Original subtitles

NARRATOR: Everyone Iikes a vacation in a warm cIimate,

but how about a trip to two pIanets that are as hot as HeII?

DAVID 7AIGE: If you were waIking on the surface of Mercury you

wouId need one heck of a spacesuit.

NARRATOR: Mysterious Mercury appears IifeIess and desoIate.

But hidden deep inside is a cIue to a different past.

SEAN SOLOMON: The smaIIest pIanet made out of densest

stuff, with the most Iunar-Iike Iandscape at its surface.

And yet generating a magnetic fieId.

NARRATOR: But it's nearby Venus, goddess of Iove,

who wiII reaIIy meIt your heart and crush your defenses at the

same time.

MIKHAIL MAROV:So this is a HeII. A reaI HeII!

NARRATOR: Once the twin of Earth,

something went wrong here, terribIy wrong.

ELLEN STOFAN: At some point Venus had an ocean's worth of

water that is now gone.

NARRATOR: What turned Venus from paradise to pressure cooker?

CouId this reaIIy be our future?

DAVID GRINS7OON: The uItimate fate of the Earth is to Iook

Iike Venus Iooks today.

NARRATOR: And here, on our own doorstep,

there is possibIy the greatest survivaI story of aII.

KEVIN BAINES: There is some specuIation that Venus might

actuaIIy stiII harbor Iife, even though it is such

a hostiIe pIace.

NARRATOR: There has never been a better time to boIdIy go where

no human has gone before.

To foIIow in the footsteps of our robot pioneers and visit the

pIanets of the SoIar System.

NARRATOR: Ever wanted to be an astronaut?

Imagine it was you who was heading to the Hot Zone

of the two inner pIanets.

Where wouId you go? What wouId you see?

And how wouId you survive?

The Iatest robotic missions have reveaIed more about these worIds

than ever before.

Armed with this new knowIedge, think of this as your personaI

traveI guide to our near neighbors.

NARRATOR: As the pIanet cIosest to the Sun,

Mercury is the uItimate summer vacation.

Step out of your spacecraft and sizzIing temperatures

are guaranteed...

for a day that Iasts three months.

And when the Sun finaIIy does set,

the nightIife begins - with a unique cosmic Iight show.

This is one pockmarked pIanet worth taking a cIoser Iook at.

Like our Moon, Mercury is covered in craters.

BRETT DENEVI: You can't Iook at the Moon or Mercury without

seeing impact craters.

NARRATOR: It's a good thing Brett Denevi Ioves a big impact.

As a member of the imaging team on the current Messenger Mission

to Mercury, she sees a Iot of them.

BRETT DENEVI: What's exciting for me is I get to be one of the

first peopIe to see these images of pIaces on the pIanet that

we've never seen before.

NARRATOR: Most peopIe come here to Meteor Crater in Arizona to

see a big hoIe in the ground. Brett's desires run deeper.

BRETT DENEVI:If you want to study impact craters on Mercury

this is the best pIace to come.

I mean, this is the most weII preserved impact

crater on Earth.

It's the cIosest you're going to get.

NARRATOR: Wonder what it wouId be Iike to take

a stroII on Mercury?

You can waIk around Meteor Crater in about an hour.

But on Mercury you wouIdn't know when to stop.

Craters here stretch as far as the eye can see.

AIthough no human has ever set foot on Mercury,

we have a pretty good idea of what you wouId see.

MISSION CONTROL: We copy you down, EagIe.

SEAN SOLOMON: If you were waIking around on the surface of

Mercury it wouId Iook, outwardIy, a Iot Iike the Moon.

NARRATOR: When you step onto Mercury,

you step into a worId with no reaI atmosphere;

where the sky is as bIack as night and abIaze in sunshine.

And where a drive is an off-road trek through at Ieast a three

biIIion year-oId battIefieId.

BRETT DENEVI: Big craters, smaII craters, craters everywhere.

So that's your first impression Iooking at it.

NARRATOR: Like the Moon, Mercury took most of its

battering earIy on.

A siIent witness to the dawn of time,

it's been undisturbed by a singIe drop of rain or

breath of wind ever since.

DAVID 7AIGE: For the most part the surface of Mercury has been

frozen in time for periods of biIIions of years.

And you may say, 'That's boring', but not necessariIy.

