Comets are believed to be the Solar System's building blocks. They also likely played a role in seeding the earth with ingredients necessary for supporting life such as water but there are many questions about these celestial objects that still remain unanswered.
It is for the purpose of unlocking the mysteries of comets that scientists from the European Space Agency, or ESA, launched Rosetta, a robotic space probe built to conduct a detailed study of the comet known as 67P/Churyumov-Gerasimenko.
The spacecraft was launched on March 2, 2004 with the objective of making it rendezvous with its target comet where it would study its nucleus and environment for about two years as well as land the Philae lander on its surface. The Philae is a robotic craft designed to touch down on comet 67P's surface and gather data about the 2.5-mile-wide comet's properties and composition.
After a decade of journey, Rosetta finally met comet 67P. On Wednesday, Aug. 6, the spacecraft finally marked its arrival at its target destination making it the first spacecraft to rendezvous with a comet. Rosetta is 100 kilometers from the surface of 67P but it is still edging closer.
"Arriving at the comet is really only just the beginning of an even bigger adventure, with greater challenges still to come as we learn how to operate in this unchartered environment, start to orbit and, eventually, land," said ESA's Rosetta spacecraft operations manager Sylvain Lodiot.
ESA's Rosetta project scientist Matt Taylor, said that over the next few months, they will start preparing for the landing of Rosetta's robotic lander Philae on the comet, which will be another first in space history.
Even at Rosetta's current trajectory, it already started to reveal information about the comet. The OSIRIS Rosetta Orbiter Imaging System has taken images that showed the activities on the comet were variable. The comet's coma, for instance, a nebulous envelope of dust and gas, became rapidly brighter and died down again in a matter of six weeks.
"We've arrived. Ten years we've been in the car waiting to get to scientific Disneyland, and we haven't even gotten out of the car yet and look at what's outside the window," senior scientific adviser with ESA's Directorate of Science and Robotic Exploration Mark McCaughrean said. "It's just astonishing."
Below are some of the images taken by Rosetta's OSIRIS of the Comet 67P:
