Episode 1 Nature's Weirdest Events

We live in a very weird world.

And the more we discover about our planet, the stranger it gets.

Every day, news stories reach us, stories that surprise us...

What is THAT?

..shock us...

Whoa!

..sometimes even scare us.

SCREAMING

Oh, my God!

We've scoured the globe to bring you the most curious creatures...

..the most extraordinary people...

I can stick almost anything to my skin without no glue.

..and the most bizarre behaviour...

..using eyewitness accounts and expert opinion to explore a weird world...

..of unexplained underwater blobs...

..flying goats...

..and glow-in-the-dark fish.

We examine the evidence, test the theories...

..to work out what on earth is going on.

In this episode, we'll explore an extraordinary relationship...

HE SPEAKS PORTUGUESE

..reveal prehistoric creatures that could come back from the dead

and find out why Spain is under attack from space balls.

It could be capable to destroy a house.

But first to America, and to the coast of California,

where, in February 2016, a gourmet restaurant became famous for a very

unexpected guest.

I came in, and yes, she was there,

in booth number 65, which is the best table in the restaurant,

right on the water.

To Chef Bernard's surprise, a tiny sea lion pup was sitting,

waiting for service.

I've been here for 21 years and I've never seen something like this.

He named her Marina.

And stranger still, she wasn't a one-off.

This sea lion pup turned up on the streets of San Francisco.

Another was found in a toilet.

Whilst this one was caught on CCTV indulging in a spot of shopping.

Up and down the coast, lots of these animals were giving up on the ocean

and moving inland.

Strange behaviour indeed.

And sea lions weren't the only animals behaving oddly

on the California coast.

Check this out.

During 2015 and 16, millions of pelagic red crabs washed up

like a crimson tide.

And deadly venomous sea snakes

that are usually only found in the tropics

littered the state's beaches.

But why were these marine creatures suddenly turning terrestrial?

Well, Chef Bernard's uninvited guest could give us a clue.

By seeking out a seafood restaurant, Marina was smarter than the other

sea lion pups because they all had one thing in common...

..protruding ribs,

glassy eyes.

These pups were starving.

Marina was just one of over 6,500 skinny pups

rescued across the state.

The pups that are coming in are extremely emaciated.

A lot of our pups come into us about six months old,

and they're coming in just barely over birth weight.

What was causing these starving pups to come ashore in their thousands?

Well, there's one last unexpected piece to this puzzle.

Just a week before Marina showed up

at Chef Bernard's restaurant, something

truly extraordinary made a sudden appearance

just 15km down the coast.

Wow! Look at that.

As the tide falls back along the beach in Coronado,

a piece of the past is unveiled.

You're looking at the remains of the 300-foot long SS Monte Carlo.

But the SS Monte Carlo sank back in 1937.

So where had this wreck suddenly appeared from?

And how can it explain the sea snakes,

crab invasion and sea lions starving to death?

Well, all these bizarre events

were just symptoms of something much bigger and much stranger.

2015-'16 was what's known as an El Nino Year -

a global weather event powerful enough to affect the whole planet.

Normally, trade winds in the Pacific blow from east to west,

dragging warm surface waters towards Indonesia and Northeast Australia.

Meanwhile, deeper colder waters in the east rise to the surface.

But every few years, the trade winds weaken and can't change,

bringing in warmer water to the West Coast of America.

And it's these unusually warm waters

caused by El Nino that explain our Californian conundrum.

They triggered severe storms

that washed away tonnes of sand and exposed

the long-lost wreck of the SS Monte Carlo.

And warm currents brought sea snakes and red crabs up from the tropics.

But why would a hotter ocean spell starvation for Marina and thousands

of other sea lions?

Well, there's still plenty of fish out there,

but not in the right place.

It shifted into the cooler waters,

further down below or further offshore,

and that's what El Nino does. El Nino brings in this really warm

water current, and so, their cold-water prey

move with the cold water.

Adult sea lions can follow the fish offshore,

but breeding mothers and pups can't.

Many perished, but the lucky ones were rescued.

And Chef Bernard waved a fond farewell

when Marina returned to the wild.

Whoo! She really, really regained a lot of weight,

so she went from 20lb, became 40, 45lb.