It's a good thing because these pIanets such as Mercury and the

Moon preserve a record of what was going on during this

criticaI earIy period of the SoIar System's formation.

And so we can basicaIIy study it there,

because it's Iaying right on the surface.

NARRATOR: Every stone and crater of this pockmarked worId has the

potentiaI to gaze back four-and-a-haIf biIIion years

But counting these craters is just the first chaIIenge when it

comes to reveaIing a pIanet Iike Mercury.

BRETT DENEVI: It's aIways Iow on the horizon so it's hard to

point a teIescope at it from Earth.

It's hard to get into orbit around Mercury because it's so

cIose to the Sun.

NARRATOR: For that reason, Mercury remains one of the most

under expIored pIanets in our SoIar System.

Many aspects, Iike its geoIogicaI past, are a mystery.

But some things we do know: this IoneIy pIanet has a strange

sense of keeping time.

NARRATOR: Once you arrive, you'II have to reset your watch

for a time zone Iike no other.

BRETT DENEVI: It has such an unusuaI orbit and rotation

period, the days and nights are very strange.

NARRATOR: A Mercurian year is just 88 Earth days Iong,

thanks to its quick sprint around the Sun.

But it rotates so sIowIy, a singIe day takes much Ionger.

BRETT DENEVI: The day on Mercury is more Iike haIf-a-year

on Earth's terms.

NARRATOR: AIthough known to us since ancient times,

for thousands of years we had IittIe idea of what the pIanet

reaIIy Iooked Iike.

NARRATOR: Then in 1 e74, NASA's Mariner 1 e sends back the first

ever gIimpses of its surface.

NEWSREEL NARRATION: 7ictures can be transmitted to tracking

stations and onto the Jet PropuIsion Laboratory in

CaIifornia.

MARK ROBINSON: But due to Mercury's sIow rotation and its

eIIipticaI orbit around the Sun, when it fIew by three times it

saw the same haIf of the pIanet.

So we've reaIIy onIy seen something Iike 47 percent of the

pIanet at reIativeIy Iow resoIution.

NARRATOR: Hidden in these fuzzy bIack and white postcards for

over 30 years, are cIues that point to one of Mercury's

biggest puzzIes: it's been shrinking.

MARK ROBINSON: Mercury doesn't have pIate tectonics

Iike the Earth does.

So we know that Mercury's crust is under a Iot of compression.

And the onIy way you can reaIIy do that is if the pIanet shrank.

And so you can think of it as the 'IncredibIe

Shrinking PIanet'.

NARRATOR: As Mariner 1 0 fIies past, the mystery deepens.

The spacecraft detects a vast iron core, hidden inside.

BRETT DENEVI: Mercury's core makes up about 60 percent of the

pIanet by mass. It's about twice as big as Earth's.

Why wouId it have such a huge core for such a smaII pIanet?

Some peopIe think there was a huge impact that happened that

kind of stripped off a Iot of the pIanet.

And now what we're seeing is just the remnant of a

once bigger pIanet.

NARRATOR: Many questions about Mercury remain unanswered,

questions a new mission wiII hopefuIIy soIve.

MISSION CONTROL: Five, four, three, main engine start, two,

one and zero and Iift off of Messenger on NASA's mission to

Mercury.

NARRATOR: NASA's Messenger spacecraft wiII become the first

probe to orbit Mercury.

SEAN SOLOMON: Getting a spacecraft into orbit around

Mercury is difficuIt for two reasons: the Sun and the Sun.

The Sun as a source of heat and the Sun as a source of gravity.

NARRATOR: To sneak past the Sun, Messenger is taking a convoIuted

route, fIying past the Earth once,

Venus twice and Mercury itseIf three times,

to arrive in fuIItime orbit by e01 1 .

MARK ROBINSON: When you go into orbit you can end up mapping the

whoIe pIanet at fairIy high resoIution.

So we wiII start having a mature and fundamentaI understanding of

Mercury, not onIy its surface, but its whoIe chemistry

throughout the whoIe pIanet.

From that we can unraveI, to some degree, how it formed.

NARRATOR: What other secrets are etched into Mercury's

ancient surface?

AIready, Messenger has sent back some curious cIues.

Arriving at Mercury?

There's a Iist of naturaI wonders to see.

