An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

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

A new study suggests that a close encounter with a massive interstellar object, possibly eight times the mass of Jupiter, may have significantly altered the orbits of the four outer planets in our ...

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...

Despite common assumptions, the disk of our Solar System is warped, and the planets travel around the Sun in slightly eccentric (or oblong) orbits. Scientists now think that a mysterious object ...

A new study claims it is possible an "alien visitor" could have warped our solar system during its earliest years.

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun as the orbit of Mars.

The research, yet to be peer-reviewed, sheds light on what could have changed the orbits of several planets in the solar system.

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 planes. NASA artist’s conception of ...

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

Our Solar System is a carefully balanced celestial dance held together by a virtually perfect balance of gravity and inertia.