NASA to Launch New Science Mission to Asteroid 1999 RQ36
Well, it’s official. A new planetary science mission called OSIRIX-REx will be launched in 2016 to visit an asteroid in 2020, pluck up some samples from its surface, and return them to Earth. NASA just made the announcement about this mission, which has the lengthy name “Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer”, or OSIRIS-REx. It will be the first U.S. mission to carry samples from an asteroid back to Earth and studies of this asteroid will have far-reaching implications, not only in our understanding of their formation (and the information they carry about conditions in the early solar system), but also will help astronomers better predict the orbital paths of asteroids that come close to our planet.
So, what can an asteroid tell us? These chunks of leftover debris from the solar system’s formation some 4.5 billion years ago, contain the original material from the solar nebula from which the Sun and planets formed. Study that material and you can learn a huge amount of information about conditions in the nebula at the time the solar system was born. Along with comets, which were formed largely in the outer reaches of the solar system, asteroids are essentially treasure caches of material that “remembers” what it was like back in the early epochs of solar system history.
Asteroid 1999 RQ 36 is about the size of five football fields and is very likely rich in carbon and other elements that are useful in the creation of life. Organic molecules have been found in meteorite and comet samples, indicating some of life’s ingredients can be created in space. Scientists want to see if they also are present on RQ36.
Aside from doing a little “gardening” on the asteroid’s surface, the mission will also measure something called the “Yarkovsky effect.” It’s a small shove that the Sun’s radiation gives to an asteroid. The way it works is that an asteroid’s surface absorbs sunlight, just as Earth’s surface does. The asteroid’s surface then radiates that heat back out to space, and in the process, that gives a little “push” to the body. Now, this wouldn’t ordinarily be of much concern for asteroids that never get close to our planet. But, occasionally some do, and knowing the effect of the Sun’s warming on such a body helps astronomers predict their orbital paths (and possibly whether one could be a threat to our planet).
It’s interesting work because while we’ve studied most of the other planets and many of their moons, observations and visits to asteroids and comets are a bit rarer in planetary science.