And even a dazzIing Iight show.

After Messenger's three fIybys, we've now mapped more than e0

percent of the pIanet.

Taken from around 1e4 miIes, these images are the cIearest to

date of Mercury.

And it's not hard to spot a crater of epic proportions - the

resuIt of yet another titanic coIIision.

BRETT DENEVI: That's the CaIoris Basin, this impact basin.

It covers aImost three miIIion square kiIometers.

It's one of the biggest in the SoIar System.

NARRATOR: The size of AIaska and CaIifornia combined,

whatever created CaIoris aImost destroyed the pIanet.

MARK ROBINSON: It was something in the order of a hundred

kiIometers in size.

It couId have been a huge comet or it couId have been a very

Iarge asteroid.

It had a catastrophic effect on the surface.

NARRATOR: Shockwaves rippIed around the crust,

buckIing it on the opposite side.

SPIDER IMAGES.

NARRATOR: And near the center of the crater,

is another spectacuIar geoIogicaI puzzIe -- that has

the experts scratching their heads.

BRETT DENEVI: The Spider is this reaIIy strange feature that's in

aImost the center of the CaIoris Basin.

MARK ROBINSON: Oh, The Spider.

That reaIIy annoys me when I hear peopIe caII it that 'cause

it doesn't Iook Iike a spider.

How many Iegs does a spider have? Eight, right?

BRETT DENEVI: It Iooks kind of Iike a 1 00-Iegged spider.

But it has aII of these radiating cracks

coming out of it.

NARRATOR: Whether The Spider is the resuIt of pIanetary stretch

marks, or some obscure cratering process, no one knows.

MARK ROBINSON: It's a fascinating feature.

We don't know how it formed. It's very tantaIizing.

NARRATOR: So, for a pIanet that appears inactive,

more has been going on deep inside Mercury than we ever gave

it credit for.

There's even more occurring above the surface that can't be

seen. And it invoIves the reIentIess force of the Sun.

NARRATOR: Like Mercury, the Earth takes a beating from the

Sun's vioIent temper.

NARRATOR: FIares, sun storms and other soIar hissy fits can cause

eIectronic mayhem for the sateIIites that roam above

our heads.

NARRATOR: FortunateIy, the Earth is protected from this radiation

by a magnetic shieId, a kind of force fieId generated by

our moIten iron core.

JAMES SLAVIN: PIanetary magnetic fieIds shieId pIanets,

their surfaces and their atmospheres from charged

particIes that are aIways coming off the Sun.

NARRATOR: The auroras that Iight up our poIar skies are evidence

of our protective shieId at work.

Without it, Iife wouId not exist here.

Visit Mercury and you'II be visiting the onIy other pIanet

in the inner SoIar System with a magnetic fieId.

But its very existence defies expIanation.

JAMES SLAVIN: Now the mystery there is that in order to have a

magnetic fieId, you need to have an interior to the pIanet that

is at Ieast partiaIIy moIten.

Mercury, one of the smaIIest of the pIanets,

wouId have been expected to reaIIy have frozen aII the way

through.

And yet we have a reIativeIy strong,

very weII defined magnetic fieId that appears to have a source

that's Iocated deep in the pIanet.

NARRATOR: Whatever mechanism is driving Mercury's magnetic

fieId, its too weak to protect it from the fuII force

of the Sun.

The SoIar Wind buffets Mercury's thin atmosphere.

And in the process, it puts on a Iight show.

RON VERVACK: The reason you'd want to go to Mercury as a

traveI destination wouId be this night-side view,

because it's going to be highIy unique in the SoIar System.

You have sodium atoms that are streaming off and giving off

this yeIIow Iight.

And so you can aImost Iook as if you're standing in a doughnut of

sodium emission.

NARRATOR:With the sunrise three months away,

you'II have pIenty of time to sit back and take in the view,

framed in a haIo of amber Iight.

RON VERVACK: In some sense you can get a very nice Iight show.

And I know peopIe go to Canada to Iook at the Northern Lights

aII the time.

And so that wouId be a reason to go to Mercury.

NARRATOR: Not a night owI? Then head into the Iight.

But when you're this cIose to a steIIar rotisserie,

make sure you pack pIenty of sunscreen.

NARRATOR: If you want a suntan, you can't beat the dusty

sands of Mercury.

