Ever wondered how water got to Earth? Launched 7 years ago, NASA’s OSIRIS-REx mission capsule has finally landed back on our home planet, and might just be able to answer that question. The spacecraft visited Bennu, a 4.5 billion-year-old asteroid located merely 200 million miles away. It utilized a Touch-and-Go Sample Acquisition Mechanism, or TAGSAM, to collect space dust from the foreign object. By firing nitrogen gas at the surface of the rock, the craft disrupted particles which were then captured by surface contact pads and the TAGSAM head. Interestingly, the mechanism worked even better than expected. When the capsule returned to Earth on September 26, scientists were excited to find that extra debris sat in the cracks and base of the collection device. Immediately after its re-entry into our atmosphere, scientists rushed the capsule away to begin testing, with the results reported on October 11.
What researchers found provides important insight into the past and possible future of our planet. Scientists utilized electron microscopes, X-rays, and chemical analysis to understand the makeup of the particles brought back from Bennu. They found hydrated clay minerals, containing two of the most important building blocks of Earth: carbon and water. Thus, some scientists believe that this could explain how water got to Earth billions of years ago. In addition, the inclusion of carbon and sulfides in the rock could help explain how organic matter and even chemical compounds evolved on our planet. The sample’s composition also gives clues as to the makeup and future of the asteroid itself. The data already garnered from the investigation dropped Bennu’s risk of colliding with our planet from 1 in 2700 by the year 2200, to 1 in 1750 by 2300. Scientists will continue to use these observations to find ways of preventing the impact from ever occurring. Interestingly, since the sample was larger than expected, there are still many tests to be done and further examinations to be made. The debris represents “a whole treasure chest of extraterrestrial material,” according to the principal investigator, Dante Lauretta. Discoveries such as these do not come extremely often, as the missions take billions of dollars to fund and years to complete. While it may seem that the makeup of a far-off asteroid provides no important information regarding our own lives, this project could represent a major addition to the understanding of our planet and how it was formed.