Guide to Our Solar System

Planets of the Solar SystemOur solar system has one star, eight planets, several dwarf planets, a whole bunch of moons, lots of asteroids and comets, and a great many small chunks of ice, rock, and dust. Astronomers have known about the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn since ancient times. Other parts of the solar system were gradually discovered after the telescope was invented in 1608, including Uranus, Neptune, and Pluto.

More recently, astronomers continue to discover and calculate the orbits of smaller pieces among the asteroids, in orbit near Neptune's path, and beyond, then give them names from various ancient religions and mythologies. Pluto turns out to be one of a great many objects in the Kuiper Belt - like the asteroid belt, but beyond Neptune and mostly made of ice rather than rock. This led to a 2006 reclassification of all solar system objects that orbit the Sun, based on (roughly) size - or more precisely, certain mass and gravity thresholds required to do things like be round and clear other objects out of its orbital path.

Our solar system, then, consists of everything within the bounds of gravitational influence from the Sun. Aside from the more well-known parts nearer to Earth, there's the Kuiper belt and "scattered disc" which contains all the trans-Neptunian objects (with orbits that cross paths with Neptune), then the Oort cloud that goes all the way to the edge, where astronomers believe comets come from.

Latest Articles on Solar System
Our Dusty Solar System and the Phenomenon of Zodiacal Light

Have you ever spotted a faint oval glow near the horizon in spring or autumn? Then you may have seen the Zodiacal Light. Count yourself lucky! Most people spend their entire...

Size of Solar System vs. Size of Our Galaxy

Size is relative. How big is big? Well, if you have to travel from New York to Hong Kong that’s a pretty long trip, but it pales in comparison if you had to travel across...

Other Moons Of Our Solar System: Do They Too Have Phases?

If you watch our moon over the course of a month you will see it grow from a sliver of a crescent to a blazing spotlight in the night—the full moon. But is this elegant property...

Saturn's Moon Enceladus Grabs the Attention of Alien Life Hunters

The possible presence of water under the surface of Enceladus, one of Saturn's moons, has brought the satellite to the attention of exobiologists, a group of scientists dedicated...

Most Popular Articles on Solar System
  •  
    A Guide to the Inner Planets of Our Solar System

    Looking for information on the inner planets of our solar system? Which planets and what is their order from the Sun? Read on to find out about Mercury, Venus, Earth and Mars....

  •  
    Nothing But the Facts About Jupiter's Moon, Europa - I

    Just what you wanted to know about one of the most intriguing and shy places of our solar system: Europa, one of Jupiter's largest moons, but the smallest of the Galileans (Europa, Io, Callisto...

  •  
    Similarities Between Terrestrial and Jovian Planets

    All the planets in the Solar System can be grouped into two categories - terrestrial and Jovian planets. This article details the similarities between these very different types of planets....

  •  
    Nothing But the Facts about Claudius Ptolemy

    One of the most well known astronomers of the second century AD, Ptolemy has made significant contributions in the field of astronomy, geography, mathematics, astrology and physics....

  •  
    Nothing But The Facts - Tycho Brahe

    Tycho Brahe was one of the most notable astronomers in pre-telescopic times. His observations and instruments were critical in leading us to our modern-day understanding of the universe....

More About Solar System
Why Pluto Is No Longer A Planet

Pluto, the ninth planet from our Sun, has been demoted to a 'Dwarf Planet' and more recently reclassified as a "Plutoid". There are several reasons why the IAU has removed...

A Guide to the Solar System

Planets and planetoids, asteroids called Trojans and Centaurs, dwarf planets and plutoids, meteors, comets, extra terrestrial volcanoes and volcanoes made of ice! Moonscapes beautifully...