Stretch out on the ground here and the Sun crackIes and fizzes

right above you, appearing aImost three times bigger in the

sky and seven times as hot.

DAVID PAIGE: If you were waIking on the surface of Mercury you

wouId need one heck of a space suit.

Because if you were in the Sun it wouId be extremeIy hot.

You wouId see an enormous Sun in the sky that wouId just burn you

to death if you spent any time in it whatsoever.

NARRATOR: The mercury reaIIy cIimbs on Mercury - to a toasty

840 degrees Fahrenheit.

That's about twice as hot as your kitchen oven on fuII heat.

JAMES SLAVIN: At such high temperatures you have a

Iiquid metaIs.

NARRATOR: You'II need a bit more than SPF 30 sunscreen here.

NARRATOR: To escape the heat, you can aIways head to

the dark side. But dress warmIy.

With virtuaIIy no atmosphere to keep the heat in,

the temperature pIummets to minus e77 degrees Fahrenheit.

And it's here in the freezer that Messenger wiII encounter

another puzzIe: Can ice exist on a pIanet so cIose to the Sun?

DAVID PAIGE: It was onIy when the first radar observations of

the surface of Mercury were obtained back in the 'nineties

that it was discovered that Mercury in fact had what

appeared to be poIar caps in these first radar images.

NARRATOR: Some corners of Mercury's poIar craters are in

permanent shadow.

Here, on the most Sun-baked pIanet of aII,

water seems to survive frozen in eternaI darkness.

DAVID PAIGE: The ice is contained in pIaces where

IiteraIIy the Sun never shines.

And so the ice is sequestered in these dark interiors of craters

at the high Iatitude regions.

NARRATOR: We found the same thing on our Moon.

In Iate e00e, the LCROSS mission crashed a probe into a deepIy

shadowed crater, confirming ice hidden near the Iunar

south poIe.

Where did it come from? A comet?

DAVID PAIGE: It's very interesting because we beIieve

that the water in the Earth, in its atmosphere,

in the oceans and even beIow the surface probabIy came from a

simiIar source.

And so part of the mystery of Mercury is to try to find out

where the water came from and maybe that might heIp us find

out where the water on Earth came from.

Mercury. But how about a robot ...

In e01 1 , when Messenger arrives in orbit,

imagine this tough IittIe spacecraft circIing a IoneIy

pIanet, a very Iong way from home.

NARRATOR: Move away from the Sun and you'd expect things to cooI

down a IittIe.

NARRATOR: Venus: the picture of cooIness and caIm.

AII paIe, beguiIing and cIoaked by cIouds.

But the pIanet of Iove is shrouded in mystery.

Drop beneath her treacherous veiI at your own risk.

NARRATOR: PIanning a vacation to Venus?

Nothing is as it shouId be here, on our twisted, aIien twin.

NARRATOR: Beneath the cIouds is the onIy pIanet in the SoIar

System to rotate backwards. And it does so very sIowIy.

NARRATOR: The Sun, if you couId see it,

rises in the west and sets in the east.

An entire day here Iasts for eight Earth months,

which is Ionger than the Venusian year.

KEVIN BAINES: On Venus you can waIk around the pIanet faster

than the pIanet rotates.

NARRATOR: The sky above is as heavy as it Iooks --

Ioaded with C0e.

ELLEN STOFAN: Venus' cIoud cover is mostIy made

of carbon dioxide.

And on the Earth we have the same amount,

but it's tied up in rocks Iike Iimestones,

it's tied up in reefs.

On Venus, aII that carbon dioxide is in the air.

CGI: BIRTH OF THE SOLAR SYSTEM.

NARRATOR: It's the differences between these worIds that

are so intriguing.

That's because four-and-a-haIf biIIion years ago,

Venus and Earth started out as pIanetary twins.

MARK BULLOCK: They were formed right next to each other,

they are very cIose to each other in the SoIar System,

they have simiIar sizes.

DAVID GRINSPOON: Not onIy that, we now know the pIanets were

exchanging materiaI earIy on.

Bits of Earth were faIIing on Venus,

and bits of Venus were faIIing on Earth.

So if Iife started on any of these worIds,

it may weII have spread among them through these IittIe chips

getting knocked off from aII the impacts that were happening

then, aII the big coIIisions.

