The comet that the European Space Agency's Rosetta spacecraft has been chasing around the sun has a dark side. No, 67P isn't hiding any terrible secrets -- the southern hemisphere literally faces away from the sun during most of its 6.5-year-long solar orbit. Until recently, none of the cameras aboard Rosetta have been able to image it due to that utter lack of light, except for one -- the MIRO microwave instrument. NASA scientists behind the device have released a report on their observations, and lead author Mathieu Choukroun said "these unique data are telling us something very intriguing about the material just below its surface."
Source: NASA