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

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of ...

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

Earliest inner solar system planetesimals shaped the inventory of moderately volatile elements in terrestrial planets.

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

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

The OSIRIS-REx mission returned to the sample to Earth in September of 2023, and these studies show that it contains amino ...

Astronomers discovered the gas giant planet — dubbed a "hot Jupiter " — in 2016, but have continued to investigate this ...

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But do other planets in the solar system have them too?

Mercury takes only 88 Earth days to orbit the sun.

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

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.