0:00:02 > 0:00:05We live in a very weird world.
0:00:09 > 0:00:13And the more we discover about our planet, the stranger it gets.
0:00:14 > 0:00:20Every day, news stories reach us, stories that surprise us...
0:00:20 > 0:00:22What is THAT?
0:00:22 > 0:00:23..shock us...
0:00:23 > 0:00:24Whoa!
0:00:26 > 0:00:29..sometimes even scare us.
0:00:29 > 0:00:30SCREAMING
0:00:30 > 0:00:31Oh, my God!
0:00:32 > 0:00:36We've scoured the globe to bring you the most curious creatures...
0:00:38 > 0:00:40..the most extraordinary people...
0:00:40 > 0:00:44I can stick almost anything to my skin without no glue.
0:00:44 > 0:00:46..and the most bizarre behaviour...
0:00:49 > 0:00:53..using eyewitness accounts and expert opinion to explore a weird world...
0:00:55 > 0:00:57..of unexplained underwater blobs...
0:00:59 > 0:01:00..flying goats...
0:01:02 > 0:01:03..and glow-in-the-dark fish.
0:01:06 > 0:01:10We examine the evidence, test the theories...
0:01:12 > 0:01:14..to work out what on earth is going on.
0:01:34 > 0:01:39In this episode, we'll explore an extraordinary relationship...
0:01:39 > 0:01:42HE SPEAKS PORTUGUESE
0:01:42 > 0:01:47..reveal prehistoric creatures that could come back from the dead
0:01:47 > 0:01:52and find out why Spain is under attack from space balls.
0:01:52 > 0:01:56It could be capable to destroy a house.
0:01:59 > 0:02:03But first to America, and to the coast of California,
0:02:03 > 0:02:09where, in February 2016, a gourmet restaurant became famous for a very
0:02:09 > 0:02:10unexpected guest.
0:02:12 > 0:02:14I came in, and yes, she was there,
0:02:14 > 0:02:19in booth number 65, which is the best table in the restaurant,
0:02:19 > 0:02:21right on the water.
0:02:23 > 0:02:28To Chef Bernard's surprise, a tiny sea lion pup was sitting,
0:02:28 > 0:02:30waiting for service.
0:02:30 > 0:02:33I've been here for 21 years and I've never seen something like this.
0:02:38 > 0:02:40He named her Marina.
0:02:40 > 0:02:43And stranger still, she wasn't a one-off.
0:02:46 > 0:02:50This sea lion pup turned up on the streets of San Francisco.
0:02:50 > 0:02:53Another was found in a toilet.
0:02:53 > 0:02:57Whilst this one was caught on CCTV indulging in a spot of shopping.
0:03:02 > 0:03:06Up and down the coast, lots of these animals were giving up on the ocean
0:03:06 > 0:03:08and moving inland.
0:03:08 > 0:03:10Strange behaviour indeed.
0:03:12 > 0:03:15And sea lions weren't the only animals behaving oddly
0:03:15 > 0:03:17on the California coast.
0:03:17 > 0:03:19Check this out.
0:03:19 > 0:03:24During 2015 and 16, millions of pelagic red crabs washed up
0:03:24 > 0:03:25like a crimson tide.
0:03:29 > 0:03:31And deadly venomous sea snakes
0:03:31 > 0:03:33that are usually only found in the tropics
0:03:33 > 0:03:35littered the state's beaches.
0:03:39 > 0:03:44But why were these marine creatures suddenly turning terrestrial?
0:03:47 > 0:03:52Well, Chef Bernard's uninvited guest could give us a clue.
0:03:52 > 0:03:56By seeking out a seafood restaurant, Marina was smarter than the other
0:03:56 > 0:04:00sea lion pups because they all had one thing in common...
0:04:02 > 0:04:04..protruding ribs,
0:04:04 > 0:04:06glassy eyes.
0:04:06 > 0:04:09These pups were starving.
0:04:11 > 0:04:16Marina was just one of over 6,500 skinny pups
0:04:16 > 0:04:19rescued across the state.
0:04:19 > 0:04:22The pups that are coming in are extremely emaciated.
0:04:22 > 0:04:24A lot of our pups come into us about six months old,
0:04:24 > 0:04:27and they're coming in just barely over birth weight.
0:04:32 > 0:04:37What was causing these starving pups to come ashore in their thousands?
0:04:41 > 0:04:45Well, there's one last unexpected piece to this puzzle.
0:04:45 > 0:04:48Just a week before Marina showed up
0:04:48 > 0:04:51at Chef Bernard's restaurant, something
0:04:51 > 0:04:54truly extraordinary made a sudden appearance
0:04:54 > 0:04:57just 15km down the coast.
0:04:58 > 0:05:02Wow! Look at that.
0:05:02 > 0:05:05As the tide falls back along the beach in Coronado,
0:05:05 > 0:05:07a piece of the past is unveiled.
0:05:07 > 0:05:12You're looking at the remains of the 300-foot long SS Monte Carlo.
0:05:14 > 0:05:19But the SS Monte Carlo sank back in 1937.
0:05:19 > 0:05:22So where had this wreck suddenly appeared from?
0:05:23 > 0:05:26And how can it explain the sea snakes,
0:05:26 > 0:05:29crab invasion and sea lions starving to death?
0:05:36 > 0:05:38Well, all these bizarre events
0:05:38 > 0:05:43were just symptoms of something much bigger and much stranger.
0:05:47 > 0:05:522015-'16 was what's known as an El Nino Year -
0:05:52 > 0:05:57a global weather event powerful enough to affect the whole planet.
0:06:01 > 0:06:05Normally, trade winds in the Pacific blow from east to west,
0:06:05 > 0:06:10dragging warm surface waters towards Indonesia and Northeast Australia.
0:06:11 > 0:06:17Meanwhile, deeper colder waters in the east rise to the surface.
0:06:17 > 0:06:21But every few years, the trade winds weaken and can't change,
0:06:21 > 0:06:24bringing in warmer water to the West Coast of America.
0:06:29 > 0:06:32And it's these unusually warm waters
0:06:32 > 0:06:36caused by El Nino that explain our Californian conundrum.
0:06:38 > 0:06:41They triggered severe storms
0:06:41 > 0:06:44that washed away tonnes of sand and exposed
0:06:44 > 0:06:47the long-lost wreck of the SS Monte Carlo.
0:06:48 > 0:06:53And warm currents brought sea snakes and red crabs up from the tropics.
0:06:56 > 0:07:01But why would a hotter ocean spell starvation for Marina and thousands
0:07:01 > 0:07:02of other sea lions?
0:07:04 > 0:07:07Well, there's still plenty of fish out there,
0:07:07 > 0:07:10but not in the right place.
0:07:10 > 0:07:12It shifted into the cooler waters,
0:07:12 > 0:07:14further down below or further offshore,
0:07:14 > 0:07:17and that's what El Nino does. El Nino brings in this really warm
0:07:17 > 0:07:20water current, and so, their cold-water prey
0:07:20 > 0:07:21move with the cold water.
