The Rosetta spacecraft took this image of comet 67P/Churyumov-Gerasimenko on 4 August 2014 from a distance of just 145 miles. ESA/Rosetta/NAVCAM hide caption

itoggle caption ESA/Rosetta/NAVCAM

Early days: NASA's International Sun-Earth Explorer C (also known as ISEE-3 and ICE) was undergoing testing and evaluation inside the Goddard Space Flight Center's dynamic test chamber when this photo was snapped in 1976. NASA hide caption

itoggle caption NASA

In 1986, the European spacecraft Giotto looked into the heart of Halley's Comet as it approached the sun. Data from Giotto's camera were used to generate this enhanced image of the comet's potato-shaped nucleus, measuring roughly 15 kilometers across. Halley Multicolor Camera Team/Giotto Project/ESA/NASA hide caption

itoggle caption Halley Multicolor Camera Team/Giotto Project/ESA/NASA

NASA took a series of images to create this "timelapse" view of comet ISON's trip around the sun. NASA hide caption

itoggle caption NASA