4 Vesta is one of the largest asteroids in the Asteroid Belt, located between the orbits of Mars and Jupiter. Discovered in 1807 by the astronomer Heinrich Wilhelm Olbers, Vesta is classified as a protoplanet due to its size and differentiated structure, which includes a core, mantle, and crust. Vesta has a diameter of about 525 kilometers (326 miles) and is known for its unique surface features, including large craters and a bright, reflective surface. It is also the only asteroid visible to the naked eye from Earth under ideal conditions, making it a fascinating object for both amateur and professional astronomers.