So she was healthy, she was happy,

she was sassy and she was like, "Hey, Chef Bernard,

"time to go back in the big great blue!" And that's what we did.

So, a sea lion sauntering into a seafood restaurant was just a small,

skinny symptom of the world's largest weather phenomenon.

And the 2015-2016 El Nino was no ordinary El Nino.

It was the strongest since the 1950s and its effects were felt far wider

than the Sunshine State.

Yes, this was some seriously weird weather.

Yes, whilst strange weather was to blame for the peculiar events in

California, our next mystery was washed up by unusual currents

off Brazil.

Every June, 71-year-old Joao Pereira waits for his best friend,

Dindim, to arrive.

HE SPEAKS PORTUGUESE

They haven't seen each other for months,

because Dindim's been away at sea.

But finally, the wait is over.

Sorry, I didn't tell you, did I?

Dindim's a penguin.

A Magellanic penguin, to be precise.

And for the past five years,

Dindim and Joao have been devoted to each other.

So how did man and bird become such bosom buddies?

Joao's house backs onto Proveta Beach, near Rio De Janeiro.

In May 2011, he found Dindim on the sand,

barely moving and covered in oil.

Joao looked after the penguin.

He cleaned his feathers.

And fed him sardines.

After a few days,

when he thought Dindim was strong enough to fend for himself,

Joao took the penguin to a nearby island

and released him into the sea.

But just a few hours later, Joao heard squeaking in his backyard.

Much to his surprise, the penguin was back,

and made himself at home with Joao and his wife.

Dindim and Joao were inseparable for 11 months.

But then the penguin suddenly left.

Perhaps his instincts had kicked in and he'd gone to find his own kind.

Magellanic penguins live in the sea off of South America,

and sometimes they'll venture as far north as Rio here.

But once a year they have to head back south to Patagonia to breed.

So Joao could only imagine that Dindim, fully restored to health,

had hopped down off of the sofa,

taken to the sea and swum south to be reunited with

some of his fellow penguins.

But what's incredible

is that a few months later, much to Joao's delight,

Dindim returned.

HE SPEAKS PORTUGUESE

And the same thing happens every year.

Dindim heads out to sea for a few months to feed,

but he always returns to Joao.

So what's going on?

Why does Dindim keep coming back to Joao

rather than living with his own species?

Well, the answer may lie in the fact that the penguin was only about

a year old when Joao rescued him.

It could be that Dindim has imprinted upon Joao

to the extent that he sees Joao as his parent.

You see, when birds hatch,

they do so with little sense of identity.

They have to look around them to see what they are and how to behave.

And sometimes, if the first thing they see is a human,

they bond to it for life.

So perhaps this special relationship is due to some kind of

delayed imprinting. A case of mistaken identity.

But there could be another possibility that Dindim sees Joao

not as a parent, but as his partner.

You see, Dindim always returns around July,

which is the beginning of the penguin breeding season.

Other Magellanic penguins are in Patagonia then,

raising a family with their mate.

So is Dindim's affectionate behaviour actually

an attempt at courtship?

Well, it's not quite that simple.

Penguins are usually very loyal to the places that they spend their

summer months.

They breed in Patagonia,

they usually come back to the very same beach every year and they nest

in the very same hole every year with the same partner.

Most of them are like that.

Because Dindim spends so long with Mr Joao on Proveta Beach

he probably imprinted and learned that

that place is a safe place to be,

and is the place he has to go during the summer months.

So it seems that because Dindim spent his formative first summer

with Joao, he now sees that beach as his home.

Whatever the biological explanation may be,

the warm fuzzy feeling between

this penguin and his pal is clearly mutual.

So Dindim is usually very calm and comfortable and happy around

Mr Joao, and the opposite is true as well.

He is in heaven when Dindim is around.

I would say this is a friendship, why not?

What better definition for friendship than that?

Without Joao's help, Dindim surely would have died.

His kind actions have earned him an unlikely new best friend.

While Atlantic currents delivered this penguin to a loving new home,

unusual weather revealed a puzzle in the permafrost.

Siberia. Where temperatures often fall to minus-40 degrees.

