Back to Earth 1 Stargazing Live

Hello and welcome back to Jodrell Bank for Back To Earth, where we try

to answer as many of your questions as possible, questions from the show

we've just done. There were many questions raised. Joining me we have

Professor Brian Cox an the head of Europe's space weather forecasting,

Richard Horne, solar researcher, Lucie Green, the sky at night's

Chris Lintott, and Boulder Colorado 2010 Michael Jackson Costume Contest

winner, we have this winner from your Facebook pace, Carolyn Porco.

Congratulations. We talk you us up on one side of the show and bring

you down in the next. Did you have to dance as well? I did. These are

the Aurora cocktails. The colour may dissipate slightly because they're

under a UV lamp at the moment which is catching the blue in these. The

blue in the quinine in the tonic water. Getting a drink on this show

is becoming increasingly tenuous. Any justification. However, you

should try the planetary chocolates. You're happy with that. I think you

should take Saturn, if you can find it. I'm taking this one. Grab,

please take one. This isn't going to explode is it? Take and then I will

explain. I'm taking neptune. Still time for you to send in your

questions on anything we've talked about on Stargazing Live. Or use #Q

Stargazing. Are you finding it difficult to get chocolates? I've

just eaten the earth. ? Vment We've had many in, by the way. Quickly, we

haven't spoken to either of you, did you enjoy the sights of the Aurora

by the way? They were fabulous. It's exactly the sort of thing we've seen

in northern Scandinavia before, the beautiful seeing clouds like

curtains waving in the night sky, beautiful. It's impressive to see it

in real time. Norm lip we see movies of it sped up. But even in real time

it has that beautiful motion. We will pick what we left talking on,

we give you drink and food and get you to answer questions. With the

particularly striking image, obviously an artist's rendition of

an astronaut staring at a geyser. That means something else, geezer.

Do you enjoy staring at geezers? You do whatever you want, you're on

holiday, you're a long way from home. Would it be possible to

approach that closely in terms of it? If you were standing there and

looking, you had the sun at your back, you wouldn't even know they

were there. They're very tenuous. You don't see them until you're

looking in the direction of the sun, which is a geometry which highlights

small particles. That's why you see them in our images. They are almost

powder-sized particles. They're forming one of the rings, aren't

they, the E ring? Yeah, but that's very tenuous. Probably if you were

there, you'd barely see it. How do you set the exposure? You think it's

easy down here on earth with a camera. How difficult is it to get

these images? That is a complex answer. We had been to the Saturn

system with Voyager that. Was really a reconnaissance mission. It showed

us about how bright things were and when you, you know, you can't figure

out how long your exposure has to be until you know how much sunlight is

hitting the camera. Then you can determine the exlozure time. --

exposure time. Over time, as we have orbited Saturn over and over again,

our knowledge of just exactly how inherently bright everything is has

improved vastly. We know how much sun is getting to the Saturn system

to begin with. We know how much is reflected back into the camera.

There's a question here, how much longer is Casini expected to

operation before its plutonium runs out? You're constantly correcting

its path, because you're trying to focus on different things at

different times. That's true. But the plutonium we don't correct the

orbit using the plutonium. The plutonium supplies reck trace it I

to operate the computers an so on. We use Titan as a gravity body. We

go by Titan so many times. With ego by to study, but we go by if we want

to crank up the inclination to look at the poles of the planet and down

on the rings or we want to bring it into the equator plane to visit the

moons. We want to crank around the side lines. We use Titan for that.

We have a question from Lisa, aged eight. Why is Saturn made of gas?