0:07:22 > 0:07:25Adult sea lions can follow the fish offshore,
0:07:25 > 0:07:27but breeding mothers and pups can't.
0:07:29 > 0:07:32Many perished, but the lucky ones were rescued.
0:07:34 > 0:07:37And Chef Bernard waved a fond farewell
0:07:37 > 0:07:40when Marina returned to the wild.
0:07:40 > 0:07:43Whoo! She really, really regained a lot of weight,
0:07:43 > 0:07:46so she went from 20lb, became 40, 45lb.
0:07:46 > 0:07:48So she was healthy, she was happy,
0:07:48 > 0:07:51she was sassy and she was like, "Hey, Chef Bernard,
0:07:51 > 0:07:54"time to go back in the big great blue!" And that's what we did.
0:08:08 > 0:08:13So, a sea lion sauntering into a seafood restaurant was just a small,
0:08:13 > 0:08:17skinny symptom of the world's largest weather phenomenon.
0:08:17 > 0:08:22And the 2015-2016 El Nino was no ordinary El Nino.
0:08:22 > 0:08:28It was the strongest since the 1950s and its effects were felt far wider
0:08:28 > 0:08:29than the Sunshine State.
0:08:30 > 0:08:34Yes, this was some seriously weird weather.
0:08:37 > 0:08:41Yes, whilst strange weather was to blame for the peculiar events in
0:08:41 > 0:08:48California, our next mystery was washed up by unusual currents
0:08:48 > 0:08:49off Brazil.
0:08:53 > 0:08:58Every June, 71-year-old Joao Pereira waits for his best friend,
0:08:58 > 0:09:00Dindim, to arrive.
0:09:00 > 0:09:03HE SPEAKS PORTUGUESE
0:09:05 > 0:09:07They haven't seen each other for months,
0:09:07 > 0:09:10because Dindim's been away at sea.
0:09:10 > 0:09:12But finally, the wait is over.
0:09:20 > 0:09:21Sorry, I didn't tell you, did I?
0:09:21 > 0:09:23Dindim's a penguin.
0:09:25 > 0:09:28A Magellanic penguin, to be precise.
0:09:28 > 0:09:30And for the past five years,
0:09:30 > 0:09:34Dindim and Joao have been devoted to each other.
0:09:34 > 0:09:38So how did man and bird become such bosom buddies?
0:09:42 > 0:09:46Joao's house backs onto Proveta Beach, near Rio De Janeiro.
0:09:47 > 0:09:50In May 2011, he found Dindim on the sand,
0:09:50 > 0:09:53barely moving and covered in oil.
0:09:55 > 0:09:57Joao looked after the penguin.
0:09:59 > 0:10:01He cleaned his feathers.
0:10:05 > 0:10:06And fed him sardines.
0:10:09 > 0:10:10After a few days,
0:10:10 > 0:10:13when he thought Dindim was strong enough to fend for himself,
0:10:13 > 0:10:16Joao took the penguin to a nearby island
0:10:16 > 0:10:18and released him into the sea.
0:10:22 > 0:10:27But just a few hours later, Joao heard squeaking in his backyard.
0:10:28 > 0:10:32Much to his surprise, the penguin was back,
0:10:32 > 0:10:35and made himself at home with Joao and his wife.
0:10:51 > 0:10:55Dindim and Joao were inseparable for 11 months.
0:10:55 > 0:10:58But then the penguin suddenly left.
0:10:59 > 0:11:04Perhaps his instincts had kicked in and he'd gone to find his own kind.
0:11:09 > 0:11:13Magellanic penguins live in the sea off of South America,
0:11:13 > 0:11:17and sometimes they'll venture as far north as Rio here.
0:11:17 > 0:11:21But once a year they have to head back south to Patagonia to breed.
0:11:21 > 0:11:26So Joao could only imagine that Dindim, fully restored to health,
0:11:26 > 0:11:27had hopped down off of the sofa,
0:11:27 > 0:11:31taken to the sea and swum south to be reunited with
0:11:31 > 0:11:33some of his fellow penguins.
0:11:36 > 0:11:38But what's incredible
0:11:38 > 0:11:42is that a few months later, much to Joao's delight,
0:11:42 > 0:11:43Dindim returned.
0:11:43 > 0:11:48HE SPEAKS PORTUGUESE
0:11:49 > 0:11:52And the same thing happens every year.
0:11:53 > 0:11:56Dindim heads out to sea for a few months to feed,
0:11:56 > 0:12:00but he always returns to Joao.
0:12:00 > 0:12:01So what's going on?
0:12:01 > 0:12:04Why does Dindim keep coming back to Joao
0:12:04 > 0:12:07rather than living with his own species?
0:12:09 > 0:12:13Well, the answer may lie in the fact that the penguin was only about
0:12:13 > 0:12:16a year old when Joao rescued him.
0:12:18 > 0:12:22It could be that Dindim has imprinted upon Joao
0:12:22 > 0:12:26to the extent that he sees Joao as his parent.
0:12:26 > 0:12:27You see, when birds hatch,
0:12:27 > 0:12:30they do so with little sense of identity.
0:12:30 > 0:12:34They have to look around them to see what they are and how to behave.
0:12:34 > 0:12:39And sometimes, if the first thing they see is a human,
0:12:39 > 0:12:41they bond to it for life.
0:12:44 > 0:12:48So perhaps this special relationship is due to some kind of
0:12:48 > 0:12:51delayed imprinting. A case of mistaken identity.
0:12:54 > 0:12:59But there could be another possibility that Dindim sees Joao
0:12:59 > 0:13:02not as a parent, but as his partner.
0:13:04 > 0:13:08You see, Dindim always returns around July,
0:13:08 > 0:13:12which is the beginning of the penguin breeding season.
0:13:12 > 0:13:15Other Magellanic penguins are in Patagonia then,
0:13:15 > 0:13:18raising a family with their mate.
0:13:21 > 0:13:24So is Dindim's affectionate behaviour actually
0:13:24 > 0:13:25an attempt at courtship?
0:13:27 > 0:13:30Well, it's not quite that simple.
0:13:30 > 0:13:34Penguins are usually very loyal to the places that they spend their
0:13:34 > 0:13:35summer months.
0:13:39 > 0:13:40They breed in Patagonia,
0:13:40 > 0:13:44they usually come back to the very same beach every year and they nest
0:13:44 > 0:13:47in the very same hole every year with the same partner.
0:13:47 > 0:13:48Most of them are like that.
0:13:48 > 0:13:53Because Dindim spends so long with Mr Joao on Proveta Beach
0:13:53 > 0:13:56he probably imprinted and learned that
0:13:56 > 0:13:58that place is a safe place to be,
0:13:58 > 0:14:01and is the place he has to go during the summer months.
0:14:01 > 0:14:06So it seems that because Dindim spent his formative first summer
0:14:06 > 0:14:11with Joao, he now sees that beach as his home.
