Rosetta Spacecraft

Rosetta, after a 10-year space voyage, went to its final resting place this morning during a controlled collision with the object of its affection, Comet 67P.

In 2014, Rosetta sent its only companion, Philae, a small comet-lander to the comet surface. Philae was intended to live on the comet for the life of the mission, however, it was critically damaged on landing and managed to send data to Rosetta for more than two days before its batteries went dead.

Together, Rosetta and Philae sent back over 100,000 photographs and stacks of scientific data to Earth.

In heroic fashion, Rosetta sent high-resolution photographs to Earth until it reached its final resting place.

The photograph below is the last full-field photograph sent by Rosetta as it was about 29 km away from the comet and approaching at a velocity of 1 meter per second – about walking speed.

Comet 67P

Comet 67P is a small comet, only about 2.5 miles long and shaped like a rubber duck with two lobes connected at the neck. It orbits the Sun every 6.5 years at a velocity of 84,000 miles per hour.

As Rosetta nuzzles into its final resting place, we should remember what Rosetta did for our understanding of our solar system. It confirmed that comets are made from a low-density collection of frozen water (ice), stone, rock dust, ammonia, carbon dioxide, and methane.

Rosetta re-defined comets as “snowy-dirtballs” made from the gentle collisions of low-density material left in space after the massive planets had formed about 4 billion years ago. The Sun causes ice on 67P to sublimate in forceful vents that eject water vapor and dust into space forming the comet’s tail.

Rosetta was a Cooperative Effort

As we say good night to Rosetta, we might reflect on the incredible degree of technical sophistication and human effort required to put this worthy machine into orbit around a small comet located about 40 million miles away from Earth and then ride with that comet for two years as it flew by the Sun.

The mission was a combined effort of 14 European nations and the United States. We can only hope for similar levels of cooperation and sophistication as we deal with technical and non-technical issues profoundly affecting our future.

This is the final transmission from Rosetta.