And the ground is frozen solid year round.

But in August 2015,

a freak flood in the Sakha Republic exposed a fresh patch of tundra.

Scientists working in the area

stumbled across a weird-looking lump.

They chipped away at the block of ice...

Something furry emerged.

The scientists had uncovered two frozen animals,

but what could they be?

Wild dogs?

Polar bears?

No, this was something even more extraordinary.

A couple of very young lion cubs.

Wait a minute.

Lions in Siberia, how could that be?

I mean, we all know that lions roam the plains of Africa here.

And that there is a small population over here in north-western India.

But that's still more than 3,000 miles away from Siberia, here.

So how did those cubs turn up so far from home?

Well, in fact, the icy Siberian tundra was their home.

But not for 10,000 years.

These are baby cave lions, and they've been extinct for millennia.

Cave lions were around from a little over 300,000 years ago,

when we first find them in Europe.

To approximately between 14,000 and 10,000 years ago

was when they started to disappear from most of the range.

Cave lions were about 10% bigger than modern African lions

and roamed most of the Northern Hemisphere,

from Alaska to eastern Russia.

After detailed investigation,

biologists hypothesise that the cub's mother

left them in a den while she went off hunting.

And then while she was away,

a landslide caused the den to collapse,

and the cubs perished.

But if these cubs have been dead for over 10,000 years,

how do they look so good for their age?

Well, a simple demonstration should make that clear.

But I warn you, it's not pretty.

Look away if you're squeamish.

Left alone at room temperature,

a chicken decomposes within a week or so.

Bacteria and maggots make short work of the carcass.

But if we simulate the Siberian permafrost,

the chicken is frozen in time.

It's not just icy temperatures

that keep the flesh nice and fresh, though.

A combination of a lack of oxygen and no sunlight

also meant the cubs were preserved for thousands of years.

A chance in a million for biologists.

From a paleontological standpoint, it's a hugely significant find.

We very rarely get soft tissue preservation of extinct animals.

Not just the skeleton, but all the soft tissue, you know,

all the muscles and the brain and the fur.

It's just amazing.

And the soft tissue is the final twist in this Siberian story.

You see, not content with merely uncovering these cubs,

biologists plan to do the unthinkable.

To clone the cave lion.

To bring it back to life.

But how?

Well, science has progressed a lot since the first mammal was cloned

back in 1996.

'Scientists in Scotland have produced the first-ever clone

'of an adult animal.

'Dolly, a seven-month-old sheep,

'was created in a laboratory using a cell from another sheep.

'The new step involves taking a cell from an adult sheep

'and removing the genetic material from it.

'The genes are then inserted into an empty egg cell taken from another

'sheep. The egg is then used to start a pregnancy,

'the offspring being a clone.'

If intact DNA could be extracted from the cave lions then, in theory,

they could be brought back from extinction.

Korean biologist Hwang Woo-suk is taking tissue samples from the cubs.

Russian and Korean scientists are already working on cloning

ancient mammoths.

And as far fetched as this Jurassic dream sounds,

it might just be possible.

You see, they don't need pristine DNA to try and bring back

the cave lion, or, in this case, the mammoth.

Let's imagine that these parts of this jigsaw represents the good

mammoth DNA that they have.

The problem is...they've only got half a mammoth.

But their plan is to combine it with modern-day elephant DNA,

and what they end up with is a sort of hybrid embryo,

not an exact mammoth clone, but, perhaps,

something pretty close to it.

Even if scientists manage to create a viable embryo,

that's just the first step.

I think what people forget with cloning is that

you need a host animal.

And you need many, many replicates in order to get any sort of success.

So dozens, to potentially hundreds, of surrogate mothers.

Of course, if you look at modern lion populations,

they are plummeting. Just in the last few decades,

the lion populations have been cut almost in half.

So the amount of resources that would go into cloning the cave lion,

I think, could be much better spent on saving the lions

that are around today.

The possibility of cloning animals like cave lions and mammoths is

undeniably exciting.

But it's my duty to tell you that, at the moment,

a real-life Jurassic Park is still some way off.

So, whilst El Nino forced starving sea lions inland,

usual currents carried this Patagonian penguin to Rio.

