Young Astronomers

7 to 11 Years Old


There are 8 planets in our solar system, the 4 planets closest to the Sun are called the inner planets and these are rocky (Mercury, Venus, Earth, and Mars).  The 4 planets furthest away from the Sun are called outer planets and these are made of gas (Jupiter, Saturn, Uranus and Neptune).  Gas planets do not have a solid surface so we cannot land on them.

All planets are round in shape, and all orbit (goes around) a star.  Our nearest star is the Sun.

Venus and Uranus both rotate clockwise, all the other planets rotate the other way (counter-clockwise).



Mercury is the first and smallest planet in our solar system, and is the closest one to the Sun.  It has lots of craters and is slightly bigger than our Moon.

If you went to Mercury by spaceship, it would take 5 months to get there.

The planet gets very hot during the day and very cold at night.  The average temperature ranges from -180°C to 430°C (-290°F to 800°F).

One day on Mercury is the same as 59 days on Earth, and one year is the same as 88 Earth days.  This means it takes 88 Earth days for Mercury to go around (orbit) the Sun.

Mercury does not have any moons.



Venus is the second planet from the Sun and it would take a spaceship 4 months to get there.  But if you tried to walk on the planet’s surface you would die from acid burns, roasting, crushing and suffocation.  Not a nice place to go to.

One day on Venus is the same as 243 Earth days, and one year is equal to 224 Earth days.  A day on Venus is longer than its year.

The average temperature on Venus is 460°C (865°F), making it the hottest planet in the solar system.

It is covered by thick clouds and it smells like rotten eggs, and when the Sun shines on the clouds, it makes Venus look very bright.

Venus has lots of volcanoes and its surface is covered in lava.

When Venus is in the sky in the morning, it is known as the Morning Star, and when it is in the sky in the evening, it is known as the Evening Star.

Venus does not have any moons.



Earth is the fifth largest planet in the solar system and the third from the Sun, and is the only planet covered in water, and the only one with plant and animal life on it.

An Earth day is 23 hours and 56 minutes long and it takes 365.25 days (1 year) to go around the Sun.

The average temperature on Earth is 15°C.

Our planet is spinning at 1000 miles an hour.

The Earth is tilted which is why we have seasons, so when the Earth is tilted towards the Sun it is summer, and when it is tilted away from the Sun it is winter.

Earth’s gravity stops you from floating in the air.

We have one moon.



Mars is the fourth planet from the Sun and it would take 8 months to get there by spaceship.

A day on Mars is the same as 24 days 37 minutes on Earth, and 1 year is the same as 687 Earth days.

The temperature on Mars ranges from -125°C to 25°C (-195°F to 77°F).

Mars looks red because it is covered in rocks that have a lot of iron which has rusted.

Mars has two moons called Phobos and Deimos.  These moons look like potatoes.

Mars has the largest volcano in the solar system.  It is called Olympus Mons and it is so big that it would cover most of England.



Jupiter is the fifth planet from the Sun and is known as a gas giant.  All the other planets in the solar system could fit inside Jupiter.

If we flew to Jupiter, it would take a spaceship would take 13 months to get there, but we would not be able to land on the planet as it is made of gas and does not have a solid surface, and its storms would soon destroy the spaceship.

One day on Jupiter is the same as 9 hours and 55 minutes on Earth, and a year is equal to 11.86 Earth years.

Jupiter is cold on the surface with an average temperature of -143°C (-234°F) although it is hot near the centre of the planet.

The planet has a huge storm which has been raging for hundreds of years; this is known as the Great Red Spot.  Earth could fit inside the Great Red Spot.

There are bands of clouds called zones and belts with go around the planet.  The clouds that run around the middle of Jupiter move at more than 45,000 km/h (28,000 miles per hour).

Jupiter has 63 moons; the four largest ones are called Io, Europa, Ganymede and Callisto.



Saturn is the sixth planet from the Sun and is made of gas.

A day on Saturn is the same as 10 hours 39 minutes on Earth.

Saturn takes 29 Earth years to go around the Sun.

The average temperature on Saturn is -140°C.

A spaceship would take 4 years to get there.

Saturn has a ring system, and these rings are made from rocks and ice.  The rocks can be the size of a speck of dust or the size of mountains.

Saturn has 53 moons.  The biggest is called Titan which means giant.

Titan is bigger than the planet Mercury.



Uranus is the seventh planet from the Sun and it would take a spaceship 8 years to get there.

Uranus is a gas planet and spins in the opposite direction to Earth.

One day on Uranus is the same as 17 hours and 14 minutes on Earth.

It takes Uranus 84 Earth years to go around the Sun.

The average temperature on Uranus is -195°C.

Uranus is tipped on its side.  It is possible that something large hit Uranus and tipped it over.

Uranus is one of the coldest planets.

It has 13 rings, but it is very difficult to see them.

There are at least 27 moons, one of which is called Miranda which has canyons 12 times deeper than the Grand Canyon.



Neptune is a gas giant like Jupiter, and is the eight planet from the Sun.  It would take a spaceship about 12 years to get there.

One day on Neptune is the same as 16 hours 7 minutes on Earth.

Neptune takes 164.8 Earth years to go around the Sun.

The average temperature on Neptune is -200°C.

It takes Neptune 164 years to go around the Sun.

Neptune has the fastest wind speeds in the solar system, the winds blow at over 1000 miles an hour.

Neptune had a large storm called the Great Dark Spot, but it only lasted a few years before disappearing.

It also had a white cloud called Scooter that raced around the planet in 16.8 days.

Neptune has 13 moons, the largest is called Triton and this moon is one of the coldest places in the solar system.

Triton has volcanoes that blows dust and gas into the air, this freezes and falls like snow.