0:14:11 > 0:14:13Whatever the biological explanation may be,
0:14:13 > 0:14:16the warm fuzzy feeling between
0:14:16 > 0:14:18this penguin and his pal is clearly mutual.
0:14:18 > 0:14:22So Dindim is usually very calm and comfortable and happy around
0:14:22 > 0:14:25Mr Joao, and the opposite is true as well.
0:14:25 > 0:14:27He is in heaven when Dindim is around.
0:14:27 > 0:14:30I would say this is a friendship, why not?
0:14:30 > 0:14:34What better definition for friendship than that?
0:14:34 > 0:14:38Without Joao's help, Dindim surely would have died.
0:14:38 > 0:14:43His kind actions have earned him an unlikely new best friend.
0:14:52 > 0:14:57While Atlantic currents delivered this penguin to a loving new home,
0:14:57 > 0:15:01unusual weather revealed a puzzle in the permafrost.
0:15:04 > 0:15:09Siberia. Where temperatures often fall to minus-40 degrees.
0:15:09 > 0:15:12And the ground is frozen solid year round.
0:15:14 > 0:15:16But in August 2015,
0:15:16 > 0:15:21a freak flood in the Sakha Republic exposed a fresh patch of tundra.
0:15:23 > 0:15:24Scientists working in the area
0:15:24 > 0:15:27stumbled across a weird-looking lump.
0:15:38 > 0:15:41They chipped away at the block of ice...
0:15:41 > 0:15:44Something furry emerged.
0:15:44 > 0:15:48The scientists had uncovered two frozen animals,
0:15:48 > 0:15:49but what could they be?
0:15:53 > 0:15:55Wild dogs?
0:15:55 > 0:15:57Polar bears?
0:15:57 > 0:16:01No, this was something even more extraordinary.
0:16:02 > 0:16:05A couple of very young lion cubs.
0:16:10 > 0:16:11Wait a minute.
0:16:11 > 0:16:16Lions in Siberia, how could that be?
0:16:16 > 0:16:20I mean, we all know that lions roam the plains of Africa here.
0:16:20 > 0:16:25And that there is a small population over here in north-western India.
0:16:25 > 0:16:32But that's still more than 3,000 miles away from Siberia, here.
0:16:32 > 0:16:35So how did those cubs turn up so far from home?
0:16:37 > 0:16:42Well, in fact, the icy Siberian tundra was their home.
0:16:42 > 0:16:45But not for 10,000 years.
0:16:45 > 0:16:49These are baby cave lions, and they've been extinct for millennia.
0:16:51 > 0:16:56Cave lions were around from a little over 300,000 years ago,
0:16:56 > 0:16:58when we first find them in Europe.
0:16:58 > 0:17:02To approximately between 14,000 and 10,000 years ago
0:17:02 > 0:17:05was when they started to disappear from most of the range.
0:17:13 > 0:17:17Cave lions were about 10% bigger than modern African lions
0:17:17 > 0:17:19and roamed most of the Northern Hemisphere,
0:17:19 > 0:17:21from Alaska to eastern Russia.
0:17:24 > 0:17:26After detailed investigation,
0:17:26 > 0:17:28biologists hypothesise that the cub's mother
0:17:28 > 0:17:32left them in a den while she went off hunting.
0:17:32 > 0:17:34And then while she was away,
0:17:34 > 0:17:37a landslide caused the den to collapse,
0:17:37 > 0:17:38and the cubs perished.
0:17:41 > 0:17:46But if these cubs have been dead for over 10,000 years,
0:17:46 > 0:17:48how do they look so good for their age?
0:17:49 > 0:17:53Well, a simple demonstration should make that clear.
0:17:53 > 0:17:55But I warn you, it's not pretty.
0:17:55 > 0:17:57Look away if you're squeamish.
0:17:59 > 0:18:01Left alone at room temperature,
0:18:01 > 0:18:05a chicken decomposes within a week or so.
0:18:05 > 0:18:08Bacteria and maggots make short work of the carcass.
0:18:09 > 0:18:13But if we simulate the Siberian permafrost,
0:18:13 > 0:18:15the chicken is frozen in time.
0:18:16 > 0:18:18It's not just icy temperatures
0:18:18 > 0:18:21that keep the flesh nice and fresh, though.
0:18:23 > 0:18:26A combination of a lack of oxygen and no sunlight
0:18:26 > 0:18:30also meant the cubs were preserved for thousands of years.
0:18:30 > 0:18:34A chance in a million for biologists.
0:18:34 > 0:18:37From a paleontological standpoint, it's a hugely significant find.
0:18:37 > 0:18:42We very rarely get soft tissue preservation of extinct animals.
0:18:42 > 0:18:44Not just the skeleton, but all the soft tissue, you know,
0:18:44 > 0:18:48all the muscles and the brain and the fur.
0:18:48 > 0:18:50It's just amazing.
0:18:52 > 0:18:57And the soft tissue is the final twist in this Siberian story.
0:18:57 > 0:19:01You see, not content with merely uncovering these cubs,
0:19:01 > 0:19:04biologists plan to do the unthinkable.
0:19:06 > 0:19:08To clone the cave lion.
0:19:10 > 0:19:11To bring it back to life.
0:19:12 > 0:19:14But how?
0:19:14 > 0:19:18Well, science has progressed a lot since the first mammal was cloned
0:19:18 > 0:19:20back in 1996.
0:19:22 > 0:19:25'Scientists in Scotland have produced the first-ever clone
0:19:25 > 0:19:26'of an adult animal.
0:19:29 > 0:19:30'Dolly, a seven-month-old sheep,
0:19:30 > 0:19:34'was created in a laboratory using a cell from another sheep.
0:19:34 > 0:19:37'The new step involves taking a cell from an adult sheep
0:19:37 > 0:19:40'and removing the genetic material from it.
0:19:40 > 0:19:44'The genes are then inserted into an empty egg cell taken from another
0:19:44 > 0:19:48'sheep. The egg is then used to start a pregnancy,
0:19:48 > 0:19:50'the offspring being a clone.'
0:19:54 > 0:19:59If intact DNA could be extracted from the cave lions then, in theory,
0:19:59 > 0:20:02they could be brought back from extinction.
0:20:04 > 0:20:08Korean biologist Hwang Woo-suk is taking tissue samples from the cubs.
0:20:23 > 0:20:27Russian and Korean scientists are already working on cloning
0:20:27 > 0:20:29ancient mammoths.
0:20:29 > 0:20:33And as far fetched as this Jurassic dream sounds,
0:20:33 > 0:20:35it might just be possible.
0:20:36 > 0:20:40You see, they don't need pristine DNA to try and bring back
0:20:40 > 0:20:44the cave lion, or, in this case, the mammoth.
0:20:44 > 0:20:48Let's imagine that these parts of this jigsaw represents the good
0:20:48 > 0:20:50mammoth DNA that they have.
0:20:50 > 0:20:54The problem is...they've only got half a mammoth.
