(CNN) - A European space probe called the Rosetta has made history --becoming the first spacecraft to orbit a comet.
Previous missions have performed comet fly-bys but Rosetta is different. This probe will follow the comet for more than a year, mapping and measuring how it changes as it is blasted by the sun's energy. Mission controllers had to use the gravity of Earth and Mars to give the probe a slingshot acceleration to meet its target on the right trajectory. Rosetta also had to be put into hibernation for more than two years to conserve power before being woken up successfully in January this year.
Scientists hope to learn more about the composition of comets and perhaps whether they brought water to the Earth or even the chemicals that make up the building blocks of life.