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 ...

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

But of these planets, which is nearest to the sun? Mercury is the closest planet to the sun, followed by Venus, Earth, Mars, ...

Scientists have long struggled to accurately predict solar flares, but a recent breakthrough using NASA’s Solar Dynamics Observatory has uncovered a promising new sign: flickering coronal loops. These ...

Starting up again Saturday, a sweeping view of our solar system will glow in the night sky. The planetary alignment, or a ...

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

Long ago, a planetary object eight times the mass of Jupiter may have once visited the solar system and altered […] The post ...

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

Baker said that there are other astronomical events that may be more interesting than the parade of planets. Baker said Mars ...

Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but get a telescope and you can spot Neptune and Uranus.