Asteroid samples collected from Bennu by NASA’s OSIRIS-REx mission have revealed fascinating details about the early solar system and the history of water in space.
These samples, the largest ever returned to Earth from an asteroid, provide scientists with invaluable data about the conditions and processes that existed billions of years ago.
The significance of Bennu and the OSIRIS-REx mission
Nine months after NASA’s OSIRIS-REx mission returned samples from the asteroid Bennu, scientists are uncovering surprising details about the asteroid’s past. Bennu was chosen for the mission because of its proximity to Earth, manageable size, and presence of organic molecules.
These attributes make Bennu an ideal candidate for studying the primordial world materials of the solar system. Returning samples to Earth allows for more comprehensive analysis than can be done remotely. As stated in Universe Today, “Returning samples to Earth is the best and most complete way to study asteroids.”
Bennu is a B-type asteroid, rich in carbonaceous materials that are key to understanding the early solar system. These materials are essential for tracing the origin and formation of the solar system. Dante Lauretta, Principal Investigator of the project The OSIRIS-REx missionexplained the meaning: “Bennu may once have been part of a wetter world.”
Analysis of Bennu samples
The samples, weighing about 120 grams, were carefully analyzed using a variety of advanced techniques, including plasma mass spectrometry, infrared spectrometry and X-ray computed tomography. The results revealed a complex composition minerals and organic compounds, some of which were unexpected. The pristine nature of these samples means that they have not undergone melting and resolidification and have retained their original state from billions of years ago.
One of the most interesting findings is the presence serpentine and other clay minerals, similar to those found on Earth’s mid-ocean ridges. These minerals suggest that Bennu may have had interactions with water in the past. Dante Lauretta highlighted the unexpected discovery: “The biggest surprise to me is that a subset of the particles are covered by salty crusts. We probably know it well in Arizona. If you have hard water and you’re creating those white, crusty salts that clog your shower head and faucets, that’s the same kind of process we’re seeing in these asteroid samples. You had a salty liquid and it evaporated and left behind what we call evaporated minerals.”
Discoveries and implications
The discovery of these minerals suggests that Bennu may have experienced it hydrothermal processes, similar to those at the bottom of Earth’s oceans. The finding is significant because it suggests that water, a critical ingredient for life, may have been more widespread in the early solar system than previously thought. The presence of these clay minerals on Bennu parallels processes observed on Earth, providing a fascinating comparison and deeper understanding of planetary formation and evolution.
Moreover, presence water-soluble phosphates in the Bennu sample is particularly notable. These compounds are vital components of biochemistry and are found throughout the Earth’s biosphere. Their discovery on Bennu opens new avenues for understanding the distribution of life-supporting chemicals in the solar system. According to a study published in Meteoritics and Planetary Science, “The presence and state of phosphates, along with other elements and compounds, on Bennu suggests a watery past for the asteroid.”
Research by Dante S. Lauretta and his team has provided a comprehensive overview of the specimen, which is now available for other researchers to request and study. “Finally having the opportunity to dive into Bennu’s OSIRIS-REx sample after all these years is incredibly exciting,” Lauretta said in a press release. “This breakthrough not only answers long-standing questions about the early solar system, but also opens up new avenues of investigation into the formation of Earth as a habitable planet.”