And a freak flood gave new life to prehistoric lion cubs.

When weird weather strikes,

it can transport animals into some very unlikely places.

Coming up...

A selection of superpowers...

an exceptionally alluring insect...

and an invader destroying houses in the suburbs.

But first, we discover how one Scottish woman's

remarkable sense of smell could change the future of medicine.

I've always smelt things.

If I can help it, I don't go in to cake shops,

it's a smile that I don't particularly like.

Joy Milne's world is dominated by scent.

And her exceptionally sensitive nose

affects the way she perceives people.

People just don't smell, they have layers of smell.

They've got a perfume or a spray on,

but then they've got clothes

which they have then washed in a fabric softener.

Then they've got their body smells.

So, for me, a person has at least two or three different smells.

To Joy, every person has a distinct odour.

Including her husband, Les.

So she noticed straightaway when his scent suddenly changed.

'Out of the blue,'

I could smell this very musky,

very heavy smell on him.

Joy worked as a nurse, while Les was an anaesthetist.

She assumed that his unpleasant body odour was down to working long hours

in theatre.

I did say to him,

"I'm sorry, but you're not, you know, washing enough."

And it became quite a contentious sort of thing,

because he was showering.

Over the next few years,

Joy noticed that Les's musky scent became stronger.

And he developed other problems.

Les was a keen sportsman,

but his coordination began to falter.

We'd play squash until our late 30s,

things like he was missing the ball.

He couldn't keep up in the game,

because usually he beat me no bother at all.

Les's personality changed too.

He was generally known to be an extremely laid-back person.

He became irritable about things.

He became aggressive, sometimes.

It's very strange living with somebody that you've known

since he was 16, change quite a bit in the gap of ten years.

So what could be causing these

worrying mental and physical symptoms?

Les was eventually diagnosed with Parkinson's disease,

a progressive disorder of the nervous system,

but not a condition that had ever before been associated with a change

in body odour. So could there possibly be a connection here?

When Joy went to a Parkinson's support group,

she made a sensational discovery.

And she couldn't wait to tell her husband.

I said to him, "These people smell the same as you."

And he said, "What are you talking about?"

And I said, "Those people smell exactly the same as you."

Joy seems to have an extraordinary ability to sniff out Parkinson's.

As medical professionals,

Joy and Les realised that this could be ground-breaking.

There's currently no simple way to diagnose Parkinson's and

Joy's nose could hold the key to developing a test.

So Joy approached scientists working on the disease

and told them about her strange ability.

Together, we devised a method to try and see if we could understand

what it was, what the smell was.

We did a control experiment where we had people suffering from

Parkinson's, fairly late-stage on, and people who weren't.

We made them wear T-shirts.

And we then cut the T-shirts up and put them in bags so that they were

anonymous and took them to Joy to smell.

And Joy was extremely good at identifying

the people who had Parkinson's.

Joy got all but one sample correct.

She thought one of the people without Parkinson's, in fact,

had the disease.

Perhaps her olfactory powers weren't foolproof after all.

But then, something incredible happened.

That person, about a year afterwards,

was diagnosed with Parkinson's disease.

Joy had been right all along.

What is mind-blowing here is that she could detect Parkinson's

simply using her nose -

well before any doctor could.

So what is it that Joy can smell?

It's all down to sebum.

That oily substance that coats our skin.

It's made up of thousands of different ingredients.

We identified approximately 9,000 unique molecules.

What we need to now do is to find out what the differences are between

a healthy person and someone with Parkinson's.

Once the team have identified which chemicals cause the distinctive

Parkinson's smell, they can develop a test to find those compounds

rather than relying on Joy's nose.

We'll be able to diagnose this disease at an early stage,

before some of the devastating symptoms have started.

And an early diagnosis is crucial to managing this condition effectively.

But there's something even more exciting.

The smell that Joy first discovered

could also help develop new medicines.

'Because it happens so early,'

because there's a change so early on in the start of the disease,

it may tell us something really crucial about the beginning stage of

the disease, which will open the door to new treatments and a better

understanding of how it progresses.

Sadly, Les died in 2015.