0:20:54 > 0:20:59But their plan is to combine it with modern-day elephant DNA,
0:20:59 > 0:21:04and what they end up with is a sort of hybrid embryo,
0:21:04 > 0:21:07not an exact mammoth clone, but, perhaps,
0:21:07 > 0:21:09something pretty close to it.
0:21:11 > 0:21:14Even if scientists manage to create a viable embryo,
0:21:14 > 0:21:16that's just the first step.
0:21:18 > 0:21:20I think what people forget with cloning is that
0:21:20 > 0:21:22you need a host animal.
0:21:22 > 0:21:26And you need many, many replicates in order to get any sort of success.
0:21:26 > 0:21:29So dozens, to potentially hundreds, of surrogate mothers.
0:21:29 > 0:21:32Of course, if you look at modern lion populations,
0:21:32 > 0:21:34they are plummeting. Just in the last few decades,
0:21:34 > 0:21:37the lion populations have been cut almost in half.
0:21:37 > 0:21:42So the amount of resources that would go into cloning the cave lion,
0:21:42 > 0:21:44I think, could be much better spent on saving the lions
0:21:44 > 0:21:46that are around today.
0:21:50 > 0:21:54The possibility of cloning animals like cave lions and mammoths is
0:21:54 > 0:21:56undeniably exciting.
0:21:56 > 0:21:58But it's my duty to tell you that, at the moment,
0:21:58 > 0:22:02a real-life Jurassic Park is still some way off.
0:22:05 > 0:22:10So, whilst El Nino forced starving sea lions inland,
0:22:10 > 0:22:14usual currents carried this Patagonian penguin to Rio.
0:22:15 > 0:22:19And a freak flood gave new life to prehistoric lion cubs.
0:22:22 > 0:22:24When weird weather strikes,
0:22:24 > 0:22:28it can transport animals into some very unlikely places.
0:22:29 > 0:22:30Coming up...
0:22:30 > 0:22:33A selection of superpowers...
0:22:33 > 0:22:36an exceptionally alluring insect...
0:22:36 > 0:22:39and an invader destroying houses in the suburbs.
0:22:41 > 0:22:45But first, we discover how one Scottish woman's
0:22:45 > 0:22:50remarkable sense of smell could change the future of medicine.
0:22:53 > 0:22:55I've always smelt things.
0:22:59 > 0:23:01If I can help it, I don't go in to cake shops,
0:23:01 > 0:23:04it's a smile that I don't particularly like.
0:23:05 > 0:23:08Joy Milne's world is dominated by scent.
0:23:10 > 0:23:12And her exceptionally sensitive nose
0:23:12 > 0:23:14affects the way she perceives people.
0:23:15 > 0:23:18People just don't smell, they have layers of smell.
0:23:18 > 0:23:21They've got a perfume or a spray on,
0:23:21 > 0:23:23but then they've got clothes
0:23:23 > 0:23:25which they have then washed in a fabric softener.
0:23:25 > 0:23:28Then they've got their body smells.
0:23:28 > 0:23:33So, for me, a person has at least two or three different smells.
0:23:33 > 0:23:37To Joy, every person has a distinct odour.
0:23:38 > 0:23:41Including her husband, Les.
0:23:41 > 0:23:45So she noticed straightaway when his scent suddenly changed.
0:23:45 > 0:23:47'Out of the blue,'
0:23:47 > 0:23:52I could smell this very musky,
0:23:52 > 0:23:55very heavy smell on him.
0:23:57 > 0:24:00Joy worked as a nurse, while Les was an anaesthetist.
0:24:00 > 0:24:04She assumed that his unpleasant body odour was down to working long hours
0:24:04 > 0:24:06in theatre.
0:24:06 > 0:24:08I did say to him,
0:24:08 > 0:24:11"I'm sorry, but you're not, you know, washing enough."
0:24:11 > 0:24:13And it became quite a contentious sort of thing,
0:24:13 > 0:24:15because he was showering.
0:24:19 > 0:24:20Over the next few years,
0:24:20 > 0:24:24Joy noticed that Les's musky scent became stronger.
0:24:26 > 0:24:28And he developed other problems.
0:24:31 > 0:24:33Les was a keen sportsman,
0:24:33 > 0:24:37but his coordination began to falter.
0:24:37 > 0:24:40We'd play squash until our late 30s,
0:24:40 > 0:24:43things like he was missing the ball.
0:24:43 > 0:24:45He couldn't keep up in the game,
0:24:45 > 0:24:47because usually he beat me no bother at all.
0:24:56 > 0:24:58Les's personality changed too.
0:25:00 > 0:25:05He was generally known to be an extremely laid-back person.
0:25:06 > 0:25:08He became irritable about things.
0:25:08 > 0:25:11He became aggressive, sometimes.
0:25:11 > 0:25:14It's very strange living with somebody that you've known
0:25:14 > 0:25:19since he was 16, change quite a bit in the gap of ten years.
0:25:20 > 0:25:22So what could be causing these
0:25:22 > 0:25:24worrying mental and physical symptoms?
0:25:26 > 0:25:30Les was eventually diagnosed with Parkinson's disease,
0:25:30 > 0:25:33a progressive disorder of the nervous system,
0:25:33 > 0:25:37but not a condition that had ever before been associated with a change
0:25:37 > 0:25:41in body odour. So could there possibly be a connection here?
0:25:42 > 0:25:45When Joy went to a Parkinson's support group,
0:25:45 > 0:25:48she made a sensational discovery.
0:25:48 > 0:25:52And she couldn't wait to tell her husband.
0:25:52 > 0:25:55I said to him, "These people smell the same as you."
0:26:00 > 0:26:03And he said, "What are you talking about?"
0:26:03 > 0:26:07And I said, "Those people smell exactly the same as you."
0:26:08 > 0:26:14Joy seems to have an extraordinary ability to sniff out Parkinson's.
0:26:15 > 0:26:17As medical professionals,
0:26:17 > 0:26:21Joy and Les realised that this could be ground-breaking.
0:26:21 > 0:26:24There's currently no simple way to diagnose Parkinson's and
0:26:24 > 0:26:27Joy's nose could hold the key to developing a test.
0:26:30 > 0:26:33So Joy approached scientists working on the disease
0:26:33 > 0:26:36and told them about her strange ability.
0:26:36 > 0:26:40Together, we devised a method to try and see if we could understand
0:26:40 > 0:26:42what it was, what the smell was.
0:26:48 > 0:26:51We did a control experiment where we had people suffering from
0:26:51 > 0:26:54Parkinson's, fairly late-stage on, and people who weren't.
0:26:54 > 0:26:56We made them wear T-shirts.
0:26:56 > 0:26:59And we then cut the T-shirts up and put them in bags so that they were
0:26:59 > 0:27:02anonymous and took them to Joy to smell.
0:27:02 > 0:27:05And Joy was extremely good at identifying
0:27:05 > 0:27:07the people who had Parkinson's.
0:27:08 > 0:27:11Joy got all but one sample correct.
0:27:11 > 0:27:14She thought one of the people without Parkinson's, in fact,
0:27:14 > 0:27:15had the disease.
