In an incredible feat involving decades of engineering, the European Space Agency (ESA) made history today by landing a spacecraft on a comet for the first time. The Rosetta space probe left Earth on an Ariane 5 rocket on March 2, 2004 and spent the next decade sling shotting around the solar system picking up speed using the gravity of planets and asteroids.
After a 31-month hybernation, Rosetta was awakened by her controllers on Earth to begin her primary mission: rendezvous with a comet. On August 6, 2014 Rosetta finally arrived at her destination...
Rosetta's destination is known as comet 67P/Churyumov-Gerasimenko. An enormous ball of rock and ice hurtling through space at more than 83,000 miles per hour (135,000 km per hour). How big is this sucker? In space, size is relative and can be difficult to judge. So here is a picture of the comet sitting on Los Angeles to give you a sense of scale
Upon arrival, Rosetta began orbiting the comet and collecting data to aid in the most difficult part of the mission -- landing its scientific payload on the surface of the comet. The lander, named Philae, is designed to study the comet's nucleus, composition, and activity level. After sifting through five possible landing sites, the ESA gave the all clear to proceed with separation of Rosetta and Philae. On November 12, 2014 the Philae descended to the comet and attempted to fire a harpoon system to attach to the surface. The harpoon failed, and the lander ultimately "bounced" on the surface several times before finally coming to a complete stop.
This marks the first time in history humanity has successfully landed a spacecraft on a comet. This feat comes only a few years after the first landing of a spacecraft on asteroid, which was achieved by the Hayabusa spacecraft and the Japanese Aerospace Exploration Agency (JAXA) in November of 2005. Apparently November is a good month to land on a celestial body! Comets are distinctly different from Asteroids in that they are made up of ice, dust and rocky material as opposed to the metallic makeup of most asteroids. Comets typically form far from the sun where their water stays frozen as ice. As they approach the sun with their elongated and extended orbits, the ice begins to vaporize and give comets their distinctive "tails". We will continue to post new photos and details from the mission as the Philae begins its science mission. Congratulations to the ESA on this amazing technological achievement!
NOVEMBER 17, 2014 UPDATE: After landing on the surface of the comet, Philae completed its science mission and returned data to the nearby Rosetta craft. However, it has been determined that Philae landed in the shade of a large cliff that may potentially block the solar energy necessary for Philae to continue. As of this writing, Philae had gone into hibernation mode in the hopes that as the comet approaches the sun, Philae may possibly be re-activated. Below is the first image ever taken from the surface of a comet!
The first image ever taken from the surface of a comet. Image Credit: European Space Agency.