But Joy is determined to use her finely-tuned sense of smell to help

others and raise awareness of the early symptoms of Parkinson's.

You're given what you're given in life.

I've had this smell, I've married this person,

they've then got Parkinson's.

And I've lived through it.

I don't want other people to have that, that problem.

It's horrendous. It is.

It really is. And I want that early diagnosis.

Joy's fortitude through such difficult times

is incredible in itself.

But the fact that she noticed a change in her husband's smell

and related it directly to his disease

could lead to massive leaps forward in medical science.

You know, sometimes it's just the quirky little things in biology -

in this case, an extraordinary sense of smell -

which leads to such rapid progress.

Whilst Joy's super-sense could help fight Parkinson's disease,

our next weird tale features an animal with a super-secret weapon.

The remote Zagros Mountains in western Iran -

home to an animal found nowhere else on earth.

A strange spiderlike creature.

It's the height of the breeding season,

and birds are desperately trying to find enough food

for their growing chicks.

So this looks like a perfect, juicy meal.

But on this occasion, it's the bird that becomes dinner,

for a perfectly camouflaged viper.

And it looks like the snake is joining forces

with the creepy-crawly.

That is astonishing.

What is that weird spider thing?

What is it doing?

Could it really be helping the snake to catch its prey?

Well, in a sense, it is.

But the truth is much, much more bizarre than that.

Have a closer look.

Look, that creepy-crawly appears to be clinging on to the snake's tail.

Reptile expert Steven Anderson was mystified when

he first saw a specimen in the Chicago Field Museum

over 40 years ago.

I was there to identify a collection of reptiles from Iran.

I happened to open a bottle.

I pulled the snake out and looked at it,

and I didn't know what to think of it at that point.

On closer inspection, Steven got a shock.

I was very startled to see that it was actually an ornamentation

of the tail itself.

Yes, this thing was actually part of the snake.

But what was it?

With just a single preserved specimen,

it was impossible to work out whether it was just

a ghoulish anomaly or a whole new species.

For four decades, the mystery remained unsolved.

Until, in 2014, when the snake was filmed in the wild.

And the truth was finally revealed.

That strange structure is a lure,

used to entice prey.

It moves its tail back and forth along the ground,

and because of the strange appendage,

these elongated scales look like legs when it moves,

like a spider moving around.

And the end of the tail, the last two scales,

form what looks like the body of this creature.

This one seems to be very attractive to birds.

This surreal snake was new to science,

and imaginatively named...

..the spider-tailed pit viper.

Other animals use a similar strategy.

A humpbacked anglerfish attracts prey with its built-in fishing rod.

And this turtle's wormlike tongue fascinates its unsuspecting victim.

It's a very useful trick.

Just sit still and tempt your dinner to within striking distance.

And the viper attacks within two-tenths of a second.

Then it just waits for its venom to take effect.

That tantalising tail is THE most elaborate lure in the reptile world.

That is one sneaky snake.

And whilst I recognise that a snake with a tail like a spider

is the stuff of nightmares to many people,

for me, this thing is a triumph of evolution.

It's remarkable.

From a predator that hides in plain sight, we now travel to Florida,

where intruders are lurking in the undergrowth.

Miami.

Glamorous. Cool.

Playground of the rich and beautiful.

But a recent invasion is distressing local residents.

Oh, my God. I will never go out.

I will not let my kids go outside and play.

We didn't know what they were in the beginning.

They would start climbing up the trees and just seemed to stay there.

We began to see...hundreds.

Properties are being overrun by alien creatures.

I found one the size of my hand.

So what's the cause of all of this anxiety?

They are big. There are slimy

and a lot of people think they're downright disgusting.

Snails.

Large snails.

They're everywhere.

I know what you're thinking,

have the residents of Miami gone completely crazy?

I mean, every garden has slugs and snails, doesn't it?

Well, it might. But not snails like this one.

You see, this is a giant African land snail.

They can grow to up to 20 centimetres.

They can live for up to nine years.

These are monster snails.

And they are causing panic because

they don't just munch on a few garden plants.

They'll eat over 500 different crops.

They'll even devour people's homes.

Yes, really.

They're eating the concrete.

Because they're getting calcium out of that to help build

their shells stronger and bigger.

