NASA is planning a mission to collect a piece of an asteroid and return it to Earth in order to discover clues to the formation of the solar system and possibly, the origins of life.
Called the OSIRIS-REx, for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, the probe is scheduled to launch in 2016. It will fly to an asteroid called 1999 RQ36, an asteroid that orbits roughly between Earth and Mars. After spending about a year studying the asteroid, it will return the samples to Earth by 2023.
Scientists are eager to get a piece of it because it likely hasn't changed much in the billions of years since the solar system was formed. That could offer clues as to why planets form the way they do.
The asteroid is also rich in carbon, and possibly other organic molecules (organic molecules aren't necessarily formed by living things; the term just means they contain chains of carbon atoms). As similar molecules have been found in meteorites, analyzing a piece of the asteroid would mean getting a look at what the material is like before being heated up by entering the earth's atmosphere. Some scientists think that such molecules could have seeded the early Earth, setting the stage for the complex carbon chemistry that led to life.
Asteroid 1999 RQ36 is special for another reason: it has a 1 in 1,800 chance of hitting the Earth in the year 2182. Since it is a large object, some 575 meters across, such an impact would be devastating.
OSIRIS-REx will usher in a new era of planetary exploration, said Dante Lauretta, the mission's deputy principal investigator and an associate professor at the UA's Lunar and Planetary Laboratory, in a statement. For the first time in space-exploration history, a mission will travel to, and return pristine samples of a carbonaceous asteroid with known geologic context. Such samples are critical to understanding the origin of the solar system, Earth, and life.
1999 RQ36 orbits the sun every 1.2 years, crossing the Earth's orbit every September. Its shape and rotation rate are well known, allowing OSIRIS-REx to make a safe, albeit short, touchdown.
Our spacecraft will sneak up to RQ36 over the course of weeks, Lauretta said. Once the two objects are traveling in sync, OSIRIS-REx will extend its sample collector, touch the surface for five seconds, collect well over 60 grams of sample, and get out of there.
Using an injection of nitrogen, the OSIRIS-REx sample-collecting device will stir up dirt and small gravel to be captured and sealed for return to Earth. The samples are returned to the surface of the Earth using equipment and procedures similar to the Stardust mission, which returned samples from comet Wild 2 in 2006.