Explore the Solar System

Why this world matters

The Sun is the engine of the Solar System. It controls orbits, warms planets, drives space weather and sends out charged particles known as the solar wind.

Interesting facts

• Light from the Sun takes about 8 minutes to reach Earth.
• Sunspots are cooler, darker magnetic regions on the Sun’s visible surface.
• Solar flares can release huge bursts of energy into space.
• The Sun is mostly hydrogen and helium.

Why this world matters

Mercury helps us understand what a small rocky world looks like when it has little protection from space impacts and solar radiation.

Interesting facts

• A year on Mercury lasts only 88 Earth days.
• Mercury has extreme day and night temperature changes.
• Its surface looks similar to the Moon because it is covered in impact craters.
• There is ice hidden in permanently shadowed craters near its poles.

Why this world matters

Venus is one of the best examples for learning about atmospheres, greenhouse heating and how planets can develop very differently.

Interesting facts

• Venus is hotter than Mercury even though Mercury is closer to the Sun.
• Its clouds contain sulfuric acid.
• Venus rotates backwards compared with most planets.
• Radar is used to map its surface because clouds hide the ground.

Why this world matters

Earth is our reference point. When we study other worlds, we compare them with Earth to understand life, climate, water and change.

Interesting facts

• About 71 percent of Earth’s surface is covered by water.
• Earth’s magnetic field helps protect it from charged particles from the Sun.
• Plate tectonics constantly reshapes the surface.
• The Moon helps stabilise Earth’s tilt.

Why this world matters

The Moon is close enough to observe from Earth and preserves a long record of impacts and ancient volcanic activity.

Interesting facts

• The dark patches are called maria, meaning seas, but they are ancient lava plains.
• The Moon is slowly moving away from Earth.
• Only one side usually faces Earth because the Moon is tidally locked.
• Moon craters last a very long time because there is no rain or wind like Earth.

Why this world matters

Mars is one of the best places to study whether life could once have existed beyond Earth.

Interesting facts

• Olympus Mons is the tallest volcano known in the Solar System.
• Valles Marineris is much larger than the Grand Canyon.
• Mars has seasons because its axis is tilted.
• Its red colour mostly comes from iron oxide, similar to rust.

Why this world matters

Jupiter’s gravity shaped much of the Solar System, and its moons are worlds worth studying in their own right.

Interesting facts

• The Great Red Spot is a giant storm larger than Earth.
• Jupiter has no solid surface like Earth.
• Its magnetic field is extremely powerful.
• The four largest moons are Io, Europa, Ganymede and Callisto.

Why this world matters

Saturn shows how beautiful and complex ring systems can be. Its moon Titan is also one of the most fascinating worlds we know.

Interesting facts

• Saturn’s rings are wide but very thin compared with the planet.
• Saturn is less dense than water overall.
• It has strong winds and cloud bands.
• Titan has a thick atmosphere and methane lakes.

Why this world matters

Uranus is useful for learning about rotation, planetary tilt, seasons and how planets can behave in unexpected ways.

Interesting facts

• Uranus spins almost on its side.
• Its colour comes mainly from methane in the atmosphere.
• It has faint rings.
• A season on Uranus lasts for many Earth years.

Why this world matters

Neptune shows that even planets far from the Sun can still have active weather and powerful storms.

Interesting facts

• Neptune was predicted mathematically before it was directly observed.
• Its winds are among the fastest known in the Solar System.
• Triton orbits Neptune in the opposite direction to Neptune’s rotation.
• Neptune receives far less sunlight than Earth but still has active weather.

Why this world matters

Pluto changed how scientists classify planets and showed that small distant worlds can be geologically interesting.

Interesting facts

• Pluto’s bright heart shaped region is called Tombaugh Regio.
• Sputnik Planitia is a huge plain of nitrogen ice.
• Charon is very large compared with Pluto.
• New Horizons flew past Pluto in 2015.

Why this world matters

Ceres connects rocky asteroids with icy worlds and helps scientists study water, salts and small planet formation.

Interesting facts

• Ceres was once classified as a planet.
• It was later classed as an asteroid, then as a dwarf planet.
• The bright spots in Occator Crater are salt deposits.
• NASA’s Dawn spacecraft orbited Ceres.

Why this world matters

Eris matters because it forced astronomers to define what a planet actually is.

Interesting facts

• Eris is one of the most massive known dwarf planets.
• It has a moon called Dysnomia.
• Its icy surface reflects a lot of sunlight.
• Its orbit is much more stretched than the main planets.

Why this world matters

Haumea shows how rotation can affect the shape of a world.

Interesting facts

• Haumea completes one rotation in only a few hours.
• Its fast spin gives it an elongated shape.
• It has moons.
• It also has a ring, which is unusual for a dwarf planet.

Why this world matters

Makemake helps scientists understand icy outer Solar System objects beyond Neptune.

Interesting facts

• Makemake is one of the larger known dwarf planets.
• It is very cold and very distant.
• Its surface is bright because of reflective ices.
• It has a small known moon.

Why this world matters

Io shows how gravity can heat a moon from the inside through tidal flexing.

Interesting facts

• Io is constantly squeezed by Jupiter’s gravity and nearby moons.
• Its volcanoes can send plumes high above the surface.
• Its colours come from sulfur and volcanic material.
• Io has few impact craters because its surface is constantly renewed.

Why this world matters

Europa is one of the most important places to study possible life beyond Earth.

Interesting facts

• Europa’s surface has long dark lines called lineae.
• Its surface is smooth compared with many other moons.
• A hidden ocean may contain more water than Earth’s oceans.
• Future missions aim to study whether Europa could support life.

Why this world matters

Ganymede is a moon that behaves like a complex world, with an icy surface, possible ocean and its own magnetic field.

Interesting facts

• Ganymede is larger than Mercury.
• It is the only moon known to have its own magnetic field.
• Its surface has dark ancient regions and bright grooved terrain.
• It is one of Jupiter’s four Galilean moons.

Why this world matters

Callisto is like a preserved record of early Solar System impacts.

Interesting facts

• Callisto is covered with impact craters.
• It is the outermost of Jupiter’s four Galilean moons.
• Its surface has changed less than Io or Europa.
• Some evidence suggests it may have a subsurface ocean.

Why this world matters

Titan has weather, clouds and surface liquids, but the liquid is methane and ethane instead of water.

Interesting facts

• Titan is larger than Mercury.
• It has lakes and seas of liquid methane and ethane.
• The Huygens probe landed on Titan in 2005.
• Titan has a thick orange haze that hides much of its surface.