Astronomers have identified a rare sednoid called Ammonite, an icy object beyond Neptune that offers new insight into the ...

Scientists say studying objects like Ammonite, despite their immense distance, offers valuable insight into the solar ...

Why Can't We Find Planet 9? Deep in the outer reaches of our solar system, far beyond Neptune and Pluto, something massive is ...

The origin of super-Earths and sub-Neptunes has been revealed in a system of four young planets that are dramatically losing ...

In the remote outer reaches of planetary systems, far beyond the orbit of known planets, enormous and mysterious worlds silently loop around their stars. Some drift as far as 10,000 times the distance ...

Planet 9 sits at the edge of scientific imagination, promising either an epic expansion of the Solar System or a lesson in ...

A new paper hypothesizes that there could be a Mars-sized object on the outskirts of the Kuiper Belt. If true, this would be distinct from the hypothesized Planet 9. Share on Facebook (opens in a new ...

The outer reaches of our Solar System continue to reveal a complex dynamical environment where the interplay of gravitational forces shapes the orbits of a myriad of distant bodies. Research in this ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course. When ...