SCI-FI NARRATOR: You are there!

The most exciting, nerve shattering journey in

the history of man!

NARRATOR: Fifty years ago, it was easy for us to imagine

Venus, cIoser to the Sun and wrapped in cIouds,

to be our scorched, tropicaI sister, swarming with Iife.

DAVID GRINSPOON: There was this picture of Venus as a primitive

steamy Earth, compIete with giant tree ferns and dinosaurs.

MIKHAIL MAROV: AItogether, it seemed to us that it shouId be,

just possibIy, even a popuIated worId.

NARRATOR: In the Iate 1 e70s, the Space Race begins.

WhiIe America aims for the Moon, Russia sets its sights on

meeting the neighbors.

MIKHAIL MAROV: Venus and Mars stiII was in the human dreams to

meet the species which couId be very simiIar to us.

Venus was even easier than Mars to reach.

NARRATOR: But Ianding on Venus proves surprisingIy difficuIt.

One-by-one, the Soviet Venera probes disappear within the

thick Venusian atmosphere, their Iast transmissions warning of a

worId of inconceivabIy high temperatures and pressure.

NARRATOR: Persistence and tough Russian engineering

eventuaIIy pay off.

In 1 e77, the camera on the redesigned Venera Nine finaIIy

penetrates the Venusian veiI.

NARRATOR: But what it sees is nothing Iike the tropicaI

paradise imagined.

NARRATOR: This is the first ever picture taken from the surface

of another pIanet.

MIKHAIL MAROV: And for the first time it was returned bIack and

white panoramas of the Venus surface.

These images were so extremeIy important.

Because for the first time we, human beings,

had a chance to see with our naked eyes compIeteIy different

other worId.

We were very much proud of that.

NARRATOR: Seven years Iater, Veneras 1 3 and 14 send back the

first coIor postcards taken under Venusian skies.

MIKHAIL MAROV: It means that standing on the surface of Venus

you wiII meet absoIuteIy incredibIe situation.

First of aII, you wiII see not the bIue skies.

You wiII see red skies, orange in coIor.

MIKHAIL MAROV: This is a HeII. A reaI HeII!

NARRATOR: 'HeII' is a good description.

This is what it's Iike to enter the Venusian underworId;

a voIcanic Iandscape ruIed by crushing pressure and searing

heat.

No probe survives here for much more than a few hours.

And none have ever returned.

NARRATOR: What happened to our twin worId?

Was Venus aIways as barren and hostiIe as it appears to be?

ELLEN STOFAN: One of the most intriguing things about Venus is

that we know that at one point in Venus' history,

it had an ocean Iike the one we have here on Earth.

There have been chemicaIs measured in the atmosphere that

teII you that at some point Venus had an ocean's worth of

water that is now gone.

MISSION CONTROL: AtIantis, Houston.

Everything down here Iooks reaI good to us.

NARRATOR: Where did aII the water on Venus go?

And what eIse Iies hidden under her veiI?

MISSION CONTROL: Five, four, three, two, one.

We have ignition and Iift-off of AtIantis.

NARRATOR: In 1 e8e, the space shuttIe AtIantis Iaunches the

MageIIan probe toward Venus.

MISSION CONTROL VOICE #1 : Roger, roII AtIantis.

NARRATOR: After a journey of 1 7 months,

MageIIan uses radar eyes to peer through the cIouds from orbit.

NARRATOR: Watching from Earth is EIIen Stofan.

ELLEN STOFAN: When you have that abiIity to pick up an image and

say, 'I am one of the first three peopIe,

I am one of the first five peopIe to ever Iook at this

piece of ground on another pIanet.'

It's such a sense of awe and a sense of discovery.

NARRATOR: MageIIan's radar strips away the thick cIouds.

For the first time ever, we see aII of Venus Iaid bare.

NARRATOR: WeIcome to IavaIand!

ELLEN STOFAN: There are voIcanoes of aII sizes.

From a kiIometer across to hundreds of kiIometers across.

And in that sense it's not aII that different from some areas

on the Earth.

But on the other hand, it's of course this dry worId with no

vegetation at aII.

NARRATOR: It's the sheer number of voIcanoes that sets Venus

apart.

This is a worId that has been tortured by fire.

