I've been wondering this for quite a long time. Why do the planets of our solar system all orbit the sun in (more or less) a single plane? Is it a random coincidence, or are there physical forces that ...

A fresh study of the Kuiper Belt’s structure has revived that far-out question, pointing to a possible Earth-sized ...

In early 2016, two planetary scientists declared that a ghost planet is hiding in the depths of the solar system, well beyond the orbit of Pluto. Their claim, which they made based on the curious ...

Scientists have confirmed the existence of over 6,100 planets beyond the Solar System in the Milky Way. Something that has become clear pretty much from the very beginning of the search for exoplanets ...

In our Solar System, the planetary orbits all have a similar orientation. Their orbital planes vary by a few degrees, but roughly the planets all orbit in the same direction. This invariable plane, as ...

University of North Carolina researchers have recently discovered a baby exoplanet that could challenge our current understanding of how planets form in newly-minted solar systems. Designated IRAS ...

The Boeing X-37B reusable space plane returned to the Kennedy Space Center in Florida Saturday morning after a record 908 days in orbit around the planet. The space plane successfully landed at 5:22 a ...

Scientists have published new details about a scorching hot super-Earth where a year only lasts 17.5 hours and its surface is an ocean of lava. The 55 Cancri e — abbreviated 55 Cnc e — is roughly ...

Warm Jupiters are rewriting the rules of planet formation - showing eccentric orbits that stay strangely aligned with their stars.

Last week, the US Space Force posted a photo online from its uncrewed X-37B space plane's seventh mission, showing the orbital test vehicle above our planet in High Earth Orbit. Now that's a selfie ...

Whatever is the evolution of that system, the end result will need to have both same net energy and same net angular momentum as the original system. The energy is proportional to m/r , the momentum ...