But what's most worrying is that in Florida,

they may carry a type of meningitis

that can be passed on to humans via their slime.

So these snails are a menace to human health and to the economy.

But where have they all come from?

Well, they are native to Africa.

No-one is completely sure how they first came to Florida,

but people have been caught smuggling them into the country.

A lady coming back from Nigeria last year

had 12 of them hidden under her dress.

A man coming back from the Philippines,

and he had one giant African snail in each one of his suit pockets.

However they arrived,

with plenty of lush vegetation and no natural predators,

the invading snail population has boomed.

Meet Harry the snail.

Or maybe Harriet the snail,

You see, it's difficult to ascribe a name to a snail,

because they are hermaphrodite.

They have both male and female reproductive apparatus.

This is a real benefit to them.

They don't have to go through that rigmarole of finding and then

charming a mate. They can simply get on with reproduction.

And they do. They can produce up to 1,000 eggs a year.

I mean, you do the maths.

These things are unstoppable.

So the risk of disease and downright destruction

means that local authorities are under pressure

to eradicate these slimy intruders.

We created a giant African land snail incident command.

We're doing a lot of outreach in schools, at events,

we do billboards,

radio ads and television ads.

The authorities rely on people ringing in with their sightings.

I started seeing signs on the back of trucks which said,

"Call the state of Florida."

As soon as I saw this meningitis...

..that scared me to death.

They came several times a week,

and they would pick up hundreds of them and put them in plastic bags.

And, you know, take them away.

The snail squad seem to be getting on top of the slow-mo swarm.

We've collected over 162,000 giant African land snails.

The idea is get the population down. And we've accomplished that.

But if these snails can lay 100 eggs at a time,

to get on top of the problem,

the authorities are going to need to find every single last one of them.

And until recently, that's been an almost impossible task.

But now, the authorities have a secret weapon.

Meet Sierra.

Come on, let's go.

We use canines because they can get to places where humans can't.

They can smell that snail and go after it and alert us that there are

giant African snails there.

Yeah! Good girl, babe.

You found it.

Good girl.

Good girl.

In Shannon's garden, the snail squad's efforts seem to be working.

It's been amazingly successful because for months,

I have not seen a snail.

But Mark and his team must remain vigilant.

Just the other day we found a 4.8 incher, which is an adult,

which means that there are children, or neonates

that are out there in the wild. We have to keep looking for them.

So the snail squad's efforts

and their search for these marauding molluscs

is set to continue.

And Sierra's sniffing services are going to be needed for a while yet.

From a super-sensitive nose that can sniff out Parkinson's disease

and a snake with a hidden weapon...

..to a super-sized house-eating snail,

there's no doubt that nature's superpowers

can lead to some truly bizarre consequences.

Coming up...

A strange glowing slime.

And alien objects that fell from the sky.

But first, we head to the holiday resort of Fethiye

on the Turkish coast.

On the 9th of July 2015,

dive instructor Lutfu Tanriover jumped into the

calm blue waters of the Mediterranean,

something he'd done hundreds of times before.

I have been diving the area for eight years.

And at least once a week we are going to that dive site.

Little did he know what he'd find under the waves this time.

A blob of baffling proportions.

It was three, four metres wide.

And drifting about 22 metres in the middle of the water.

It was a very, very big bubble.

We were all fascinated by it because nobody had ever seen

something like that before.

I decided to call it The Thing.

Lutfu posted this footage of The Thing online,

where it grabbed the attention of marine biologist Steve Haddock.

So what did he think this bewildering blob could be?

When you see something like that,

there's only a few things that it might potentially be.

One of the things is a pyrosome.

This is a colony of organisms that can form

either a small tube or, actually, one species can form very,

very large tubes that divers can actually swim inside of.

But the thing that Lutfu filmed was a ball.

Not a tube.

So if it wasn't a colony of individual creatures,

what was this awe-inspiring orb?

And where had it come from?

The secret to the blob's source lay inside the sphere.

You see, initially, it looked translucent.

See-through. But then, under closer inspection,

Lutfu could see something inside.

When you go next to it, we put the torches in it,

and then we saw with the torches, we have seen so many particles in it.

