The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

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.

Scientists believe that two asteroids might be fragments of long-lost "planetary embryos" from the early solar system.

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

This may explain the strange properties of the orbits of our solar system's planets, which are not quite perfectly circular, and all lie on slightly different ... to figure out how the orbits ...

Most of the information we have about planets beyond our solar system (exoplanets ... as it will seem to block out more of the star's light, or they might infer the planet is hotter than it ...

Canadian astronomers have taken an extraordinary step in understanding how planets are born, using the James Webb Space ...

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But do other planets in the solar system have them too?

then it could disprove the notion that there is a ninth planet lurking out in the darkness of our Solar System beyong Neptune. But should the orbits of the new objects follow the trend ...