Astronomers Spot Possible Primordial Cluster Beyond Neptune

Astronomers believe they may have discovered evidence of a mysterious structure far beyond Neptune, hidden deep inside the Kuiper Belt. This new finding could help scientists understand what the early solar system looked like billions of years ago. The study points to a dense group of icy objects that may have remained untouched since the beginning of the solar system. Although the research is still being reviewed, the possible implications are significant, reported Daily Galaxy.

The Kuiper Belt is often referred to as the solar system's "third region." It extends approximately 30 to 50 astronomical units (AU) from the Sun and contains icy remnants left behind during the solar system's formation.

According to NASA, this region lies beyond the orbit of Neptune, in the outer reaches of the solar system. Scientists estimate that millions of icy objects may exist here, many of which are over 60 miles (100 kilometres) across, while some, like Pluto, are larger than 600 miles (1,000 kilometres).

Like the asteroid belt, the Kuiper Belt is composed of fragments left over from incomplete planet formation. The difference is that while the asteroid belt is thin, the Kuiper Belt forms a thick, doughnut-like structure, shaped specifically by the gravity of the giant planets, including Neptune. This gravitational influence has caused the positions and distribution of objects in this region to change over time.

Despite long-term study, scientists still don't fully understand the structure of the Kuiper Belt. In 2011, researchers discovered that it isn't a uniform and linear region. A study published in The Astronomical Journal described it as a complex region with multiple substructures. The research also revealed that the classical belt contains multiple components that extend far beyond the traditionally described inner, core, and outer regions.

A team of scientists from Princeton University, led by astrophysicist Aamir Siraj, has identified a new structure at a distance of approximately 43 AU. They believe it could be a "primordial cluster"-a group of icy objects that has existed virtually unchanged since the early solar system. Siraj told New Scientist that the extremely calm and stable orbits of these objects indicate the region's antiquity and minimal disruption. According to them, this stability could provide important insights into the early history and evolution of the Solar System.

This discovery could also help explain how giant planets formed and gradually reached their current orbits. Scientists also suggest that this structure could hold insights into the early interstellar conditions the Solar System faced during its formation.

This study builds on a 2011 discovery that identified a "kernel" region of the Kuiper Belt, a region where objects' orbits remain stable and have low eccentricity over long periods of time. The new structure, located slightly inside this older kernel, shows even lower eccentricity, suggesting it may be even older and more stable.

According to Princeton researchers, the classical belt's structure should be understood as consisting of three major components, a "hot" component with a wide variation in orbits, and two "cold" components, called the core and the kernel. Now, the new structure discovered at 43 AU, with an even lower eccentricity, raises the possibility that an "inner kernel" may exist, possibly formed earlier and experiencing less disruption than other parts of the Kuiper Belt.