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

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

HD 20794 d completes its orbit just shy of two Earth years, placing it well within reach of conditions that might harbor life ...

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

On Feb. 24, from west to east, you can see Mercury, Saturn, Neptune, Venus, Uranus, Jupiter and Mars, all spanning 117.5°, ...

For much of January and February, you have the chance to see six planets in our solar system after dark, although two — Uranus and Neptune — will be hard to see without a telescope or high-powered ...

Aside from Earth, no planet in the solar system captures our imagination quite like Mars. The Red Planet is one of the few ...

When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

Jan. 15, 2025 — New observational data and simulation models have confirmed a new type of planet unlike anything found in the Solar System. This provides another piece of the puzzle to ...

However, this year a powerful new telescope is coming online that could prove once and for all that there really is a ninth planet in our Solar System. The same year that Pluto was ignominiously ...