solar eclipse

solar eclipse
Name	Solar eclipse

solar eclipse A solar eclipse occurs when the Moon passes between the Earth and the Sun, producing a temporary obscuration of the solar disk as seen from specific locations on Earth. Observers within the Moon's shadow experience variations from total obscuration to partial dimming depending on geometry tied to the Moon's orbit, the Earth's curvature, and the relative apparent sizes of the Sun and Moon. Predictions and recordings of eclipses have involved institutions such as the Royal Observatory, Greenwich, the United States Naval Observatory, the Jet Propulsion Laboratory, and projects like the Eclipse Megamovie Project.

Definition and Classification

Astronomical definitions rely on positional geometry established by observatories and agencies including the International Astronomical Union, the NASA, the European Space Agency, and the National Astronomical Observatory of Japan. Classification schemes separate events into categories used by the Minor Planet Center and the American Astronomical Society for catalogs and predictions. Historical catalogs published by astronomers at the Royal Society and the Smithsonian Institution have standardized terminology employed by planetaria such as the Griffith Observatory and the Hayden Planetarium.

Causes and Mechanics

The cause is orbital alignment: the Moon's shadow cast on the Earth's surface during a syzygy when the Moon is in conjunction with the Sun as seen from Earth. Orbital elements defined by the Jet Propulsion Laboratory and computed using ephemerides from the International Celestial Reference System and the VSOP planetary theory determine contact times, path of totality, and magnitude. Mechanics incorporate the Moon's elliptical orbit with perigee and apogee parameters studied at the CERN-linked research groups and modeled by software maintained by the Harvard-Smithsonian Center for Astrophysics and the Max Planck Institute for Solar System Research.

Types of Solar Eclipses

Types recognized by the International Astronomical Union and summarized in atlases from the Royal Astronomical Society include total, annular, partial, and hybrid eclipses. Total eclipses occur when the Moon's umbra reaches the Earth's surface, a phenomenon documented by expeditions led by figures associated with the Royal Society and observers from the Smithsonian Astrophysical Observatory. Annular eclipses happen when the Moon's apparent diameter is smaller than the Sun's, described in reports by the National Geographic Society and field teams from the Lick Observatory. Partial eclipses are common in catalogs maintained by the International Astronomical Union and the American Meteorological Society for atmospheric impact assessments. Hybrid eclipses alternate between total and annular along the path; they have been focal events for campaigns by the European Southern Observatory and the South African Astronomical Observatory.

Observation and Safety

Observation practices follow safety standards issued by the World Health Organization and directives referenced by the American Astronomical Society and the British Astronomical Association. Recommended equipment—solar filters, mylar viewers, and projection methods—are specified by institutions such as the Royal Observatory, Greenwich and organizations like the Astronomical Society of the Pacific. Imaging and timing campaigns often involve collaborations among the Jet Propulsion Laboratory, the Smithsonian Institution, the National Science Foundation, and university groups at Caltech and the Massachusetts Institute of Technology. Medical concerns addressed by the American Academy of Ophthalmology and public advisories from the Centers for Disease Control and Prevention accompany major eclipse events.

Historical and Cultural Significance

Eclipses have influenced narratives across civilizations documented by the British Museum, the Vatican Library, and the Library of Congress. Ancient records from the Babylonian Empire, the Han dynasty, and the Maya civilization feature eclipse observations used by scholars at the University of Cambridge and the University of Oxford to refine chronologies. In modern history, expeditions by teams affiliated with the Royal Society and the Smithsonian Institution during the 19th and 20th centuries produced measurements cited in works by researchers at the National Academy of Sciences and in publications of the Royal Astronomical Society. Cultural responses have involved ritual, prophecy, and artistic representation in collections at the Metropolitan Museum of Art and the Hermitage Museum.

Scientific Research and Applications

Scientific uses include tests of gravitational theories and solar physics investigations conducted by groups at the Royal Observatory, Greenwich, the Mount Wilson Observatory, the Palomar Observatory, and space missions from the European Space Agency and the NASA Goddard Space Flight Center. Totality permits coronal studies that guided early work by scientists associated with the Royal Society and later instrumentation developed at the Max Planck Institute for Solar System Research. Modern research leverages eclipse observations for atmospheric science pursued by teams at the National Oceanic and Atmospheric Administration, climate studies at the Intergovernmental Panel on Climate Change, and calibration of solar irradiance models maintained by the National Renewable Energy Laboratory and the Laboratory for Atmospheric and Space Physics.

Category:Astronomical events