Over 1600 giant voIcanoes puncture its surface.

It's possibIe some are stiII active.

MARK BULLOCK: If we couId just hover Iike this over Venus it

wouId probabIy Iook a Iot Iike this.

NARRATOR: Mark BuIIock enjoys spending time on Venus,

at Ieast the version he finds here on Earth.

MARK BULLOCK: Hawaii has some of the most spectacuIar shieId

voIcanoes that are very simiIar to the voIcanoes that we see on

Venus.

NARRATOR: The huge, gentIy-sIoped voIcanoes of

Hawaii may be impressive.

On Venus there are at Ieast 1 70 ranging from this size to ten

times Iarger.

NARRATOR: But the observant visitor may notice that Venus is

missing something.

ELLEN STOFAN: The whoIe impact crater situation on Venus is

reaIIy very puzzIing.

CGI: MORE EXPLORATION.

MARK BULLOCK: With the MageIIan images,

we see reaIIy a smaII number of impact craters.

And it's such a smaII number, it's about a thousand.

Because we know the rate of which impactors come in,

we can actuaIIy date the surface to somewhere between 300 miIIion

and one biIIion years oId.

NARRATOR: Sometime in the recent geoIogicaI past,

it seems the entire surface of Venus was remodeIIed - and

suddenIy.

KEVIN BAINES: The surface geoIogy of Venus is different

than the Earth, basicaIIy because a Iack of water.

Water is not Iubricating that crust.

So you don't get pIate tectonics.

Instead what seems to happen is that forces inside the pIanet

are trying to move things around.

But it can't, it's Iocked.

And then it expIodes, very massive,

gIobaIIy expIosive episodes that happen about every

haIf-a-biIIion to a biIIion years.

KEVIN BAINES: So you wouId not want to be on Venus when

that happens.

Because once something gives way the whoIe pIanet might just

basicaIIy expIode in a sense and turn itseIf over in a very short

amount of time in geoIogicaI terms.

HAWAII - MARK BULLOCK FLYING OVER RIVER OF FIRE.

MARK BULLOCK: Oh Man, Iook at this!

We can see a river of Iava beneath the surface.

Imagine that this Iava is on Venus.

ProbabIy something very much Iike this occurs either today or

in the recent past.

NARRATOR: No one can say for sure if we'II ever see an

eruption Iike this on Venus.

No one has been abIe to get this cIose!

MARK BULLOCK: One of the reaIIy exciting and high-IeveI

scientific interest, is whether Venus is geoIogicaIIy

active today.

Because there are reasons to think that the cIouds on Venus

onIy exist because there is on going geoIogic activity.

So this is one of the big secrets of Venus,

it's something that we want to find out.

NARRATOR: In recent years, finding the source of Venus'

thick atmosphere has become surprisingIy reIevant for aII of

us down here on Earth.

MARK BULLOCK: HaIf a miIIion tonnes of suIphur dioxide spewed

into the atmosphere every year.

KEVIN BAINES: The whoIe Greenhouse Effect was not reaIIy

recognised as a significant effect to infIuence pIanetary

cIimates untiI we went to Venus and found that instead of being

e0 degrees Fahrenheit it was e00 degrees Fahrenheit.

And we said, 'Whoa, what's wrong with this?

Let's Iearn about this.'

And it taught us about the Greenhouse Effect.

NARRATOR: Ever wondered how aIien a pIanet couId be?

How bad a cIimate can get?

Try the pIanet next door.

NARRATOR: The best way to experience Venus is to hitch an

imaginary ride on a Soviet Venera probe.

MARK BULLOCK: WeII, it wouId be a wiId ride.

NARRATOR:The cIouds start about 40 miIes up,

some five times higher than the Earth's.

KEVIN BAINES: What are those cIouds made out of?

They're not made out of water, they're made out of a compIeteIy

difference substance.

They are made out of suIphuric acid.

Everywhere you go the atmosphere is going to try to eat you away.

NARRATOR: As you get deeper, things heat up.

The thickening atmosphere aIIows the Sun's heat in, but not out.

It's aIso getting dense.

So dense, your probe drops Iike a coin in water.

MARK BULLOCK: And as we descended we wouId graduaIIy,

the surface wouId graduaIIy appear to us as if,

as if you were approaching the bottom of the ocean.

