NASA's asteroid Bennu samples hint at life on an ancient ocean planet

The recent analysis of asteroid Bennu samples, brought back to Earth by NASA's OSIRIS-REx spacecraft, has unveiled a fascinating possibility. Scientists believe these samples may originate from an “ancient ocean world,” potentially laying the groundwork for life as we know it.

Asteroid Bennu has become a focal point for scientists aiming to understand the early solar system and the origins of life on Earth. Preliminary results from the Bennu samples have sparked a groundbreaking theory that could redefine our understanding of the cosmos and the very essence of life’s building blocks.

In October, initial findings revealed significant discoveries. Researchers found that Bennu harbored large amounts of water and carbon – elements fundamental to the genesis of life. This revelation led scientists to speculate that asteroids like Bennu could have been instrumental in delivering the essential ingredients for life to Earth.

The University of Arizona's research team has taken this speculation further, suggesting that Bennu was once part of a water-rich planet that existed billions of years ago. Evidence comes from Bennu’s dark rocks, coated in a thin, bright crust, resembling materials found on Saturn’s moon Enceladus, known for its global ocean of salty liquid water beneath an icy shell.

The OSIRIS-REx mission, led by principal investigator Dante Lauretta, a planetary science professor at the University of Arizona, has been hailed as a monumental success. The spacecraft returned with almost twice the anticipated 60 grams of asteroid samples, providing an unprecedented opportunity for scientific study.

Lauretta’s hypothesis, based on unpublished results, suggests that the bright crust on Bennu’s rocks is composed of a rare calcium and magnesium-rich phosphate material. This material is comparable to that which spews from the vents on Enceladus’s surface, hinting at similar processes possibly occurring on Bennu’s parent body billions of years ago.

This theory is supported by similarities in mineralogy between Bennu and Enceladus, noted by Fabian Klenner, a postdoctoral researcher at the University of Washington. "There are indeed similarities between the mineralogy of Bennu and what has been found on Enceladus," Klenner told New Scientist. On Earth, these materials form through exothermic reactions when rock is pushed into a seabed and interacts with water, suggesting not only the presence of water but also conditions that could potentially support life.

While researchers are not claiming to have proof that life existed on Bennu's parent planet, the implications are profound. The analysis of the asteroid samples could contribute to our understanding of how life started, not just on Earth but potentially elsewhere in the universe. The similarities between Bennu’s and Enceladus’s mineralogy add an intriguing layer to the notion that life’s origins might be more common in the universe than previously thought.

As the scientific community awaits further analysis and published results, the initial findings from the OSIRIS-REx mission have already ignited a sense of wonder and possibility. The idea that Earth’s life-building elements could have been delivered from ancient, water-rich worlds like Bennu transforms our understanding of our place in the universe.

More about Asteroid Bennu

Asteroid Bennu is a fascinating celestial body classified as a near-Earth object. Bennu is a B-type asteroid, containing a significant amount of carbon along with various other minerals. This composition suggests that Bennu may hold clues to the early solar system’s chemistry.

With a diameter of approximately 500 meters, Bennu orbits the Sun every 1.2 years and comes relatively close to Earth every six years, making it an accessible target for space missions. Its surface is rugged and littered with boulders, making landing and sample collection a challenging task.

NASA’s OSIRIS-REx mission, launched in 2016, aimed to collect samples from Bennu’s surface and return them to Earth for analysis. In 2020, the spacecraft successfully touched down on Bennu, collected samples, and began its journey back to Earth.

Bennu is also of interest due to its potential impact threat to Earth. Calculations show a small chance Bennu could collide with Earth in the late 22nd century. Ongoing observations and studies aim to refine predictions and, if necessary, develop strategies to mitigate any potential impact threat.