Euclid (named after the ancient Greek mathematician
Euclid of Alexandria, the "Father of
Geometry"), is a space mission currently under development by the
European Space Agency (ESA). The objective of Euclid is to better understand
dark energy and
dark matter by accurately measuring the
acceleration of the universe. To achieve this, the spacecraft will measure the
redshift of galaxies at varying distances from Earth and investigate the relationship between distance and redshift. Dark energy is generally accepted as contributing to the increased acceleration of the expanding universe, so understanding this relationship will help to refine how
physicists and
astrophysicists understand it. Euclid's mission advances and complements ESA's
Planck mission, and other contemporary space missions.