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SOLAR SYSTEM · Your travel guide to the Solar System ·

The Solar System

DEFINITION

The Solar System is made up of the Sun, the planets, their moons, asteroids and comets

REASONS TO VISIT

  • Experience an amazing variety of worlds
  • Run the gauntlet of floating rocks and boulders in the asteroid belt
  • Encounter the icy comets that wander through the outer Solar System
 
Solar System Jigsaw
Solar System Jigsaw
Can you
build the Solar System?

WHAT TO SEE


The Sun
The Sun is a star that lives at the centre of the Solar System. Its huge gravity holds the planets in place.

The planets
The planets all revolve around the Sun. There are eight in total - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Moons
Moons rotate around their parent planet. Earth has one moon, but some planets have over 50. Only Mercury and Venus do not have any moons.

Asteroids
Asteroids are rocky bits of debris up to 1,000km (620 miles) across. Most live in the asteroid belt between Mars and Jupiter. They are the remnants from early planets that collided and were torn apart.

Comets
Comets are dirty snowballs of ice and dust that revolve around the Sun in long orbits. When they approach the Sun they heat up, leaving a trail of gas behind them, which looks like a tail.

Recent comets to fly-by the Sun include Halley, Hale-Bopp and Ikeya-Zhang.


LOCAL HISTORY


Our Solar System began forming about 4.6 billion years ago from a swirling gas cloud. Over time, the gas cooled and clumped together to form large bodies called 'protoplanets'. The 'left over' material became comets, roaming silently through the Solar System.

Learn more about how the Solar System was built

Eventually after 100 million years, the enormous ball of gas at the centre of the cloud overheated and exploded in a huge nuclear reaction. The Sun was born.

Follow the life and death of a star

People of the ancient world observed the movements of the planets and thought they were wandering stars. This is why the Greeks gave them the name planetes or 'wanderers'.

TRAVEL INFORMATION


From the Earth
You can sometimes spot the planets in the night sky from Earth. Unlike the Sun and the other stars, they don't produce their own light. They shine because they are reflecting the Sun's light.

Before you leave
Be prepared to physically change during your journey through the Solar System. As you visit each planet, your age and weight will be different! This is due to the different atmospheric pressure, gravity and orbits of the planets around the Sun.

THE PLANETS


The rocky planets
The four planets closest to the Sun are:
  • Mercury
  • Venus
  • Earth
  • Mars

  • These are called the 'rocky' or 'terrestrial' planets. They are small by planetary standards and made of similar materials to the Earth.

    The gas giants
    The next four planets are:

  • Jupiter
  • Saturn
  • Uranus
  • Neptune

  • They are known as the 'gas giants'. They all have rings and lots of moons. The gas giants are made up mostly of hydrogen, helium, frozen water, ammonia, methane, and carbon monoxide.

    The Dwarf Planets
    The International Astronomical Union redefined the term planet in August 2006, so Pluto is now classified as a dwarf planet. There are two other dwarf planets in the solar system, Ceres and Eris.

    More from BBC

    BBC Space - Exploration
    The history and future of planetary missions

    h2g2 - Solar System entry
    The guide to Life, the Universe and Everything, written by you

    Go further

    SEDS - The Nine Planets
    In-depth site on the structure, mythology and exploration of the Solar System

    NASA - Planetary Photojournal
    Fantastic pictures of the planets

    The Planetary Society
    Society founded by Carl Sagan to promote exploration of the planets

    Space Kids - Solar System
    News, games and homework help on the planets

    Scale Model of the Solar System
    Compare the size and distance of the planets and Sun

    Sun Earth Plan.net
    Up-to-date news and scientific information about the Sun, planets and atmosphere


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