Space Voyage Liz Puchnarewicz Mullard Space Science Laboratory This talk was written for 6 to 7 year olds … taking them on a tour of the planets in our Solar System, and looking at the Earth-Moon system. Liz Puchnarewicz Mullard Space Science Laboratory University College London www.mssl.ucl.ac.uk

Blast off from the Earth 4 3 2 1 5 6 10 7 9 8 To begin our tour, we have to leave our planet, the Earth first! We’re going to lift off from the European Space Agency’s spaceport in Kourou. Kourou is in French Guiana on the north coast of South America, and is home to dense jungle, swamp, local Indian tribes and the odd gold miner. It is France’s former penal colony. We’re going to hitch a ride on an Ariane V rocket, just like the one that launched the XMM Newton observatory in December 1999. It blasts off from the Earth and heads off towards the Sun where we start our tour. St. Cuthbert Mayne Cranleigh

First stop – the Sun Enormous hot ball of gas. 109 times bigger than the Earth. Only going to burn for another billion years! The Sun gets very hot, reaching millions of degrees! It gets so hot that X-rays are given off and this picture is what the Sun would look like if we had Superman’s X-ray eyes. It looks as though it’s bubbling and boiling like a great hot cauldron… and occasionally it throws off very hot gases like water from a hose, into outer space. You can see some of these gases coming off the top of the Sun in this picture. Some of the hot gases reach our own Earth and can break satellites, they can be dangerous to aeroplanes … they can even break computers if we’re very unlucky! The Sun is our very own star and its really just a big ball of hot, bubbling gas. You can fit 2000 Earths into the Sun and it’s been burning for about one billion years. It’s only got another billion years to go though! Then it will start to get colder, turn red and grow bigger and bigger, eating up Mercury, Venus and the Earth. Then it will shrink back down again, getting smaller and smaller until it turns into a white dwarf star. It will be very faint then and even if it hadn’t eaten the Earth, it wouldn’t be hot enough to keep us warm anymore. This is an X-ray of the Sun!!

Follow the Sun in the Sky So let’s follow the Sun as it wanders across the sky. When it first comes up, the Sun looks like a big, red fireball. It looks red because there’s lots of dust in the air along the ground. As it climbs up, the Sun turns orange, then yellow. And it looks smaller. The colour of the Sun tells us exactly how hot it is. The Sun looks yellow because our eyes tell our brain that anything that is as hot as the Sun is yellow. If it was a bit colder, it would look red. If it was a bit hotter, it would look blue. The Sun may look smaller when it’s high in the sky, but it’s just an optical illusion! It’s always the same size!

Follow the Sun in the Sky South No matter where you are in the world, the Sun always rises in the East and sets in the West. In the northern hemisphere, the Sun is towards the South in the middle of the day.. In the southern hemisphere, it’s in the North. East West

The Giant Sundial So let’s follow the Sun as it wanders across the sky. When it first comes up, the Sun looks like a big, red fireball. It looks red because there’s lots of dust in the air along the ground. As it climbs up, the Sun turns orange, then yellow. And it looks smaller. The colour of the Sun tells us exactly how hot it is. The Sun looks yellow because our eyes tell our brain that anything that is as hot as the Sun is yellow. If it was a bit colder, it would look red. If it was a bit hotter, it would look blue. The Sun may look smaller when it’s high in the sky, but it’s just an optical illusion! It’s always the same size!

So what does this mean? The Earth spins around once a day… Cranleigh Well, it doesn’t mean that the Sun goes around the Earth! Although it’s easy to see how astronomers thought that until a few hundred years ago. It means that the Sun stays still, but the Earth spins around once a day. At 12 noon, the Sun is directly overhead. At 6o’clock in the evening, the night-time is coming and the Sun is seen setting in the West. At midnight, it is dark all around and we are surrounded by bright, twinkling stars. The Sun rises at about 6o’clock in the morning, in the East… and by 12 noon the Sun is overhead again. The Earth spins around once a day…

Now – on to Mercury 1 day = 59 Earth days Days very hot – Now we’ve had a good look at the Sun (and we’re getting a little warm…) let’s move onto Mercury. Does it remind of you of anything closer to home? Mercury looks a lot like our Moon… dry, dusty and with loads of craters. And the days are very long on Mercury… an Earth day is only 24 hours, but on Mercury it takes 59 Earth days from one dawn to the next! That would mean that your school day would be almost 15 days long! And because the days are so long, and because it’s so close to the Sun, it gets very hot in the day, reaching 430 degrees Celcius, and very cold in the night, falling to –170 degrees Celcius. Days very hot – Nights very cold!!!

And the next planet is… Venus!!! 1 day = 243 Earth days 1 year = 225 Earth days!!!

Wave to your Mum – the Earth is next

Did you know that the Earth and Moon are a double planet?

Earth goes around the Sun – Moon goes around the Earth

Earth goes around the Sun – Moon goes around the Earth

These are the phases of the Moon

It’s Mars! Look out for little green men!!! 1 day = 1 Earth day 1 year = 687 Earth days

Jupiter The nearest and biggest of the giants. Great Red Spot Jupiter The nearest and biggest of the giants.

Which is the flattest planet? …Saturn And how do we know? …Because someone ‘saturn’ it!!!

This is Uranus It takes 84 years to go around the Sun

The next giant is Neptune (usually) Great Dark Spot Scooter

And last of all - Pluto … and his friend, Charon. It’s another double planet!

Watch the planets going in circles!

Back to Earth

Journey over!