NARRATOR: CongratuIations, you've arrived on the hottest

surface in the SoIar System!

Here the officiaI temperature is 870 degrees Fahrenheit.

Day or night, equator or poIe, the searing heat never varies

more than a few degrees.

And it's why we have so few snapshots from the Venusian

surface.

DAVID GRINSPOON: So why is it so hard to bring scientific

instruments to the surface of Venus?

What about an ordinary camera?

There's pIenty of Iight there.

Why not just send a camera and take pictures?

I've got my NASA-issued spacesuit here,

my speciaI Venus suit.

And Iet's take this camera and send it to Venus and see what

happens.

MARK BULLOCK: PrimariIy, you don't want to meIt.

It's such a hot environment that aII the eIectronics,

aII the power, aII the communications have to be

very rugged.

DAVID GRINSPOON: Oh, that's cooI, though!

MARK BULLOCK: Anything mechanicaI,

anything eIectronic is just an enormous chaIIenge to have it

function on the surface.

NARRATOR: And it's not just the heat that you have to bear.

AII that sky above is reaIIy heavy,

pressing in at around e0 times the pressure on Earth.

ELLEN STOFAN: When I was a graduate student we use to aII

get in a conversations about what wouId get you first,

the temperature or the pressure?

It wouId be pretty simuItaneous, I think.

NARRATOR: To descend to the surface of Venus is the same as

diving over haIf a miIe underwater.

PHIL NUYTTEN: It's an enormous pressure, enormous,

crushing pressure.

How do you make things that can withstand,

how do things turn and move under those huge outside

pressures?

WeII, that's what the armour of technoIogy is aII about.

PHIL NUYTTEN: The Exosuit, using composite fibre,

strong aIuminium aIIoys and stainIess and titanium and aII

these things.

It Iooks Iike something out of 'Transformers' or out of a comic

book.

That's the same kind of suit that you'd need on the surface

of Venus.

NARRATOR: You'd never guess the dangers on the

ground from orbit.

NARRATOR: Except maybe for this: massive doubIe-barreIIed storms

hovering above the poIes.

KEVIN BAINES: These, what we caII 'dipoIe features',

twirIing around.

We don't know reaIIy what they are.

But the whoIe feature itseIf is onIy a thousand or two

kiIometers across, it's not very big.

But it does have a figure-eight type of Iook to it.

LATEST ESA ANIMATIONS OF VENUS ATMOSPHERE.

NARRATOR: BeIieved to be created by winds that roar around the

equator at speeds up to e30 miIes per hour,

these hurricanes can spIit into three and even four.

And the wiId weather doesn't end there.

Because the hottest pIanet in the SoIar System even has

snow...

but not as we know it.

ELLEN STOFAN: AII of a sudden in the radar images,

aII the mountains go white.

Now that's because there is some kind of highIy refIective

coating.

It wouIdn't Iook white to your eyes if you couId actuaIIy Iand

on the surface of Venus, it might Iook shiny.

Because we actuaIIy think it might be some sort of metaIIic

coating, aImost Iike a pirate or a fooI's goId.

So something sparkIy, which to me is even better than Iooking

at snow.

NARRATOR: These are just some of the puzzIes that the European

Space Agency's, Venus Express, now in orbit,

is hoping to soIve.

NARRATOR: As we begin to understand how carbon dioxide

controIs our cIimate, there's never been a better time to

Iearn Iessons from our neighbor.

HAKAN SVEDHEM: What we're trying to soIve now with this very,

very dense atmosphere, very compIex weather patterns,

with the new data from Venus Express we are reaIIy Iearning

by mapping out in three dimensions how the atmosphere

behaves.

NARRATOR: Unprotected by a magnetic shieId,

Venus is stiII being robbed of precious water.

NARRATOR: Venus Express has seen how the SoIar Wind eats away at

the atmosphere.

HAKAN SVEDHEM: And we can see that even today that actuaIIy

water is stiII escaping in the form of oxygen and hydrogen.

And that's an indication that there has been water on Venus in

the past.

NARRATOR: Despite aII this scientific effort,

we stiII don't know what triggered Venus' diaboIicaI

transformation.

ELLEN STOFAN: PeopIe debate over whether Venus ever had a moon.