0:27:16 > 0:27:20Perhaps her olfactory powers weren't foolproof after all.
0:27:22 > 0:27:25But then, something incredible happened.
0:27:25 > 0:27:28That person, about a year afterwards,
0:27:28 > 0:27:31was diagnosed with Parkinson's disease.
0:27:31 > 0:27:35Joy had been right all along.
0:27:35 > 0:27:39What is mind-blowing here is that she could detect Parkinson's
0:27:39 > 0:27:41simply using her nose -
0:27:41 > 0:27:43well before any doctor could.
0:27:44 > 0:27:47So what is it that Joy can smell?
0:27:49 > 0:27:51It's all down to sebum.
0:27:51 > 0:27:54That oily substance that coats our skin.
0:27:54 > 0:27:57It's made up of thousands of different ingredients.
0:27:58 > 0:28:03We identified approximately 9,000 unique molecules.
0:28:03 > 0:28:08What we need to now do is to find out what the differences are between
0:28:08 > 0:28:11a healthy person and someone with Parkinson's.
0:28:11 > 0:28:15Once the team have identified which chemicals cause the distinctive
0:28:15 > 0:28:21Parkinson's smell, they can develop a test to find those compounds
0:28:21 > 0:28:23rather than relying on Joy's nose.
0:28:23 > 0:28:26We'll be able to diagnose this disease at an early stage,
0:28:26 > 0:28:29before some of the devastating symptoms have started.
0:28:29 > 0:28:35And an early diagnosis is crucial to managing this condition effectively.
0:28:35 > 0:28:38But there's something even more exciting.
0:28:38 > 0:28:40The smell that Joy first discovered
0:28:40 > 0:28:44could also help develop new medicines.
0:28:44 > 0:28:45'Because it happens so early,'
0:28:45 > 0:28:49because there's a change so early on in the start of the disease,
0:28:49 > 0:28:53it may tell us something really crucial about the beginning stage of
0:28:53 > 0:28:56the disease, which will open the door to new treatments and a better
0:28:56 > 0:28:58understanding of how it progresses.
0:29:00 > 0:29:03Sadly, Les died in 2015.
0:29:05 > 0:29:09But Joy is determined to use her finely-tuned sense of smell to help
0:29:09 > 0:29:14others and raise awareness of the early symptoms of Parkinson's.
0:29:14 > 0:29:17You're given what you're given in life.
0:29:18 > 0:29:22I've had this smell, I've married this person,
0:29:22 > 0:29:24they've then got Parkinson's.
0:29:24 > 0:29:26And I've lived through it.
0:29:26 > 0:29:32I don't want other people to have that, that problem.
0:29:32 > 0:29:34It's horrendous. It is.
0:29:34 > 0:29:37It really is. And I want that early diagnosis.
0:29:39 > 0:29:43Joy's fortitude through such difficult times
0:29:43 > 0:29:44is incredible in itself.
0:29:44 > 0:29:49But the fact that she noticed a change in her husband's smell
0:29:49 > 0:29:51and related it directly to his disease
0:29:51 > 0:29:55could lead to massive leaps forward in medical science.
0:29:55 > 0:30:00You know, sometimes it's just the quirky little things in biology -
0:30:00 > 0:30:03in this case, an extraordinary sense of smell -
0:30:03 > 0:30:05which leads to such rapid progress.
0:30:11 > 0:30:16Whilst Joy's super-sense could help fight Parkinson's disease,
0:30:16 > 0:30:21our next weird tale features an animal with a super-secret weapon.
0:30:23 > 0:30:26The remote Zagros Mountains in western Iran -
0:30:26 > 0:30:30home to an animal found nowhere else on earth.
0:30:32 > 0:30:35A strange spiderlike creature.
0:30:43 > 0:30:46It's the height of the breeding season,
0:30:46 > 0:30:49and birds are desperately trying to find enough food
0:30:49 > 0:30:50for their growing chicks.
0:30:52 > 0:30:55So this looks like a perfect, juicy meal.
0:31:03 > 0:31:08But on this occasion, it's the bird that becomes dinner,
0:31:08 > 0:31:10for a perfectly camouflaged viper.
0:31:12 > 0:31:16And it looks like the snake is joining forces
0:31:16 > 0:31:17with the creepy-crawly.
0:31:18 > 0:31:21That is astonishing.
0:31:21 > 0:31:23What is that weird spider thing?
0:31:23 > 0:31:25What is it doing?
0:31:25 > 0:31:28Could it really be helping the snake to catch its prey?
0:31:28 > 0:31:30Well, in a sense, it is.
0:31:30 > 0:31:34But the truth is much, much more bizarre than that.
0:31:34 > 0:31:36Have a closer look.
0:31:41 > 0:31:46Look, that creepy-crawly appears to be clinging on to the snake's tail.
0:31:48 > 0:31:52Reptile expert Steven Anderson was mystified when
0:31:52 > 0:31:55he first saw a specimen in the Chicago Field Museum
0:31:55 > 0:31:57over 40 years ago.
0:31:57 > 0:32:01I was there to identify a collection of reptiles from Iran.
0:32:05 > 0:32:06I happened to open a bottle.
0:32:06 > 0:32:08I pulled the snake out and looked at it,
0:32:08 > 0:32:12and I didn't know what to think of it at that point.
0:32:12 > 0:32:15On closer inspection, Steven got a shock.
0:32:15 > 0:32:19I was very startled to see that it was actually an ornamentation
0:32:19 > 0:32:21of the tail itself.
0:32:23 > 0:32:28Yes, this thing was actually part of the snake.
0:32:28 > 0:32:30But what was it?
0:32:30 > 0:32:33With just a single preserved specimen,
0:32:33 > 0:32:36it was impossible to work out whether it was just
0:32:36 > 0:32:40a ghoulish anomaly or a whole new species.
0:32:44 > 0:32:47For four decades, the mystery remained unsolved.
0:32:48 > 0:32:53Until, in 2014, when the snake was filmed in the wild.
0:32:53 > 0:32:57And the truth was finally revealed.
0:33:07 > 0:33:10That strange structure is a lure,
0:33:10 > 0:33:13used to entice prey.
0:33:13 > 0:33:16It moves its tail back and forth along the ground,
0:33:16 > 0:33:19and because of the strange appendage,
0:33:19 > 0:33:24these elongated scales look like legs when it moves,
0:33:24 > 0:33:26like a spider moving around.
0:33:26 > 0:33:29And the end of the tail, the last two scales,
0:33:29 > 0:33:32form what looks like the body of this creature.
0:33:32 > 0:33:35This one seems to be very attractive to birds.
0:33:37 > 0:33:40This surreal snake was new to science,
0:33:40 > 0:33:42and imaginatively named...
0:33:44 > 0:33:47..the spider-tailed pit viper.
0:33:52 > 0:33:55Other animals use a similar strategy.
0:33:55 > 0:34:00A humpbacked anglerfish attracts prey with its built-in fishing rod.
0:34:02 > 0:34:07And this turtle's wormlike tongue fascinates its unsuspecting victim.
