Rosetta, a European spacecraft, arrived at Comet 67P/Churyumov-Gerasimenko on 6 August, carrying the closest approach of an observatory to one of these visitors from the outskirts of the Solar System.

Comet 67P/Churyumov-Gerasimenko is currently racing toward the Sun, heating up as it approaches our home star. As it draws closer to the center of the solar system, energy from the Sun will start warming the icy surface of the comet, releasing the material as gases and particles of dust, forming one or more tails.

Rosetta will follow the minor body as it falls toward its closest approach to the Sun.

Philae, a tiny lander now attached to the Rosetta spacecraft, will be released on its own mission in November 2014. If successful, that craft will become the first vehicle to ever touch down on the surface of a comet.

"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," Sylvain Lodiot, Rosetta spacecraft operations manager at ESA, said.

Mission managers plan to identify up to five different possible landing spots on the comet by late August, before coming to a final decision in the middle of September.

The Rosetta spacecraft is roughly 250 million miles from Earth, between the orbits of Mars and Jupiter.

In 1986, the European Space Agency (ESA) launched a mission to Halley's Comet, known as Giotto. This first planetary mission ever from the agency inspired the organization to develop a more advanced spacecraft, which became the Rosetta project.

Comets are believed to contain some of the oldest matter in the solar system. Vast numbers of the bodies, left over from billions of years ago, reside in slow, sweeping orbits around the distant sun. When nudged through collision or gravitation, these bodies can start dropping toward the distant star. Those that are not destroyed by their close encounter with the Sun can be sent back out to the outer sphere of the solar system once more, beginning the process anew.

Researching these small, icy bodies could provide astronomers with information they need to uncover mysteries about the formation of our sun and its attendant retinue of planets.

The comet was named after a pair of astronomers from the Ukraine who discovered the object.

Comet 67P/Churyumov-Gerasimenko will make its closest approach to the Sun in August 2015, and the Rosetta mission will come to an end later that year. The comet will not be visible to people on Earth, without the aid of a telescope.