That's a complicated question. But I can make it simple by reversing the

question and saying why don't the terrestrial planets have gas. You

want me to ask Lisa, aged eight... LAUGHTER

You don't need to do that because we're clever enough to figure out

how you to spin this. I learned that at NASA, how to spin. You just know

that the planets got a lot hotter. It was hotter there. The gas gets

warmer, warmer gas, the collisions are more vigorous and so on. The

small inner planets weren't large enough to hold onto this very

kinetic gas. But the outer planets, because everything was colder there

were. They were able to. This made perfect sense until we started

looking at other solar systems. When we find planets around other stars,

we find all sorts of things, mixed up solar systems with planets like

Jupiter and Saturn close to their parent stars. We end up explaining

that they formed further out and had to migrate in. Other solar systems

seem to have had an exotic path. Those big gassious planets are

closer to the star. That's true. But there's still a population we didn't

expect. When people started hunting for planets around stars, they got

lucky. They weren't expecting the hot Jupiters. I wouldn't be

surprised if the atmospheres there have limited lifetimes. This idea of

migration is interesting. You threw it away there, the fact that planets

move, they did it in the solar system most likely. Planets might

have swapped places. One of the best things we have discovered in the

ring arena in Saturns's rings is we have found moonlets embedded in the

rings. Somewhere between the largest ring particle size and the smallest,

you would call a moon. Called shepherd moons? No, They're bona

fide moons. They're 100 kilometres across. These things are only a

kilometre across or maybe half. That's not what you're talking

about. No That's not what I'm talking about. That's a shepherd

moon. These moonlets create these wakes that we call propel afeatures.

We watch them not only move around like a normal moon, but they drift

and they drift because they're interacting with the material. This

is giving insight into how planetary migration formed. It formed when

there was material around and there was exchange of momentum. Are the

discs increasing or decreasing, clumping, not clumping? Saturn's

rings are so close to Saturn that you can consider them like a

miniature solar I it emin an arrested state of development. --

system, in an arrested state of development. So they're trapped? And

also the tidal forces from Saturn prevent things from coagulating.

That's the beauty of it, it allows us to see processes that happened

long ago that are gone. Now, we are going to have a question, if you

didn't get your fill of Doctor Who over the Christmas, here is a treat.

If you did, humour us for this bit. It's the return of the most

intelligent robot dog with more space questions.

Greetings master Dara. Commander Hadfield famously created his own

version of a hit record in space. But Russian cosmonaut Mikhail Tyurin

has a space record of a different kind. What sporting feat did he

achieve on the International Space Station in 2006? What was that

sporting feat? Send us your answers in the next five minutes, using #K9

or e-mail us. Is that Twitter? Yes, Twitter. We'll read the best out

later when confer9 will be back to tell -- K 9 will be back to tell

all. We discussed the Carrington event. The Carrington flare. As

we're fond of calling it, the 70s detective Carrington flare. How do

we measure this change? So this is 1859. This is the first time that we

had a major event from the sun have a major impact on the earth. Really

good question. What are the consequences here on earth? How do

scientists measure it? At that time they were developing instruments to

measure changes in the earth's magnetic field. What the sun did was

produce activity that we'll come to, but the scientists measure the

changes in the earth's magnetic field. Here's a piece of kit to

demonstrate it. You have a magnet suspended in the jar. That aligns

itself with the earth's magnetic field. Let's imagine the sun has

done something and it's shaken up the earth's magnetic field, it's

changed it. I will represent that by bringing in this magnet. You can see

the alignment of this magnet creating a spot on the screen. If I

bring this magnet in, it starts to deflect it. That spot goes. I can

take it in and out, that's what the scientists saw. They saw something

happen to the earth's magnetic field that they hadn't seen before in this

strong a way and that's when they realised something big was was

happening. Not been taking these readings for very long. No, in the

Victorian era, early decades of the 18 hundreds, that's when the

sensitive magnetic detectors were being created. Early 18 hundreds or

there abouts. Still quite dramatic. We actually have it here. Have you

ever seen it before? I haven't. I have been waiting for a long time.

These are from the... British geological survey. These are the

actual, no we don't have a control view. We had the spot that moved

when I brought the magnet being here. You have a trace being made.

It gets distorted as a the earth's magnetic field. How quick was that?

