BARBARA KLEIN: NASA launched Dawn from Cape Canaveral in Florida four years ago. The spacecraft had to travel about three billion kilometers to reach Vesta. The spacecraft will move closer and closer to the asteroid until it is eventually within one hundred twenty kilometers of Vesta’s surface.
After Dawn has finished collecting information, it will move on to explore its next target.
MARC RAYMAN: “We will use the tremendous capabilities of this ion propulsion system to climb out of orbit around Vesta, travel for almost another three years through the asteroid belt to dwarf planet Ceres and then go into orbit around Ceres and undertake the same kind of measurements there that we’ll be doing at Vesta. And that will make Dawn the first spacecraft ever to orbit two different Solar System destinations.”
Ceres was once considered the largest asteroid. It was discovered in eighteen oh-one. Now it is defined as a dwarf planet.
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Happy Birthday, Neptune!
MARIO RITTER: This month, Neptune completed one full orbit around the sun since its discovery one hundred sixty-five years ago. The big, blue, icy planet was first discovered in eighteen forty-six.
A Hubble Space Telescope picture of Neptune taken to mark the anniversary of the planet's discovery.
Neptune remains the first, and only, planet found with math. The French mathematician Urbain Le Verrier predicted its existence while studying the unusual orbital movements of the planet Uranus. He believed a more distant planet was affecting Uranus’ motion. He sent his predictions to a German astronomer at the Berlin Observatory.
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