06/08/2014 Newsround

Hi, guys.

I'm Ayshah and you are live with Newsround with the kids

meeting the Prime Minister coming up.

Plus the spacecraft on a mission to discover how life on Earth began.

And we want you to tell us where your pet goes on holiday.

But first to the six young musicians who have just completed the

performance of their lives. The stars of CBBC show The Big

Performance have been working hard to come up with a song to sing at a

special event in Belgium to mark 100 years since the start of World War

I. Ricky went along to see how they got on.

Guys, you're performing in about an hour's time.

How are you feeling?

I am extremely nervous, but I think I am more excited

because it is such a big occasion.

I am just got to try and channel all the nerves into

energy so that I am really excited.

It is fabulous, it is really good to be here, finally, because you

understand what the song needs to be like when it is performed.

It has to be relaxed, it has to be beautiful and thoughtful.

Because these are war graves.

It is not a pop song.

Before we go and perform, somebody very important would

like to meet us.

Prime Minister David Cameron.

No!

No way.

Where are you from?

My name is Sam and I am from Exeter.

To know that people like David Cameron are rooting for us and

they want us to succeed is amazing.

David Cameron was asking us stuff like where we were from, who

wrote the song, stuff like that.

I think we were all really nervous answering him.

So the kids from the Big Performance have now met the Prime Minister,

they have done the rehearsal.

In less than an hour they will be singing right here.

I bet they are feeling very, very nervous.

I am just doing this to keep the nerves away.

I am just really nervous.

I cannot believe my songs is going to be heard by millions of people.

Enjoy it.

Shall we go?

Yes.

# Stand up.

# Be proud.

# They are all our heroes.

# Fight for peace.

# We walk ahead as one.

And The Big Performance is on every day this week and you can see that

episode from Belgium on Friday. And there is loads more about World War

I on the Newsround website too.

In other news, China says a rare gas on the moon could help power earth

for the next 10,000 years. The Chinese became the first country in

40 years to land a spacecraft on the moon's surface last year. And now

the scientists behind the project say mining for a special lunar gas

called Helium 3 could help provide a new kind of energy. Scientists here

say it could be possible.

And sticking with space, a probe that has been chasing

a comet across the solar system for ten years will finally reach

its orbit this morning.

The Rosetta spacecraft could become the first man-made object

in history to travel around an icy, 10,000-mile an hour comet.

And scientists hope it could help unlock some of the mysteries

of life.

Very soon the Rosetta spacecraft will begin to orbit this comet

and then spend the next few months analysing what it is made from.

Its mission is to find out whether comets kickstarted life

on planet Earth.

Comets scattered across the early Earth 4.5 billion years ago bringing

with them water and possibly some of the ingredients for life.

Scientists believe those ingredients mixed to create the chemicals

from which life may have emerged.

The biggest question that we are trying to get an answer to is

where did life on Earth come from?

Did it start, how did life get going?

Was it the building blocks of life that were brought to us from comets?

Rosetta will spend the next few months taking measurements

and pictures of the comet.

It is up close and personal.

We will be able to understand everything that there is to

understand about the comet, about the chemical composition,

about whether the ice on the comet was indeed the source

of the oceans on planet Earth.

In November, scientists plan to land a probe to see what it is made

of and find out whether comets hold the key to how life began on Earth.

And finally, you are on your summer break from school, you might be off

Earlier this week we told you that research suggested more

of us are taking our pooches, cats and other animals away with us.

So we want you to get in touch and tell us if your pet's going

on holiday and where to.

Head to the Newsround website to find out how to get involved.

That's all from me, Newsround's back right here this afternoon at

4:20.