions are launched by NASA or by other space agencies. for more about such missions, see our page "Missions"