0:34:08 > 0:34:11It's a very useful trick.
0:34:11 > 0:34:16Just sit still and tempt your dinner to within striking distance.
0:34:20 > 0:34:25And the viper attacks within two-tenths of a second.
0:34:30 > 0:34:33Then it just waits for its venom to take effect.
0:34:34 > 0:34:41That tantalising tail is THE most elaborate lure in the reptile world.
0:34:48 > 0:34:51That is one sneaky snake.
0:34:51 > 0:34:55And whilst I recognise that a snake with a tail like a spider
0:34:55 > 0:34:58is the stuff of nightmares to many people,
0:34:58 > 0:35:02for me, this thing is a triumph of evolution.
0:35:02 > 0:35:03It's remarkable.
0:35:05 > 0:35:10From a predator that hides in plain sight, we now travel to Florida,
0:35:10 > 0:35:13where intruders are lurking in the undergrowth.
0:35:15 > 0:35:17Miami.
0:35:17 > 0:35:20Glamorous. Cool.
0:35:20 > 0:35:22Playground of the rich and beautiful.
0:35:24 > 0:35:28But a recent invasion is distressing local residents.
0:35:30 > 0:35:33Oh, my God. I will never go out.
0:35:33 > 0:35:35I will not let my kids go outside and play.
0:35:36 > 0:35:39We didn't know what they were in the beginning.
0:35:39 > 0:35:42They would start climbing up the trees and just seemed to stay there.
0:35:42 > 0:35:44We began to see...hundreds.
0:35:45 > 0:35:48Properties are being overrun by alien creatures.
0:35:48 > 0:35:51I found one the size of my hand.
0:35:51 > 0:35:54So what's the cause of all of this anxiety?
0:35:55 > 0:35:57They are big. There are slimy
0:35:57 > 0:36:00and a lot of people think they're downright disgusting.
0:36:00 > 0:36:01Snails.
0:36:01 > 0:36:03Large snails.
0:36:03 > 0:36:04They're everywhere.
0:36:06 > 0:36:07I know what you're thinking,
0:36:07 > 0:36:10have the residents of Miami gone completely crazy?
0:36:10 > 0:36:14I mean, every garden has slugs and snails, doesn't it?
0:36:14 > 0:36:18Well, it might. But not snails like this one.
0:36:18 > 0:36:20You see, this is a giant African land snail.
0:36:20 > 0:36:23They can grow to up to 20 centimetres.
0:36:23 > 0:36:25They can live for up to nine years.
0:36:25 > 0:36:27These are monster snails.
0:36:30 > 0:36:32And they are causing panic because
0:36:32 > 0:36:35they don't just munch on a few garden plants.
0:36:37 > 0:36:40They'll eat over 500 different crops.
0:36:42 > 0:36:45They'll even devour people's homes.
0:36:47 > 0:36:49Yes, really.
0:36:49 > 0:36:50They're eating the concrete.
0:36:50 > 0:36:53Because they're getting calcium out of that to help build
0:36:53 > 0:36:55their shells stronger and bigger.
0:37:01 > 0:37:04But what's most worrying is that in Florida,
0:37:04 > 0:37:07they may carry a type of meningitis
0:37:07 > 0:37:12that can be passed on to humans via their slime.
0:37:12 > 0:37:16So these snails are a menace to human health and to the economy.
0:37:16 > 0:37:19But where have they all come from?
0:37:19 > 0:37:22Well, they are native to Africa.
0:37:22 > 0:37:25No-one is completely sure how they first came to Florida,
0:37:25 > 0:37:29but people have been caught smuggling them into the country.
0:37:32 > 0:37:34A lady coming back from Nigeria last year
0:37:34 > 0:37:36had 12 of them hidden under her dress.
0:37:36 > 0:37:38A man coming back from the Philippines,
0:37:38 > 0:37:42and he had one giant African snail in each one of his suit pockets.
0:37:42 > 0:37:43However they arrived,
0:37:43 > 0:37:48with plenty of lush vegetation and no natural predators,
0:37:48 > 0:37:50the invading snail population has boomed.
0:37:53 > 0:37:55Meet Harry the snail.
0:37:55 > 0:37:56Or maybe Harriet the snail,
0:37:56 > 0:37:59You see, it's difficult to ascribe a name to a snail,
0:37:59 > 0:38:01because they are hermaphrodite.
0:38:01 > 0:38:05They have both male and female reproductive apparatus.
0:38:05 > 0:38:07This is a real benefit to them.
0:38:07 > 0:38:10They don't have to go through that rigmarole of finding and then
0:38:10 > 0:38:14charming a mate. They can simply get on with reproduction.
0:38:14 > 0:38:18And they do. They can produce up to 1,000 eggs a year.
0:38:18 > 0:38:20I mean, you do the maths.
0:38:20 > 0:38:22These things are unstoppable.
0:38:24 > 0:38:28So the risk of disease and downright destruction
0:38:28 > 0:38:31means that local authorities are under pressure
0:38:31 > 0:38:33to eradicate these slimy intruders.
0:38:37 > 0:38:40We created a giant African land snail incident command.
0:38:42 > 0:38:46We're doing a lot of outreach in schools, at events,
0:38:46 > 0:38:47we do billboards,
0:38:47 > 0:38:49radio ads and television ads.
0:38:52 > 0:38:56The authorities rely on people ringing in with their sightings.
0:38:56 > 0:38:59I started seeing signs on the back of trucks which said,
0:38:59 > 0:39:01"Call the state of Florida."
0:39:01 > 0:39:03As soon as I saw this meningitis...
0:39:04 > 0:39:06..that scared me to death.
0:39:10 > 0:39:12They came several times a week,
0:39:12 > 0:39:15and they would pick up hundreds of them and put them in plastic bags.
0:39:15 > 0:39:17And, you know, take them away.
0:39:19 > 0:39:24The snail squad seem to be getting on top of the slow-mo swarm.
0:39:24 > 0:39:28We've collected over 162,000 giant African land snails.
0:39:28 > 0:39:32The idea is get the population down. And we've accomplished that.
0:39:32 > 0:39:36But if these snails can lay 100 eggs at a time,
0:39:36 > 0:39:38to get on top of the problem,
0:39:38 > 0:39:43the authorities are going to need to find every single last one of them.
0:39:44 > 0:39:49And until recently, that's been an almost impossible task.
0:39:49 > 0:39:52But now, the authorities have a secret weapon.
0:39:55 > 0:39:57Meet Sierra.
0:39:57 > 0:39:59Come on, let's go.
0:39:59 > 0:40:04We use canines because they can get to places where humans can't.
0:40:07 > 0:40:11They can smell that snail and go after it and alert us that there are
0:40:11 > 0:40:14giant African snails there.
0:40:14 > 0:40:15Yeah! Good girl, babe.
0:40:15 > 0:40:17You found it.
0:40:17 > 0:40:19Good girl.
0:40:19 > 0:40:20Good girl.
0:40:20 > 0:40:25In Shannon's garden, the snail squad's efforts seem to be working.