This scale runs over one day. This is quite a big dip here, but very

short. This is over half an hour or so. About ten minutes. That magnet

moved quickly and came back again. That happened at 11. 18am, but

what's really key, that's the flare. Then what happened 17-and-a-half

hours later? If you measure from here going off the page andion to

the next page, something like 17-and-a-half hours later we see

this huge deviation in the earth's magnet sieve -- magnetic scale. It

goes off scale. That 17-and-a-half hours is the transit time for

material coming off the sun to actual reach the earth and actually

trigger a large magnetic storm. It's one of the fastest times, 17 hours,

I think the fastest actually... Maybe 16 hours. This one would have

been travelling 2300 kilometres a second. The energy of the particles

essentially. This is a very high energy particle. They have a high

speed coming towards us, yes. But actually, we get even higher energy

particles that this inside the earth's magnetic field. We come to

that in a moment. Can you give us a sense of what that would do, if that

magnitude hit us today. If a Carrington event occurred tomorrow,

it's a very big issue. We know back in, for example, you mentioned

yourself, back in 1989, we had a power outage in Quebec earlier, so

that was a storm that was a big storm, nothing like as big as the

Carrington event. Now we think we may have transformers on the power

grid, actually may be damaged. We may have six to 12 transformers in

the UK, lets let alone what would -- let alone what would happen in other

countries. Satellites would be affected by a large magnetic storm,

something like the Carrington storm. We would have satellites going on.

In 2003 there was a large magnetic storm. 47 satellites malfunctioned

during the storm. We have over a thousand satellites now. We have a

question here, could a solar storm be a threat to the International

Space Station? The energetic particles are a threat to human

health. Whether you're in an aircraft, or that high up on the

International Space Station, if you have accelerated particles because

of energy from the sup, you have to protect yourself. There is a shelter

on the Space Station. The astronauts have to go into the shelter. Cancer

damage or the physical damage to them? Because of the possible

increased risk of cancer, same happens on aircraft. You get an

additional radiation dose to aircrew on polar routes. When you have your

astronauts in, ask if they see thousands of -- flashes of lights in

their eyes because of the particles coming through their body. That's

incredible. Can we build an early warning system? I think we can build

one. What we need to know is information about the mass ejection

that comes our way and what is the magnetic field. You want our

satellites far away from the Earth but they need to measure the mass

ejection before it gets to us. At the moment we only have a 40 minute

warning. I run an international project called SPACECAST and we try

and forecast at this. We try to protect satellites, and we take

measurements from between the sun and the Earth. It is where the

gravitational pull of the sun balances the Earth. That gives us a

40 minute warning. The crucial measurement we make is the direction

of the interplanetary field. It is always changing, but when it is

facing southwards, it can connect to the Earth's field and you get a

tremendous transfer of energy and that gets redistributed back and

into the charged particles. There is the son's magnetic field

transferring energy. Yes, it is essential because we could have a

mass ejection coming towards the Earth but if the magnetic field is

facing northwards there will not be much impact. If it is facing

southwards, it would be huge. We are threatening an apocalypse! We need

to understand it in order to survive! What sporting feat did

Mikhail Tyurin set in space? You have sent the answers in. Juggling?

No! Tiddlywinks? Sarah says is it a forward roll? I like that! Any

guesses? Gymnastics, I think! Weightlifting? No! Baseball? The

first person to hit a golf ball? That would be a Scot in one of the

Apollo missions. Let's have a look at what canines said. Mikhail Tyurin

used the International Space Station as a driving range to hit the

longest golf shot in history. With a six iron he hit a golf ball 1

million miles before it burned up in the Earth's atmosphere two days

later. In the intergalactic rules of golf is a 2-stroke penalty! Until

tomorrow, farewell! Yes, it was striking a golf ball. We have some

footage here of the record-breaking shot. It may be difficult to see. In

fact, it may be impossible! There it is. We can show you it in slow

motion. He struck it. I do not think that is entirely responsible! Has he

not seen the film Gravity! ? We have had a lot to complain about in terms

of weather here which probably Sargent to ask whether it rains on

other planets. What substance is the rain made of? You were talking about

Titan and on Titan it rains methane. It is orange rain. I do not think it

is orange. Methane is very clear. Snow and rivers and lakes are on the

surface of Titan. Methane drops will be bigger than raindrop. You have to

imagine Christmas baubles. They are like dinosaur raindrop. We also have

diamonds. I am told they are representing diamonds! That would be

Saturn. I have never heard of that. I you sure it is not a star? There

is a hot Jupiter where they detect the diamond. I know they have

detected particles of carbon. I know about that. I do not know about

Saturn. Hot Jupiter? We have normal Jupiter and other stars have hot

Jupiter. It was a Neptune sized thing. I am being careful with this

because it is sulphuric acid. I will not go anywhere near this. Where is

this question my Venus. I do not think it rains but there are tiny

droplets in the cloud. Venus is fascinating because, before the

space programme, it was thought it could be a tropical world. I think

Sir Patrick Moore wrote that there could be tropical rainforests on

Venus. They did think there was something of that ilk on Titan as

well. There was a brief period on Venus where they thought it was

carbonated water on the surface as well stop a cocktail of ingredients!

