Claudia is a small crater that formerly defined the

prime meridian A prime meridian is an arbitrarily chosen meridian (geography), meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. On a spheroid, a prime meridian and its anti-meridian (the 180th meridian ...

of the asteroid

4 Vesta Vesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta (mytho ...

. The convention of defining Vesta's prime meridian from Claudia is informally referred to as the ''Claudia coordinate system''. The crater was named after the Roman Vestal Virgin Claudia by the ''Dawn'' mission team; the name Claudia was officially approved by the IAU on 30 September 2011. Claudia was chosen because it is small, sharply defined, easy to find, and near the equator. The prime meridian runs 4° to the west. This results in a more logical set of mapping quadrants than the IAU coordinate system, which drifts over time due to an error in calculating the position of the pole, and is based on the 200 km Olbers Regio, which is so poorly defined that it is not even visible to the ''Dawn'' spacecraft. The Claudia coordinate system was the coordinate system used by the ''

Dawn Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the diffuse sky radiation, appearance of indirect sunlight being Rayleigh scattering, scattered in Earth's atmosphere, when the centre of the Sun's disc ha ...

'' mission team,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

, and the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

's ''Gazetteer of Planetary Nomenclature'' (GPN). However, the Claudia coordinate system has since been superseded by the ''Claudia Douple-Prime system'' (also called the Planetary Data coordinate system), where Claudia is defined at the 146°E. The Claudia Double-Prime system is therefore offset 150° east from the Claudia coordinate system .

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References

Impact craters on asteroids Surface features of 4 Vesta {{asteroid-stub