0:40:25 > 0:40:29It's been amazingly successful because for months,
0:40:29 > 0:40:31I have not seen a snail.
0:40:31 > 0:40:34But Mark and his team must remain vigilant.
0:40:36 > 0:40:39Just the other day we found a 4.8 incher, which is an adult,
0:40:39 > 0:40:44which means that there are children, or neonates
0:40:44 > 0:40:47that are out there in the wild. We have to keep looking for them.
0:40:53 > 0:40:55So the snail squad's efforts
0:40:55 > 0:40:58and their search for these marauding molluscs
0:40:58 > 0:41:00is set to continue.
0:41:00 > 0:41:04And Sierra's sniffing services are going to be needed for a while yet.
0:41:12 > 0:41:17From a super-sensitive nose that can sniff out Parkinson's disease
0:41:17 > 0:41:19and a snake with a hidden weapon...
0:41:21 > 0:41:24..to a super-sized house-eating snail,
0:41:24 > 0:41:27there's no doubt that nature's superpowers
0:41:27 > 0:41:31can lead to some truly bizarre consequences.
0:41:34 > 0:41:36Coming up...
0:41:36 > 0:41:37A strange glowing slime.
0:41:39 > 0:41:42And alien objects that fell from the sky.
0:41:45 > 0:41:50But first, we head to the holiday resort of Fethiye
0:41:50 > 0:41:52on the Turkish coast.
0:41:54 > 0:41:56On the 9th of July 2015,
0:41:56 > 0:42:00dive instructor Lutfu Tanriover jumped into the
0:42:00 > 0:42:03calm blue waters of the Mediterranean,
0:42:03 > 0:42:07something he'd done hundreds of times before.
0:42:07 > 0:42:11I have been diving the area for eight years.
0:42:11 > 0:42:14And at least once a week we are going to that dive site.
0:42:18 > 0:42:21Little did he know what he'd find under the waves this time.
0:42:26 > 0:42:30A blob of baffling proportions.
0:42:30 > 0:42:33It was three, four metres wide.
0:42:33 > 0:42:37And drifting about 22 metres in the middle of the water.
0:42:37 > 0:42:39It was a very, very big bubble.
0:42:42 > 0:42:47We were all fascinated by it because nobody had ever seen
0:42:47 > 0:42:49something like that before.
0:42:49 > 0:42:50I decided to call it The Thing.
0:42:52 > 0:42:56Lutfu posted this footage of The Thing online,
0:42:56 > 0:43:00where it grabbed the attention of marine biologist Steve Haddock.
0:43:01 > 0:43:04So what did he think this bewildering blob could be?
0:43:06 > 0:43:08When you see something like that,
0:43:08 > 0:43:11there's only a few things that it might potentially be.
0:43:11 > 0:43:13One of the things is a pyrosome.
0:43:17 > 0:43:21This is a colony of organisms that can form
0:43:21 > 0:43:24either a small tube or, actually, one species can form very,
0:43:24 > 0:43:27very large tubes that divers can actually swim inside of.
0:43:27 > 0:43:30But the thing that Lutfu filmed was a ball.
0:43:30 > 0:43:32Not a tube.
0:43:32 > 0:43:35So if it wasn't a colony of individual creatures,
0:43:35 > 0:43:38what was this awe-inspiring orb?
0:43:38 > 0:43:40And where had it come from?
0:43:42 > 0:43:46The secret to the blob's source lay inside the sphere.
0:43:46 > 0:43:48You see, initially, it looked translucent.
0:43:48 > 0:43:53See-through. But then, under closer inspection,
0:43:53 > 0:43:56Lutfu could see something inside.
0:43:59 > 0:44:03When you go next to it, we put the torches in it,
0:44:03 > 0:44:07and then we saw with the torches, we have seen so many particles in it.
0:44:09 > 0:44:13These particles provided a vital clue.
0:44:13 > 0:44:17You see, this isn't a single giant blob at all.
0:44:17 > 0:44:21But millions of tiny individual spheres.
0:44:21 > 0:44:22Squid eggs.
0:44:22 > 0:44:24Instead of having them individually,
0:44:24 > 0:44:27they're like little snacks for other organisms to live on,
0:44:27 > 0:44:31they embed them in a giant gelatinous mass.
0:44:31 > 0:44:36It's a strategy that certain species of squid use in the open ocean
0:44:36 > 0:44:39where there are lots of hungry mouths around.
0:44:39 > 0:44:41Predators could come from any direction,
0:44:41 > 0:44:44and you have very few ways to hide or secure your eggs.
0:44:44 > 0:44:46But if you put them in this mass,
0:44:46 > 0:44:48it's large enough, it excludes all the predators
0:44:48 > 0:44:50that are smaller than that.
0:44:54 > 0:44:59This enormous egg mass is the squid's way of maximising
0:44:59 > 0:45:01its offspring's chances of survival.
0:45:01 > 0:45:04Blobs like this are rarely seen,
0:45:04 > 0:45:07they last just a few days before breaking up.
0:45:07 > 0:45:10Then each baby squid will face the world alone.
0:45:13 > 0:45:16But there's one puzzle left.
0:45:17 > 0:45:22So how does a relatively small squid produce something so huge?
0:45:22 > 0:45:26Well, its eggs start off quite small.
0:45:26 > 0:45:31But they expand massively in sea water.
0:45:31 > 0:45:34It's a bit like frog spawn on steroids.
0:45:38 > 0:45:43So this vast blob of jelly is the secret to a squid's success.
0:45:43 > 0:45:46Protecting its precious eggs from predators.
0:45:50 > 0:45:52Whilst this bizarre ball appeared underwater...
0:45:54 > 0:45:57..our next mystery was spotted underground.
0:46:00 > 0:46:02In March 2016,
0:46:02 > 0:46:06Anthony Roberts was exploring this old slate mine in North Wales.
0:46:08 > 0:46:12Scoping out new areas for guided tours.
0:46:12 > 0:46:14His normal route in and out was flooded,
0:46:14 > 0:46:17so he used the emergency exit tunnels instead.
0:46:19 > 0:46:23On the way out, something stopped him in his tracks.
0:46:28 > 0:46:33A very strange, very bright luminous green material.
0:46:35 > 0:46:37It kept glowing.
0:46:43 > 0:46:48This glimmering stuff has been found in dark nooks and crannies
0:46:48 > 0:46:49around the globe.
0:46:51 > 0:46:53'Wow!'
0:46:53 > 0:46:54In Cornwall...
0:46:58 > 0:46:59Germany...
0:47:00 > 0:47:03- 'Holy- BLEEP, - look at that down there.
0:47:03 > 0:47:05'It is, it's glowing.'
0:47:05 > 0:47:07And even New York state.
0:47:09 > 0:47:13So what on earth could be producing this eerie green glow?
0:47:13 > 0:47:16Well, some rocks have the ability to fluoresce,
0:47:16 > 0:47:19the minerals within them can absorb light and then re-emit it.
0:47:19 > 0:47:22Like glow-in-the-dark stickers.
