Short answers, pulled from the story.
4 Vesta was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on the 29th of March 1807 in the constellation Virgo. Olbers had been searching for fragments of a hypothetical destroyed planet since 1802, following the discovery of both Ceres and Pallas.
4 Vesta has a mean diameter of 525 km and a surface area roughly comparable to the land area of Pakistan, Venezuela, Tanzania, or Nigeria - slightly under 900,000 square km. It constitutes an estimated 9% of the total mass of the asteroid belt.
Olbers gave the naming honor to the mathematician Carl Friedrich Gauss, who computed Vesta's orbit in just ten hours. Gauss chose Vesta, the Roman virgin goddess of home and hearth. Gauss also designed the asteroid's symbol, depicting an altar with sacred fire.
NASA's Dawn spacecraft entered orbit around 4 Vesta on the 16th of July 2011, becoming the first space mission to visit Vesta. It mapped the surface from multiple altitudes and left orbit on the 4th of September 2012 to travel onward to Ceres.
Howardite-eucrite-diogenite (HED) meteorites are a group of over 1,200 meteorites thought to be fragments of 4 Vesta ejected by ancient collisions. It is estimated that 1 out of every 16 meteorites found on Earth originated from Vesta, making it one of only eight Solar System bodies from which physical samples are available.
Rheasilvia is a massive impact basin approximately 500 km wide near Vesta's south pole, named after the mythical mother of Romulus and Remus. Its central peak rises 23 km above the crater floor, placing it among the tallest mountains in the Solar System. Crater density measurements place the impact at approximately 1 billion years ago.