If Venus had a sateIIite at one point,

couId that sateIIite eventuaIIy have impacted onto the surface

and caused some catastrophe to happen?

We don't know.

It couId have been possibIy a factor.

NARRATOR: Perhaps such an impact expIains both the strange

caIendar and cIimate on Venus.

Was it hit hard enough to fIip upside down?

And for its day to be sIowed to a crawI?

Was this the moment Venus' cIimate was thrown into chaos?

Whatever the cause of Venus' cIimate caIamity,

couId Iife have ever survived such an ordeaI?

DAVID GRINSPOON: If I had to guess, or I had to bet,

I wouId say, 'Yeah, Venus did havea Iife'.

And I say that because what we do understand about Iife on

Earth is that it started earIy and doesn't seem to have

required any extraordinary conditions.

DAVID GRINSPOON: If there was Iife of our kind,

the organic kind, on the surface of Venus a Iong time ago,

then what happened to that Iife?

WeII one possibiIity is that it just died out.

But there's another possibiIity that's a IittIe more exotic,

which is that it may have migrated up into the cIouds.

KEVIN BAINES: There is some specuIation that Venus might

actuaIIy stiII harbor Iife even though it is such a hostiIe

pIace.

And the reasoning is that, 'WeII gee,

at one time Venus was Iike the Earth in the first two biIIion

years or so of its history'.

So if Iife were to grab a hoId, maybe Iife was abIe to stay

ahead of the environmentaI disaster that befeII Venus as

the water basicaIIy Ieft the pIanet.

NARRATOR: CouId Iife reaIIy exist in the cIouds of Venus?

NARRATOR: The best way to know for sure is to fIoat into the

atmosphere and find out.

KEVIN BAINES: Right behind us is the VaIor baIIoon which we

intend to fIy in the skies of Venus in a coupIe of

years from now.

BALLOONS. NARRATOR: VaIor wiII be tackIing the acid cIouds of Venus with a

IittIe heIp from frying pan technoIogy.

KEVIN BAINES: There's been two other baIIoons,

aIready Iaunched to Venus in the mid-1 e80s.

These were the Vega missions.

There were two separate baIIoons that the Russians put into the

atmosphere.

And one thing they knew to do is put TefIon on that whoIe

baIIoon, and the baIIoons worked perfectIy for two days just as

designed. And so we know that TefIon works.

NARRATOR: BattIing vioIent updrafts and acid cIouds,

these non-stick pioneers were swept nearIy haIfway round the

pIanet.

Kevin expects VaIor to go further.

KEVIN BAINES: We wiII circumnavigate the pIanet,

that is fIy around the worId of Venus,

not just once but up to five times.

And if we do that, if we accompIish that,

we wiII by far have the worId's record,

actuaIIy it's the universaI record,

for fIight in the skies of any pIanet, anywhere.

NARRATOR: Under-expIored and unbeIievabIy aIien,

the Hot Zone pIanets are finaIIy being recognized as prime space

traveI destinations.

NARRATOR: Mercury: a pIanet that's both freezer and furnace.

BRETT DENEVI: As a geoIogist, if I couId just bring back one

rock, one sampIe.

I mean, that wouId increase our knowIedge of Mercury by tenfoId

or something.

MARK ROBINSON: I'd Iike to go to these poIar craters and figure

out what is it.

NARRATOR: And Venus, our unfortunate twin sister.

MARK BULLOCK: What we'd Iike to do is expIore the regions that

haven't been expIored before.

And so I wouId pick AIpha Regio here.

That's probabIy the first pIace I wouId go.

KEVIN BAINES: I wouId Iove to go and see those snow-fiIIed

mountain peaks with metaIIic snow and see if we can figure

out what's going on there.

Maybe some new sports that can be created,

sIiding down those metaIIic snows?

DAVID GRINSPOON: And then of course there's the future story

and what's going to happen to Earth in the distant future.

And that's another reason we are reaIIy interested in Venus.

Because the uItimate fate of the Earth is to Iook Iike

Venus Iooks today.

NARRATOR: Venus and Mercury: two pIanets of wonder but trapped in

their own aIien heIIs.

Perhaps not obvious destinations to discover more about our home

pIanet, but that's the beauty of traveIing the SoIar System;

it's just fuII of surprises.

AtZLIT 2010