International Halley Watch
Encyclopedia
Halley's Comet, named after English astronomer Edmund Halley who first demonstrated its periodicity, returns to the vicinity of the Sun and Earth approximately every 76 years. Since comet
s are believed to be the most primordial objects in the solar system, their study is of great importance to planetary science. At the time of the 1986 return (technically, “apparition”) of the comet, astronomical telescopes and related instrumentation were vastly more sensitive than for any previous apparition. Consequently, the International Halley Watch (IHW) was organized to stimulate, standardize, collect, and archive observations of the comet.
The initial plans were formulated by scientists at the NASA
Jet Propulsion Laboratory
in California, where a Lead Center for western hemisphere observations was established with support from NASA
; a corresponding Center for eastern hemisphere observations was funded by the Federal Republic of Germany
at the Dr.-Remeis-Sternwarte (Observatory) in Bamberg
. An international Steering Group was established, and a set of Discipline Specialists was chosen to organize observing networks, coordinate their activity, and ultimately to collect and archive their data. This effort was endorsed by the International Astronomical Union
in 1982, and cometary scientists were chosen as Discipline Specialists in the areas of Astrometry
, Infrared
Studies, Large Scale Phenomena, Near-Nucleus Studies, Photometry
and Polarimetry
, Radio Studies, Spectroscopy
and Spectrophotometry
, Meteor Studies, and Amateur Observations. The IHW also coordinated with the space missions to the comet, Giotto by the European Space Agency
and Vega by the Soviet Union
and collaborating countries. The collected data were subsequently published as a digital archive on CD-ROM
s.
References
1. Newburn, R. L. Jr. (1983). “The International Halley Watch”. Cometary Exploration, Vol. III. T. I. Gombosi (ed.). Budapest: Central Research Institute for Physics, Hungarian Academy of Sciences,pp. 19-32. ISBN 963 372 110 5
2. Sekanina, Z.; Fry, L. (1991). The Comet Halley Archive --- Summary Volume. Pasadena, USA: NASA/JPL 400-450, 8/91 (JPL D-400-450)
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s are believed to be the most primordial objects in the solar system, their study is of great importance to planetary science. At the time of the 1986 return (technically, “apparition”) of the comet, astronomical telescopes and related instrumentation were vastly more sensitive than for any previous apparition. Consequently, the International Halley Watch (IHW) was organized to stimulate, standardize, collect, and archive observations of the comet.
The initial plans were formulated by scientists at the NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
in California, where a Lead Center for western hemisphere observations was established with support from NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
; a corresponding Center for eastern hemisphere observations was funded by the Federal Republic of Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
at the Dr.-Remeis-Sternwarte (Observatory) in Bamberg
Bamberg
Bamberg is a city in Bavaria, Germany. It is located in Upper Franconia on the river Regnitz, close to its confluence with the river Main. Bamberg is one of the few cities in Germany that was not destroyed by World War II bombings because of a nearby Artillery Factory that prevented planes from...
. An international Steering Group was established, and a set of Discipline Specialists was chosen to organize observing networks, coordinate their activity, and ultimately to collect and archive their data. This effort was endorsed by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
in 1982, and cometary scientists were chosen as Discipline Specialists in the areas of Astrometry
Astrometry
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. The information obtained by astrometric measurements provides information on the kinematics and physical origin of our Solar System and our Galaxy, the Milky...
, Infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
Studies, Large Scale Phenomena, Near-Nucleus Studies, Photometry
Photometry
Photometry can refer to:* Photometry , the science of measurement of visible light in terms of its perceived brightness to human vision...
and Polarimetry
Polarimetry
Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves...
, Radio Studies, Spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
and Spectrophotometry
Spectrophotometry
In chemistry, spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength...
, Meteor Studies, and Amateur Observations. The IHW also coordinated with the space missions to the comet, Giotto by the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
and Vega by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
and collaborating countries. The collected data were subsequently published as a digital archive on CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....
s.
References
1. Newburn, R. L. Jr. (1983). “The International Halley Watch”. Cometary Exploration, Vol. III. T. I. Gombosi (ed.). Budapest: Central Research Institute for Physics, Hungarian Academy of Sciences,pp. 19-32. ISBN 963 372 110 5
2. Sekanina, Z.; Fry, L. (1991). The Comet Halley Archive --- Summary Volume. Pasadena, USA: NASA/JPL 400-450, 8/91 (JPL D-400-450)
