By Casey Frye, CCNN Writer
Last year, the Rosetta carrier ship from the European Space Agency (ESA) became the first comet-orbiting spacecraft ever, flying side by side 34,000 miles per hour with a comet called 67P. Then, the Rosetta released its Philae lander, which successfully survived a 7-hour descent to actually land on the comet! Now, it’s finally waking up from a 7-month nap, sending back groundbreaking data to scientists.
So, what exactly is a comet? Well, the asteroids that hurtle through space are usually made of metals and minerals, while comets are like enormous dirty snowballs filled with ice, rocky materials, dust, and frozen gases. The most mysterious of these two travelers is definitely the comet, but that may not be the case for long!
Over 300 million miles from Earth, Rosetta shares a common orbit around the Sun with 67P. When scientists deployed the Philae lander (which hitched a ride aboard Rosetta), they aimed for a sunny region called Agilkia on the comet’s “head”. Unfortunately, Philae’s battery ran out soon after landing, because it ended up in a place too shady to get sunlight for solar power. Now, it’s back online, and scientists are eagerly awaiting a treasure trove of data.
The 6.5 year orbit of the Rosetta spacecraft will eventually see it go way past Jupiter, and when the comet gets near the Sun, scientists are hoping to get some up close data on the icy melting process that occurs. Once the fiery temperatures hit the comet’s core, it will create an ultra-bright halo effect and the huge dusty tail that we often associate with these starry tourists.
The 2.5-mile-wide surface of the comet has cliffs, plains, and big cracks in it. Like all comets, it’s also filled with leftover parts from the birth of our Solar System 4.6 billion years ago, that didn’t end up being used in planet formation. The Rosetta mission is going to examine these ancient materials to unlock the icy secrets of cosmic history.
Images courtesy of European Space Agency.