Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being classified as a dwarf planet. However, out beyond Neptune there could be ...

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 ...

New findings offer clues about the ancient origins of asteroids and their potential role in the formation of terrestrial ...

New research shows that star activity can distort exoplanet measurements, affecting size, temperature, and atmosphere ...

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 ...

To better understand why the planets have variable compositions ... to the formation of the gas and ice giants in the outer solar system. This first-order model of planetary growth in the solar ...

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 ...

Stand out dates include January 31 when ... you’re peering into the vast expanse of our solar system. Each planet orbits the Sun at vastly different distances—Mercury sits about 36 million ...

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 ...