After a journey that took more than a decade, the world is scheduled to witness a first when the European Space Agency’s Rosetta mission attempts to land a small spacecraft on the surface of a comet. The attempt will take place on Wednesday, at speeds of about 34,000 miles per hour.
The mission is a potential breakthrough in the study of comets. These chunks of ice and dust are leftovers from the formation of planets, often considered space “icebergs” given their age and distance from the sun. The water that resides in comets is likely the key to sustaining future deep-space missions—a celestial gasoline station, in a sense. Beyond water, comets such as the now-famous 67P are thought to harbor complex organic molecules, some of the ingredients needed for the formation of intelligent life.
“I think that humans have to go into space more and take ownership of the solar system,” says Denton Ebel, chairman of the division of physical sciences at the American Museum of Natural History, calling efforts such as Rosetta “the logical next step” of human space exploration.
There is yet another reason underlying the space agency’s financial and engineering feat: to prove it’s possible. Before attempting to land on the comet, the spacecraft will have whipped around the earth three times, followed by Mars, to obtain the necessary gravitational acceleration to rendezvous with a comet. The Rosetta craft will discharge a 220-pound landing probe, called Philae, to settle in a relatively clear spot only about 1/3-mile square.
“It’s technically one of the most difficult missions ever,” Ebel says. “This mission is amazingly ambitious.”
Other reasons to visit a comet include getting a better understanding of how massive space rocks are constructed, which could prove crucial if future earthlings ever need to intercept and prevent a doomsday scenario. There is also the issue of manned deep-space exploration and using the abundant resources found in comets and asteroids, mainly water and noxious gases but also precious metals. “How is the water locked up in a comet? We don’t really understand that at all,” Ebel says.
Future space explorers will almost certainly need to stop for water en route. Bring water from earth into space costs about $23,000 per pound, according to Planetary Resources, which plans to mine asteroids. The hydrogen and oxygen in water is also the basis for rocket fuel that will be produced in space.
The Rosetta mission was launched in March 2004 and reached Comet 67P/Churyumov-Gerasimenko on Aug. 6, where it has been orbiting about 14 miles from the surface. The comet is about 2.5 miles across at its widest point.
Confirmation of the Philae lander’s fate is expected to arrive at about 10:36 a.m. EST at the mission control in Darmstadt, Germany, following a seven-hour descent to the comet. The agency has deployed a full array of social media to chronicle the landing, including collaborating with a futuristic film dramatization starring Game of Thrones actor Aidan Gillan and a soundtrack of the sub-audible magnetic emissions from the comet, sped up so they can be heard. Come Wednesday, there will be tweets.