We know more about comets than ever before thanks to the epic efforts of the European Space Agency's Rosetta spacecraft. Launched in 2004, Rosetta arrived at Comet 67P/Churyumov-Gerasimenko in mid-2014 and spent over two years in close-up study of the hurtling space object.
The mission finally came to a close September 30 as the ESA sent Rosetta down to settle on the comet's surface. These are Rosetta's final images from the descent.
This mosaic shows the sequence of images Rosetta took prior to impact. The craft joins its famously lost (and found) lander Philae on the comet. Rosetta is no longer capable of communication with Earth.
Rosetta's navigation camera received one last assignment when the ESA snapped a series of final images to make sure the spacecraft was on course for the proper landing site on the comet. This picture shows a view from 9.6 miles (15.4 kilometers) above the surface.
Rosetta's dramatic descent images start with this look at Comet 67P's surface as seen from 9.9 miles (16 kilometers) above. The craggy and dusty comet is the spacecraft's final resting place.
The mission end came at a time when the comet and Rosetta were both traveling far from the sun, leaving the spacecraft with dwindling power and raising the specter of major communications disruptions. It was time to say goodbye.
Rosetta's OSIRIS wide-angle camera captured this look at Comet 67P etched against the black of space. "It shows the target impact region just coming in to view in the lower left -- look for the distinctive shape of the Ma'at pits," notes the ESA.
Rosetta's OSIRIS narrow-angle camera took part in recording the mission finale with this closer look at the craggy surface of Comet 67P/Churyumov-Gerasimenko from 7.3 miles (11.7 kilometers) above. The comet's "neck" region is home to both smooth and rough terrain areas, both of which are visible here.
Comet 67P looms large in this image, one of the final views the ESA's Rosetta spacecraft sent back to Earth. "The image shows a portion of the small comet lobe, with portion of the rough Hathor region (top right) and smoother Ma'at (bottom left)," says the ESA.
The comet-studying Rosetta spacecraft is a mere handful of miles above the surface of 67P in this image taken by the OSIRIS narrow-angle camera. Rosetta's final resting place is on the small lobe of the two-lobed comet. The actual landing site is just outside of view below the picture's lower edge.
The comet just keeps getting closer in the final sequence of images from Rosetta's cameras. The ESA's groundbreaking spacecraft spent a little over two years studying Comet 67P/Churyumov-Gerasimenko after first launching on its cosmic journey in 2004.
Rosetta's dramatic final image before impact on Comet 67P shows a blurry landscape of dust and boulders from a mere 66 feet (20 meters) away. The ESA amended the original estimate of 167 feet (51 meters) above the surface.
Rosetta's legacy lies not only in images, but also in a wealth of scientific information that has changed the way we view comets.
"Previously, they were pictured as dirty ice balls -- or, as some prefer, icy dust balls -- but now we know them, or at least this one, to be geologically complex worlds where a myriad of processes are at work creating the incredible surface structure and activity of the comet," says Rosetta mission scientist Eberhard Grün.
Rosetta will be missed, but it did its job in spectacular fashion and now gets a well-deserved rest aboard its comet buddy.