21 Lutetia

Asteroid 21 Lutetia is a significant celestial body located in the asteroid belt between Mars and Jupiter. Discovered on November 15, 1852, by the French astronomer Hermann Goldschmidt, Lutetia is a large main-belt asteroid with an approximate diameter of about 100 kilometers (62 miles). Named after Lutetia, the ancient Roman name for Paris, this asteroid orbits the Sun at an average distance of around 384 million kilometers (238 million miles), completing one orbit roughly every 3.8 Earth years. One of its significant events was the visit by the European Space Agency's Rosetta spacecraft in 2010. During this encounter, Rosetta made a close flyby of Lutetia, providing detailed images and data that allowed scientists to study its surface features, composition, and structure. The observations revealed a heavily cratered surface, indicating a long history of collisions, and offered insights into the asteroid's composition, suggesting it is likely a primitive body, possibly made of primitive material left over from the formation of the solar system.