Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

As planetary systems evolve, gravitational interactions between planets can fling some of them into eccentric elliptical orbits around the host star, or even out of the system altogether. Smaller ...

A massive interstellar object passing through our solar system during its formative years likely altered the orbits of planets into trajectories observed today, a new study says. Interactions with ...

Gravity not only maintains the stability of these orbits but also influences phenomena like tides on Earth, caused by the moon's gravitational pull. The paper, authored by David Jewitt from the ...

The shape of a planet's orbit is one of its fundamental properties, along with its size and distance from its host star. Earth has a nearly circular orbit, but some planets outside our solar system, ...

“The Sun’s death is not an event the planets will quietly survive—it is the trigger for their orbital undoing.” Reading time 3 minutes Our Sun is just like any other star. That is, eventually the Sun ...

A new discovery finds that, even in “pristine” solar systems, planets exhibit a bit of a tilt. Scientists have long puzzled over why all of the planets in Earth’s solar system have slightly slanted ...

EVANSTON, Ill. — Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason to believe that our solar system was anything special in the universe. But, ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...