New minor planet discovered outside Pluto; details inside

Astronomers have discovered a new small planet far from Pluto, expanding our understanding of the solar system's far reaches. Nicknamed 2017 OF201 , this trans-Neptunian object (TNO) is one of the largest distant bodies ever discovered, telling us something new about the Kuiper Belt and the outer reaches of our cosmic neighbourhood.

A giant in the outer solar system
2017 OF201 was found in archival telescope observations and officially named by the International Astronomical Union's Minor Planet Center. Most fascinating about the object, perhaps, is its enormous size and unusual orbit. Measured estimates render it between 470 to 820 kilometres (roughly 290 to 510 miles) in diameter, putting it in the size of known dwarf planets and big asteroids like Ceres.

Its orbit is extremely elongated, swinging it as close as 45 astronomical units (AU) from the Sun — roughly 45 times the distance from Earth to the Sun — to an astonishing 838 AU at its farthest distance. To put that into perspective, Neptune orbits at approximately 30 AU. This enormous elliptical orbit makes 2017 OF201 an extreme trans-Neptunian object (ETNO), a group that contains bodies living in the outermost zones of the solar system.

The Kuiper Belt where Pluto and other frozen objects are found remains a mystery area with remnants of early solar system debris over 4.5 billion years ago. The 2017 OF201 discovery helps astronomers to make sense of how the objects came to be and how they evolved and formed, gaining data about the initial state in the solar system.

What this does for planet nine and solar system science

The 2017 OF201 find is under ongoing research into whether a ninth world is concealed in the distance past Neptune. The theoretically mentioned "Planet Nine" would be gravitationally dominant over the distances travelled by a cluster of ETNOs. While 2017 OF201's orbit is not an exact match for the predicted course of Planet Nine, each new object found in the outer reaches of the solar system provides valuable information that helps astronomers fine-tune their models and theories.

Besides the Planet Nine hypothesis, tracking and observing distant objects like 2017 OF201 helps researchers gain more information about the solar system's periphery structure and dynamics. These objects are cosmic fossils that preserve the history of planetary migration, collisions, and other historic phenomena.

Upcoming observatories like the Vera C. Rubin Observatory will propel quicker discovery of distant solar system objects and give us a better vision of these distant regions. Today's exploration will be able to shed more light on the edges of the solar system and the workings that define our local space neighbourhood.

In total, 2017 OF201 is an important addition to the portfolio of known trans-Neptunian objects. It not only fills the holes in what we know now but also pushes the limits of how far we know the solar system stretches to go, and sets the stage for promising paths to be pursued in the future.

image credits: Canva