Jupiter

Jupiter is the largest planet in the solar system - it's so big you could fit over 1,300 Earths inside it!

It's also the fastest rotating planet too, with 1 day only lasting 10 hours - but a year on Jupiter lasts for 12 Earth years.

Jupiter doesn't have a solid surface and is made up of gas, giving it the name 'gas giant'.

It has winds that can travel up to 400mph that swirl around the planet giving it bands and stripes.

These coloured bands are called zones and belts. Each one has a slightly different temperature and holds different chemicals to make them different colours.

Its most famous feature is its 'Red Spot', which is a storm that's so big it is visible from Earth. It's been raging for 300 years!

Jupiter is the planet that has the most moons in the solar system. It has 4 main moons that were discovered by a famous astronomer called Galileo Galilei in 1610, but there are now thought to be up to 64 moons orbiting Jupiter.

Its biggest moon's are called Ganymede and Titan, the largest moon's in the solar system - which is bigger than Mercury!

 

 

 

Mars

Mars is also known as the 'Red Planet' because it has lots of iron oxide on its surface giving it that rusty red colour.

It is the second-smallest planet in the system and fourth in line from the Sun meaning it can get pretty cold there.

Same as the Earth, it has a North and a South pole which are covered in ice, and reaching temperatures as low as -140°C.

20°C is the highest temperature on Mars, similar to a sunny day back here on Earth.

A day on Mars is slightly longer than here at 25 hours, but a Mars year is almost twice as long as an Earth year, taking 687 days to orbit the sun.

Mars also has the highest mountain in the solar system, called Olympus Mons, which measures around 15 miles high. That's three times taller than Mount Everest!

Mars is also known as the 'Red Planet' because of its colour.

Earth

Earth is our home planet and the only one known to support life. It is the fifth-largest planet and is orbited by one moon.

Our planet is the only one in the solar system to have water in its liquid form, which allows it to support life.

71% of Earth's surface is covered in water and the oceans help to keep the temperature cool enough for life to survive.

It takes 24 hours for the Earth to rotate once - a day - and it takes 365 days for the Earth to orbit the Sun - a year.

The surface of our planet is very young because it is always changing. The surface is made up of different sections called tectonic plates which move over time, re-shaping the Earth's surface.

Even though the Earth is over 4 billion years old, it is expected to support life for another 500 million years.

Venus

Venus is the brightest object in our solar system after the Sun and our Moon which means on a clear night you might be able to see it without using a telescope.

Because of this, people have known about its existence since prehistoric times and the first probe to visit it was in 1961.

Venus is sometimes called the 'Twin Planet' because it is similar to Earth. It's only slightly smaller than Earth and has an atmosphere complete with clouds.

These clouds are a bit more deadly than ours because they are made of sulphuric acid which is poisonous to us.

Acid clouds, mixed with an atmosphere of carbon dioxide, make Venus the hottest planet in the solar system reaching 482°C - that's almost 7 times higher than the hottest temperature ever recorded on Earth!

Venus also has the slowest rotation in the solar system meaning 1 day on Venus is the same as 243 days on Earth.

But for Venus to orbit the Sun takes just 224 Earth days, which means that a year on Venus is shorter than a day!

 

Venus has a deadly atmosphere of carbon dioxide making it an orange colour.

 

Mercury

Mercury is the closest planet to the Sun but surprisingly, not the hottest. It doesn't have an atmosphere so any heat the planet gets from the Sun quickly escapes back into space.

Temperatures can still get as high as 427°C which is 61 times hotter than the average temperature on Earth!

But because there is nothing to hold in the heat, Mercury can also reach temperatures as low as -173°C, almost twice as cold as the lowest temperature ever recorded on Earth.

No atmosphere also means the planet doesn't have a sky! If you could visit Mercury, you would be able to see stars at daytime and the sun would look twice as big.

Because Mercury is the closest planet to the sun, it has a very quick orbit. This means it only takes 88 Earth days to go round the sun which gives Mercury an 88-day year.

But it rotates quite slowly and means that a day on Mercury lasts for 59 Earth days.

The first probe to reach Mercury was in 1974 and it mapped out the surface to find it was really similar to our moon with lots of craters.

 

Mercury is the smallest planet with a surface similar to our moon.

 

The Sun

The Sun is at the centre of the Solar System, and its gravity holds all the planets in place.

The Sun is the biggest object in the Solar System and makes up 99% of its mass. Its diameter is around 109 times bigger than Earth, but you could fit over A MILLION Earths inside the Sun.

Astronomers think that the Sun (and the planets) formed from the solar nebula about 4.59 billion years ago, so it's pretty old!

Its temperature is 5,500 degrees Celsius on the surface and a whopping 15.6 million degrees Celsius at the core.

The temperature of the sun isn't the same all over; in some places 'sun spots' occur where it isn't as hot as elsewhere.

It's made almost entirely of hydrogen, with a little helium and a few heavier gases including oxygen - and there's even some iron in there too.

Light from the Sun reaches the Earth in just 8 minutes!

 

Remember - don't look directly into the sun, it could damage your eyes.

 

Nasa looking for volunteers to stay in bed - for ten weeks

You could say it's literally a dream job: getting paid to stay in bed.

American space agency Nasa is advertising for people to do just that.

They need volunteers who are willing to stay in bed, read a book or watch TV. The catch? They have to stay in bed for 70 days without getting up at all.

Nasa scientists need to study the effects of weightlessness on the human body and they felt one of the easiest ways to do this was to get people to put their feet up.

In Nasa's Bed Rest Project, volunteers will be placed in tilted beds so their feet are slightly higher than their body. They'll then stay that way - whether going to the toilet or showering, or eating.

After ten weeks they'll be asked to do a number of exercises to see how the lack of exercise has affected them.

Lying down for such long periods of time can cause loss in muscle mass and bone density.

 

But the Nasa team need very healthy people to take part: they said the volunteers should be as fit and capable as a real astronaut.