Full-sky Astrometric Mapping Explorer
Encyclopedia
Full-sky Astrometric Mapping Explorer (or FAME) was a proposed astrometric
satellite
designed to determine with unprecedented accuracy the positions, distances, and motions of 40 million star
s within our galactic neighborhood (distances by stellar parallax
possible). This database was to allow astronomers to accurately determine the distance to all of the stars on this side of the Milky Way galaxy, detect large planets and planetary systems around stars within 1,000 light years of the Sun, and measure the amount of dark matter in the galaxy from its influence on stellar motions. It was to be a collaborative effort between the United States Naval Observatory
(USNO) and several other institutions. FAME would have measured stellar positions to less than 50 microarcseconds. The NASA
MIDEX mission was scheduled for launch in 2004. In January 2002, however, NASA abruptly cancelled this mission, mainly due to concerns about its price tag which grew from $160 million to $220 million.
This would have been an improvement over the High Precision Parallax Collecting Satellite (Hipparcos) which operated 1989-1993 and produced various star catalogs. Astrometric parallax measurements form part of the cosmic distance ladder
, and can also be measured by other Space telescopes such as Hubble
(HST) or ground-based telescopes to varying degrees of precision.
Compared to the FAME accuracy of 50 microarcseconds, the Gaia mission is planning 10 microarcseconds accuracy, for mapping stellar parallax
up to a distance of tens of thousands of light-years from Earth.
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...
satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
designed to determine with unprecedented accuracy the positions, distances, and motions of 40 million star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s within our galactic neighborhood (distances by stellar parallax
Stellar parallax
Stellar parallax is the effect of parallax on distant stars in astronomy. It is parallax on an interstellar scale, and it can be used to determine the distance of Earth to another star directly with accurate astrometry...
possible). This database was to allow astronomers to accurately determine the distance to all of the stars on this side of the Milky Way galaxy, detect large planets and planetary systems around stars within 1,000 light years of the Sun, and measure the amount of dark matter in the galaxy from its influence on stellar motions. It was to be a collaborative effort between the United States Naval Observatory
United States Naval Observatory
The United States Naval Observatory is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation, and Timing for the U.S. Navy and the U.S. Department of Defense...
(USNO) and several other institutions. FAME would have measured stellar positions to less than 50 microarcseconds. 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...
MIDEX mission was scheduled for launch in 2004. In January 2002, however, NASA abruptly cancelled this mission, mainly due to concerns about its price tag which grew from $160 million to $220 million.
This would have been an improvement over the High Precision Parallax Collecting Satellite (Hipparcos) which operated 1989-1993 and produced various star catalogs. Astrometric parallax measurements form part of the cosmic distance ladder
Cosmic distance ladder
The cosmic distance ladder is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are "close enough" to Earth...
, and can also be measured by other Space telescopes such as Hubble
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
(HST) or ground-based telescopes to varying degrees of precision.
Compared to the FAME accuracy of 50 microarcseconds, the Gaia mission is planning 10 microarcseconds accuracy, for mapping stellar parallax
Stellar parallax
Stellar parallax is the effect of parallax on distant stars in astronomy. It is parallax on an interstellar scale, and it can be used to determine the distance of Earth to another star directly with accurate astrometry...
up to a distance of tens of thousands of light-years from Earth.