These particles provided a vital clue.

You see, this isn't a single giant blob at all.

But millions of tiny individual spheres.

Squid eggs.

Instead of having them individually,

they're like little snacks for other organisms to live on,

they embed them in a giant gelatinous mass.

It's a strategy that certain species of squid use in the open ocean

where there are lots of hungry mouths around.

Predators could come from any direction,

and you have very few ways to hide or secure your eggs.

But if you put them in this mass,

it's large enough, it excludes all the predators

that are smaller than that.

This enormous egg mass is the squid's way of maximising

its offspring's chances of survival.

Blobs like this are rarely seen,

they last just a few days before breaking up.

Then each baby squid will face the world alone.

But there's one puzzle left.

So how does a relatively small squid produce something so huge?

Well, its eggs start off quite small.

But they expand massively in sea water.

It's a bit like frog spawn on steroids.

So this vast blob of jelly is the secret to a squid's success.

Protecting its precious eggs from predators.

Whilst this bizarre ball appeared underwater...

..our next mystery was spotted underground.

In March 2016,

Anthony Roberts was exploring this old slate mine in North Wales.

Scoping out new areas for guided tours.

His normal route in and out was flooded,

so he used the emergency exit tunnels instead.

On the way out, something stopped him in his tracks.

A very strange, very bright luminous green material.

It kept glowing.

This glimmering stuff has been found in dark nooks and crannies

around the globe.

'Wow!'

In Cornwall...

Germany...

-'Holy

-BLEEP,

-look at that down there.

'It is, it's glowing.'

And even New York state.

So what on earth could be producing this eerie green glow?

Well, some rocks have the ability to fluoresce,

the minerals within them can absorb light and then re-emit it.

Like glow-in-the-dark stickers.

True, but could this glowing green goo actually be alive?

In Africa, there is a fungus that lights up the forest floor.

It uses the luminous enzymes to breakdown leaf litter.

The locals call it chimpanzee fire.

But there was something completely unfathomable about the green goo

that Anthony found in Wales.

It had the disturbing ability to vanish before his eyes.

It wasn't until I

took a few steps closer,

looked back at it from a slightly different direction and realised

it's completely disappeared.

I couldn't see it at all.

So what was this glistening substance that glowed one moment

and was gone the next?

In the past, people believed it was the treasure of goblins.

Probably hundreds of years,

the stories about goblins hiding their gold in caves

and all sorts of dark places.

People walking past dark caves and such places see this glow of

emeralds in the back and they go in and say,

"This is the treasure, we're going to go in..."

And you go in and grab a bit and you come out, and of course,

it's not there. It's completely gone.

So, obviously, it's goblins, what else could it be?

In fact, these aren't sparkling gems hidden by mythical creatures.

But the answer is almost as magical.

It's a very clever trick by a moss

that lives in these special circumstances.

A moss called goblin gold.

But this is no ordinary moss.

It's developed some very special cells that allow it to live

where there's almost no light.

So how does it work?

The front of each cell is curved like a lens,

this focuses light rays and boosts the amount of light reaching the

chloroplasts - those parts of the plant that produce energy

through photosynthesis.

The reason it glows is that some of the light is reflected back out

through that lens.

And this is the key to the moss's mysterious disappearance.

Those reflected light rays can only be seen from one particular angle.

And Anthony happened to stop in just the right place.

If I'd been one step higher or one step lower,

I wouldn't have noticed it.

Imagine that.

Lurking out there in the dark, all across the UK,

there's green gold just waiting to be discovered.

Fantastic.

For our final dose of weirdness, we head to southern Spain.

Normally, Calasparra is a small, sleepy town.

But in November 2015, a local farmer found something out of this world.

A peculiar, alien object appeared out of nowhere.

I saw a black ball about 60 centimetres across

lying close to the bottom of the bank,

and a big dent where it hit the ground.

When I saw it, I called the police straightaway.

They told me not to touch it.

The police cautiously collected the huge hairy ball

and took it away for analysis.

And this wasn't a one-off.

That month, two more of these eerie orbs turned up in the region.

And around the globe, there were reports of more weird objects

suddenly appearing. These odd balls turned up in Vietnam.

