Asteroids!

Today we have Vesta on approach! Ehh... What is Vesta? Well, it is an asteroid! A big chunk of rock in the asteroid belt. Where is this asteroid belt, you may ask?  It is roughly between the orbits of Mars and Jupiter.  But where did they come from?   The answer is... From the same stuff the planets were made of, the primordial solar nebula.   But if that is the case,  why are they not planets?  Excellent question!  The asteroid belt destiny was to become a planet.  All those rocks were supposed to stick together but big Jupiter and Mars continously "tug" on these rocks adding gravitational energy to the mix and preventing the "planetesimal" (another funny word for big chunk of rock in space) to become planets.

So why is this asteroid named Vesta?  Well, I say... why not?  Ok, ok, like the planets, the first asteroids were believed to be planets and so they follow suit and named them after Greek Mythological Gods.  The first asteroid discovered was named Ceres in 1801, then Pallas followed in 1802 and Juno on 1804.   The fourth asteroid discovered in 1807 was named then Vesta by astronomer Heinrich Wilhelm Olbers.  The asteroid is 330 km in diameter and it is big enough to be considered a protoplanet (just shy of a planet).  The video above was provided by NASA's Dawn Spacecraft.

NASA's Dawn Spacecraft Artistic Concept