Dawn Arrives at Vesta

While some lament the end of the space shuttle program, NASA is still doing serious science using robots to explore the wonders of our solar system and beyond...

This weekend NASA’s Dawn spacecraft, launched in 2007, will enter orbit around Vesta, our solar system’s second most massive asteroid. Dawn has traveled 1.57 billion kilometers using an electrically powered ion propulsion system (and a gravitational assist from Mars) to visit Vesta. Dawn will map Vesta from orbit until next July when it will move on to Ceres, the largest asteroid in our solar system and an actual dwarf planet. These asteroids are described by some as proto-planets, "baby planets" whose growth was interrupted by Jupiter, the gravity of which slurped up all the spare planet-making ingredients in its neighborhood. Vesta has a diameter of roughly 330 miles (about the distance from Minneapolis, MN, to Grand Forks, ND), is 2.5 times farther from the Sun than is Earth, and exerts only 2% the gravity we feel on Earth.  While the STS is about to be finally grounded, humankind is still exploring Mercury, Mars, the asteroid belt, and Saturn, and has a mission half way to the not-planet Pluto and its moons, and dozens more looking here and there.  We're doing okay (if not always great) as a species committed to discovery.