The European Space Agency's (ESA) Rosetta spacecraft is carrying the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) in outer space. On Thursday, the ESA released photos of comet 67P/Churyumov-Gerasimenko (Rosetta's Comet) pictured by OSIRIS.
The images of the comet were taken from a distance of 3,400 miles and are not highly resolved, but ESA scientists were able to develop a three-dimensional shape model of the comet's nucleus based on what OSIRIS captured. The scientists are also currently modeling the comet's three-dimensional shape to help get a better impression of its body shape. Comet 67P, it is believed, has a head connected to a larger body, with the connecting region being the 'neck.'
ESA's Rosetta spacecraft is poised to be the first mission to rendezvous with a comet, escort it as it orbits the sun, and deploy a lander to its surface. Its mission goals include: catching comet 67P and accompany it into the interior solar system; observing its nucleus and coma from close range; deploying Philae to make first controlled landing on a comet; measuring the increase in cometary activity during its closest position to the sun; and observing changes associated with the change in season as the comet leaves the inner solar system.
OSIRIS is a dual camera imaging system operating in the visible, near infrared and near ultraviolet wavelength ranges, according to its mission page. Its narrow angle camera is designed to produce high spatial resolution images of the comet's nucleus, whereas the wide angle camera will image dust and gas directly about the nucleus' surface. OSIRIS has a number of nucleus, dust, gas, asteroid flyby, Mars and Martian satellites flyby, and Earth/moon system flyby objectives.
NASA contributed three instruments to the Rosetta spacecraft: ALICE (a miniature UV imaging spectrograph), MIRO (the first microwave instrument sent into space), and IES (Ion and Electron Sensor). ALICE could help scientists determine the origin of the comet and find out more about its interstellar material, while MIRO will also observe its physical characteristics. The IES will look for examples of direct interaction between solar wind and the comet's nucleus.
The scientists hope to catch the comet sometime this year, but for now they'll have to work with whatever the Rosetta spacecraft and OSIRIS imaging system are providing them. You can read more about the three-dimensional model in this NASA news release.