It’d be hard to invent a more Star Wars-esque spacecraft than Dawn. It’s 65 feet from tip to tip. It’s exploring the asteroid belt. And it’s got an ion drive, for Pete’s sake.
But Dawn also has a serious job to do. Launched in 2007, it’s been investigating Ceres and Vesta, two mysterious protoplanets in the asteroid belt between Mars and Jupiter. These are smallish, truly ancient bodies, remnants of the early solar system (protoplanets being bodies that formed early on, some of which turned into actual planets like the one you’re sitting on) with plenty of secrets to tell―secrets that Dawn has been handedly unraveling.
Why pick these objects, of all the objects in the solar system? Because figuring out what makes them tick will give scientists insights into how asteroids and protoplanets and actual planets form. And what they’re finding is exhilarating. They’ve explored a massive impact on Vesta, which flung heaps of material into space. And on Ceres, they eyeballed a cryovolcano that spews brine instead of lava. Water, of course, is a prime ingredient for life.
Dawn only got where it is because of its ion drive, which unlike a conventional engine, actually sends electricity through xenon fuel, breaking out ions. These propel the spacecraft, but only very weakly. No matter, though―Dawn has been accelerating for five and a half years in the vacuum of space. That’s allowed the spacecraft to change its velocity by 25,000 miles per hour.
So ten years after it left the comfort of Earth, we’re checking in on Dawn. Peep the video above to see where Dawn’s been, where it’s going, and the tantalizing discoveries it’s made along the way.