A Neptune-sized planet, TOI-3261 b, makes a scorchingly close orbit around its host star. Only the fourth object of its kind ever found, the planet could reveal clues as to how planets such as ...

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 ...

While planets circle the sun in what's called and heliocentric orbit, they rarely fall together in what appears to the human ...

Kuiper Belt, well past the orbit of Neptune (artistic illustration). There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond ...

and it was only discovered in 1846 after calculations of Uranus's orbit suggested there was an as-yet unknown planet affecting it gravitationally. Since then, the planet has only been visited once by ...

It probably spent nearly all of the past 4.5 billion years in a deep freeze beyond Neptune, inside the comet Wild 2 (pronounced VILT-two). Decades ago Wild 2 somehow got nudged into an orbit that ...

In general, as the distance from the Sun increases: the temperature decreases, eg Mercury is 430°C whereas Neptune is –200°C the time taken to orbit the Sun increases, eg Mercury orbits once ...

Sky watchers are in for a treat this month as the stars align to give amateurs a shot to see six planets at once.

"A parade of planets, also sometimes referred to as a planetary alignment, is when several planets in our solar system appear ...