Getting between the planets isn’t easy if you want to stop at multiple destinations on one tank of propellant. Currently the only probe able to do so – unless they do some orbital gymnastics with Cassini – is NASA’s DAWN. Currently DAWN is seemingly within spitting distance (~0.48 AU) of Vesta, its first port-of-call, but both are going too fast to stop. That maneuver is approximately 439 days away according to the count-down clock.

Vesta is an interesting little world – surprisingly an asteroid covered in lava/basalt. Interestingly we already have samples of it available for study, in the form of the HED meteorites, which are the many scattered remains of an immense collision that ripped off a huge chunk of Vestan crust ~1 Gya.

Question: Why did Vesta melt and spew lava, but so many of its asteroidal siblings didn’t too?