Simulations show how the orbits of planets gravitationally scattered outward might be perturbed by passing stars within the star’s birth cluster, leading to the planets becoming stranded on wide ...

Scientists have found evidence of a previously-undetected dwarf planet at the edge of the solar system. The object, dubbed 2017 OF201, follows an extreme, oblong orbit, taking some 25,000 Earth years ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

The hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. Some astronomers ...

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural Sciences, has discovered an extraordinary trans-Neptunian object (TNO), ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

World views and the solar system -- Earth-centered world views in classical Europe -- Non-European world views -- Earth-centered world views in the Middle Ages and Renaissance -- Sun-centered and ...

All the planets orbit in the same flat plane — but it wasn’t always like that. The solar system began as a chaotic cloud of gas and dust collapsing under gravity. As it spun faster, it flattened into ...