Produced by: Tarun Mishra Designed by: Manoj Kumar
On September 24, 2023, NASA’s OSIRIS-REx spacecraft returned to Earth with a capsule containing pristine samples from the near-Earth asteroid Bennu. The mission involved a seven-year roundtrip journey through the solar system.
Credit : NASA
The samples, weighing approximately 120 grams, are expected to provide insights into the history of our solar system and the origins of life on Earth. Scientists are particularly interested in finding prebiotic molecules and other essential ingredients like water.
Dante Lauretta, principal investigator for OSIRIS-REx at the University of Arizona, stated that the returned sample is the largest reservoir of unaltered asteroid material currently on Earth.
Early studies of the samples revealed evidence of carbon and water. However, a recent unexpected discovery of magnesium-sodium phosphate in the samples has captured scientists’ attention.
This compound, composed of magnesium, sodium, and phosphate ions, was not detected in the OSIRIS-REx probe’s remote sensing data before sample collection. Its presence hints that Bennu may have originated from a long-gone, primitive ocean world.
The presence of phosphates and other elements on Bennu suggests the asteroid may have a watery past. This finding requires further investigation to understand Bennu’s history and its potential connections to wetter celestial bodies.
OSIRIS-REx collected the samples using its Touch-and-Go Sample Acquisition Mechanism (TAGSAM) from a site named Nightingale in Bennu’s Hokioi Crater. The site is located in the asteroid’s northern hemisphere.
Further analysis revealed that the main component of the regolith sample is magnesium-bearing phyllosilicates, such as serpentine and smectite. These minerals are typically found at mid-ocean ridges on Earth, providing clues about Bennu’s aqueous environment and geological past.
Bennu’s surface materials contain carbon, nitrogen, and organic compounds, essential for life as we know it. The study of these samples may reveal more about the prebiotic chemistry that contributed to the emergence of life on Earth.
The findings highlight the importance of collecting and studying asteroid material to understand solar system formation and evolution. The full implications of the sample are still being investigated, with researchers anticipating further discoveries. The study was published in the journal Meteoritics & Planetary Science on June 26.