Revelations from the cosmos: Bennu may be the missing piece of a lost ocean planet

Revelations from the cosmos: Bennu may be the missing piece of a lost ocean planet
Bennu

In the vast, dark tapestry of space, objects from the dawn of the solar system silently orbit the sun, carrying secrets of our cosmic neighborhood’s early days. Among these celestial wanderers is Bennu, an asteroid that has recently captured the imagination and attention of the scientific community. This rocky body, a mere half-kilometer in diameter, may hold the keys to understanding the origins of life as we know it.

Bennu is not just any space rock. It is believed to be the remnant of a bygone oceanic planet, a fragment that survived the violent collisions and tumultuous reshaping of our solar system’s infancy. This asteroid, named after an ancient Egyptian deity associated with the sun and creation, could provide invaluable insights into the presence of water and organic materials outside Earth, raising profound questions about the ubiquity of life in the universe.

The narrative of Bennu as a piece of a former ocean world is not mere speculation; it is grounded in scientific observations. In its journey around the sun, this asteroid has revealed characteristics that betray its watery past. Studies suggest that its surface is speckled with hydrated minerals, remnants of clay that could only form in the presence of water. These minerals, which have been found in similar forms on Mars and other celestial bodies, are tantalizing indicators that Bennu’s parent body once hosted vast amounts of water.

The plot thickens when considering the asteroid’s organic content. Bennu is rich in carbon, the backbone element of all known life. Coupled with the presence of water, this carbon abundance paints a picture of an environment where organic chemistry could have flourished. The asteroid’s regolith, the layer of loose rocks and dust covering its surface, is thought to be a treasure trove of complex organic molecules. These molecules could date back to the earliest epochs of our solar system, offering a pristine window into the chemical processes that may have led to the emergence of life.

Researchers are particularly interested in the amino acids that might be present on Bennu. These organic compounds are the building blocks of proteins, the workhorses of all living cells. The discovery of amino acids on Bennu could suggest that the ingredients for life are not only common in the solar system but have also been around since its formation.

The drama of Bennu does not end with its composition. The asteroid’s orbit brings it tantalizingly close to Earth every six years, earning it the classification of a potentially hazardous object. Despite the low probability of an impact, the close encounters provide an unprecedented opportunity for scientists to study Bennu up close and personal.

NASA’s OSIRIS-REx mission capitalized on such an opportunity. The spacecraft, launched in 2016, traveled to Bennu, surveyed its surface, and collected samples. These samples, which are en route back to Earth, are expected to arrive in 2023. The anticipation within the scientific community is palpable, as these grains of space dust could rewrite our understanding of the solar system’s history.