Sadly, there is this rather hot, unpleasant volcanic world. I think

we get the gist of this. I thought you were going to dissolve the

glasses in the sulphuric acid! Why are you not wearing gloves? Put on

the ridiculous gloves! This is health and safety! Right, I am ready

now. I will continue to do the entire show live. I make these

glasses look small! Questions on Saturn. How do you get your pictures

Back to Earth from Cassini? It is not little green men. The pictures

are digital information which are encoded on the telemetry stream. How

large are the files? A typical image which is compressed and B four

megabytes. Sorry, I mean megabits. I think I have got that right. Not

enormous. This mission was designed in the 1980s so by today's

standards, they are tiny. You compare that with a spacecraft that

has just launched and it has a 1 billion pixel camera in it. It is

astronomical! Cassini is an old mission already. Clear skies have

been hard to come by recently but when the clouds part here is what

Mark Thompson recommends you look at the night. The winter night sky is

signposted why Exeter and of stars. Jupiter is a good starting point.

Look to the South East and you will see a bright object 45 degrees above

the horizon. Directly to the left of Jupiter is the brightest star in the

Gemini consolation. To find the next start, go back to Jupiter and look

directly upwards. This is the third brightest star in the northern sky.

Now find the lowest sky in the Hexagon and look to the right. This

is one of the horns of tourists. The two horns lead back to a V shaped

cluster of stars. The next star in the Hexagon is in the constellation

of Orion. Follow the line down from that and you will see Orion 's belt.

Burning white hot and over 130,000 times brighter than the sun. There

is another consolation of Canada's major. -- Canis Major. The final

start in the Winter Hexagon is the binary star. If you follow a line

from serious you will find it passes through the small consolation of

Canis Minor. The Winter Hexagon is visible from September to April, and

from January it can be seen after sunset. Do not worry if you do not

get that because you can find the details on the website. You have

been sending in your stargazing photos from across the UK. I really

like this first image. He took it with a simple camera and you can see

the colour of the stars in Orion. It is wonderful shot. This is the

Winter Hexagon as experienced by Gordon. You can see the beautiful

lighthouse. Even light pollution can be beautiful if used correctly. I

wanted to show this. I like this. This was taken on Saturday on top of

the town hall in Newcastle. David does not say what he was doing on

top of the town hall? ! There is a sunspot circled here and that is the

sunspot we were talking about. We care about sunspot groups because

they are exciting for people like Lucie but because they do things

like this. This was taken on January the 1st and was uploaded from

Scandinavia. The username is mamma Mia! That is why I am guessing it is

from Sweden. The Aurora, people were seeing it in Scotland, in Donegal,

in the Hebrides. We would be interested in seeing photos from the

UK. What with the aim you wanted when you set the challenge? We

thought we could do something with half a million clips. The more we

get, the more active we are! Two quick questions. How fast does the

solar wind go? Voyager one has just passed 15 billion kilometres and it

took 30 years to get there. That is where the solar wind ends. That is

where we regard the end of the solar system. A question from Hannah.

Could there be life on Titan question my personally, I do not

think so. It is so cold and there is no liquid water. There is no life

that we would even recognise. Titan is still a fascinating targets

because it is covered in liquid organic and there is no place else

in the solar system where you have seized of liquid organics so it is

like a laboratory begging for study. You cannot study natural

organics here on the Earth because they are gone. It is the most

accessible in the solar system. You very much indeed. Thank you to all

of our guests. Carolyn Porco, Lucie Green, and Richard Cox -- Brian Cox.

We have two former astronauts on tomorrow, Walter Cunningham and

Chris Hadfield. Get your westerns in and we will ask as many as we can.

Thank you for joining us, see you tomorrow.