Another was discovered in Brazil.

But where had they all come from?

Back in Spain, there was a clue.

Witnesses in the town said they saw strange objects,

like a cluster of fire, which then dispersed and fell.

They told me there were between four and six unidentified flying objects.

Burning UFOs falling from space.

Understandably, the mayor was very concerned.

We were worried that it might happen again, falling on a primary school,

someone's home, or a playground.

So what could explain these menacing missiles that tumbled to Earth?

Whoa!

Well, our skies are the scene of some strange sights.

One possibility is that they were some sort of mysterious meteorite.

This one caused confusion when it landed in Kenya.

'Residents of the Ol Donyo Sabuk area hear a loud noise

'from the sky above. But there's no aircraft in sight.

'Instead, a strange object, whose appearance left many puzzled.'

And, you know, falling meteors are more common than you might think.

Every day, the Earth is bombarded with thousands of pieces of rock

that come from outer space.

Now, as they enter the atmosphere,

a tremendous friction is generated and they burst into flames.

But if they survive that re-entry, then they become meteorites.

Irregularly shaped, really heavy pieces of rock.

But these space balls clearly weren't made of stone.

So if they weren't meteorites, what were these alien orbs?

At first, the scientist tasked with analysing the space balls was

absolutely flummoxed.

What a strange artefact. What a strange object.

I've never seen anything

similar before.

Juan Antonio tested every bit of the ball.

We found out

the cover of the balls was made of carbon fibre.

We discovered that

some parts of the balls were made of a special stainless steel,

and the metal of the main body

was made of titanium.

Right, so let's just get this straight.

Fireballs, made of carbon fibre and titanium,

are battering us from beyond our planet?

So are these cannonballs a sign of intelligent life?

Well, yes.

You see, they are from outer space, but we put them there.

These balls are fuel tanks, yes.

Fuel tanks for powering rockets.

'One small step for man.

'One giant leap for mankind.'

Since we began exploring space in the 1960s,

nearly 7,000 satellites have been sent into orbit.

And the metal balls found in Calasparra,

Vietnam and Brazil

are the remains of the small fuel tanks that are used

to manoeuvre them. So, if they're supposed to be up in space,

how did these fuel tanks end up in Spain?

Well, sometimes satellites may break down or collide

and the debris can fall back to Earth,

or de-orbit.

In a given month, 10 or 20 objects will de-orbit,

that means they'll burn up in the atmosphere.

When we have control over a de-orbit, we nearly always aim for the

middle of the Pacific Ocean because it's a very big, uninhabited area.

The problem is, when certain larger bits of debris de-orbit,

larger pieces, fuel tanks etc,

we have no control over where they'll land.

We really won't know until very late in the de-orbit process.

Whilst most debris burns up,

robust parts like fuel tanks may survive re-entry.

Realistically, space junk poses little risk of injury.

It's much more dangerous hurtling around our planet.

A paint fleck will have the same kinetic energy as a rifle bullet,

and poses a real danger to spacecraft and asteroids.

There are now millions of bits of debris circling the Earth.

Some as big as a bus.

And any collisions with the satellites we rely upon

could jeopardise our whole way of life.

The internet may go down because we rely on space-based communications

more than ever in our connected society.

A lot of the banking industry and finance industry relies on

very accurate timing for high-frequency trading.

If we lost those timing signals, there could be financial chaos.

But don't worry, a global meltdown is highly unlikely.

Space debris is very carefully monitored so that satellites

can be moved out of harm's way.

So, those strange Spanish balls weren't a sign of an alien attack.

They were a symbol of the ever-increasing mass of space junk

that's circling our planet.

So, while Spain fell under attack by balls from space...

..an equally strange sphere was found underwater...

..and a mythical moss was uncovered underground.

So there. Just goes to prove that although the weird and the wonderful

can turn up in every corner of the globe,

the extraordinary is just as likely to appear on your doorstep.

Next time, we uncover some incredible creatures...

I had trouble breathing. I started to get chest pains.

I've never felt anything like that before.

..reveal some seriously spooky spectres...

It comes and goes.

It can be there for a second and then be gone.

..and find out why albatross chicks are planted in pots.