0:47:23 > 0:47:28True, but could this glowing green goo actually be alive?
0:47:31 > 0:47:35In Africa, there is a fungus that lights up the forest floor.
0:47:36 > 0:47:40It uses the luminous enzymes to breakdown leaf litter.
0:47:40 > 0:47:43The locals call it chimpanzee fire.
0:47:44 > 0:47:49But there was something completely unfathomable about the green goo
0:47:49 > 0:47:52that Anthony found in Wales.
0:47:52 > 0:47:57It had the disturbing ability to vanish before his eyes.
0:47:57 > 0:47:59It wasn't until I
0:47:59 > 0:48:01took a few steps closer,
0:48:01 > 0:48:05looked back at it from a slightly different direction and realised
0:48:05 > 0:48:07it's completely disappeared.
0:48:07 > 0:48:10I couldn't see it at all.
0:48:10 > 0:48:14So what was this glistening substance that glowed one moment
0:48:14 > 0:48:15and was gone the next?
0:48:18 > 0:48:23In the past, people believed it was the treasure of goblins.
0:48:23 > 0:48:24Probably hundreds of years,
0:48:24 > 0:48:28the stories about goblins hiding their gold in caves
0:48:28 > 0:48:30and all sorts of dark places.
0:48:32 > 0:48:37People walking past dark caves and such places see this glow of
0:48:37 > 0:48:40emeralds in the back and they go in and say,
0:48:40 > 0:48:42"This is the treasure, we're going to go in..."
0:48:42 > 0:48:45And you go in and grab a bit and you come out, and of course,
0:48:45 > 0:48:47it's not there. It's completely gone.
0:48:47 > 0:48:50So, obviously, it's goblins, what else could it be?
0:48:52 > 0:48:57In fact, these aren't sparkling gems hidden by mythical creatures.
0:48:57 > 0:48:59But the answer is almost as magical.
0:49:01 > 0:49:03It's a very clever trick by a moss
0:49:03 > 0:49:07that lives in these special circumstances.
0:49:07 > 0:49:10A moss called goblin gold.
0:49:10 > 0:49:13But this is no ordinary moss.
0:49:13 > 0:49:17It's developed some very special cells that allow it to live
0:49:17 > 0:49:20where there's almost no light.
0:49:20 > 0:49:21So how does it work?
0:49:24 > 0:49:28The front of each cell is curved like a lens,
0:49:28 > 0:49:32this focuses light rays and boosts the amount of light reaching the
0:49:32 > 0:49:35chloroplasts - those parts of the plant that produce energy
0:49:35 > 0:49:37through photosynthesis.
0:49:37 > 0:49:42The reason it glows is that some of the light is reflected back out
0:49:42 > 0:49:44through that lens.
0:49:44 > 0:49:48And this is the key to the moss's mysterious disappearance.
0:49:49 > 0:49:54Those reflected light rays can only be seen from one particular angle.
0:49:57 > 0:50:02And Anthony happened to stop in just the right place.
0:50:02 > 0:50:04If I'd been one step higher or one step lower,
0:50:04 > 0:50:06I wouldn't have noticed it.
0:50:10 > 0:50:12Imagine that.
0:50:12 > 0:50:15Lurking out there in the dark, all across the UK,
0:50:15 > 0:50:19there's green gold just waiting to be discovered.
0:50:19 > 0:50:20Fantastic.
0:50:22 > 0:50:26For our final dose of weirdness, we head to southern Spain.
0:50:32 > 0:50:35Normally, Calasparra is a small, sleepy town.
0:50:40 > 0:50:46But in November 2015, a local farmer found something out of this world.
0:50:49 > 0:50:52A peculiar, alien object appeared out of nowhere.
0:50:58 > 0:51:01I saw a black ball about 60 centimetres across
0:51:01 > 0:51:03lying close to the bottom of the bank,
0:51:03 > 0:51:06and a big dent where it hit the ground.
0:51:11 > 0:51:14When I saw it, I called the police straightaway.
0:51:14 > 0:51:16They told me not to touch it.
0:51:18 > 0:51:21The police cautiously collected the huge hairy ball
0:51:21 > 0:51:23and took it away for analysis.
0:51:25 > 0:51:27And this wasn't a one-off.
0:51:27 > 0:51:32That month, two more of these eerie orbs turned up in the region.
0:51:34 > 0:51:38And around the globe, there were reports of more weird objects
0:51:38 > 0:51:42suddenly appearing. These odd balls turned up in Vietnam.
0:51:45 > 0:51:47Another was discovered in Brazil.
0:51:48 > 0:51:50But where had they all come from?
0:51:53 > 0:51:55Back in Spain, there was a clue.
0:52:00 > 0:52:03Witnesses in the town said they saw strange objects,
0:52:03 > 0:52:06like a cluster of fire, which then dispersed and fell.
0:52:12 > 0:52:16They told me there were between four and six unidentified flying objects.
0:52:16 > 0:52:19Burning UFOs falling from space.
0:52:19 > 0:52:23Understandably, the mayor was very concerned.
0:52:24 > 0:52:28We were worried that it might happen again, falling on a primary school,
0:52:28 > 0:52:30someone's home, or a playground.
0:52:32 > 0:52:36So what could explain these menacing missiles that tumbled to Earth?
0:52:38 > 0:52:39Whoa!
0:52:40 > 0:52:45Well, our skies are the scene of some strange sights.
0:52:45 > 0:52:49One possibility is that they were some sort of mysterious meteorite.
0:52:50 > 0:52:54This one caused confusion when it landed in Kenya.
0:52:54 > 0:52:57'Residents of the Ol Donyo Sabuk area hear a loud noise
0:52:57 > 0:53:00'from the sky above. But there's no aircraft in sight.
0:53:00 > 0:53:04'Instead, a strange object, whose appearance left many puzzled.'
0:53:04 > 0:53:08And, you know, falling meteors are more common than you might think.
0:53:10 > 0:53:14Every day, the Earth is bombarded with thousands of pieces of rock
0:53:14 > 0:53:16that come from outer space.
0:53:16 > 0:53:18Now, as they enter the atmosphere,
0:53:18 > 0:53:22a tremendous friction is generated and they burst into flames.
0:53:22 > 0:53:26But if they survive that re-entry, then they become meteorites.
0:53:26 > 0:53:30Irregularly shaped, really heavy pieces of rock.
0:53:36 > 0:53:39But these space balls clearly weren't made of stone.
0:53:43 > 0:53:47So if they weren't meteorites, what were these alien orbs?
0:53:51 > 0:53:54At first, the scientist tasked with analysing the space balls was
0:53:54 > 0:53:57absolutely flummoxed.
0:53:57 > 0:54:00What a strange artefact. What a strange object.
0:54:00 > 0:54:04I've never seen anything
0:54:04 > 0:54:05similar before.
0:54:08 > 0:54:11Juan Antonio tested every bit of the ball.
0:54:13 > 0:54:15We found out
0:54:15 > 0:54:20the cover of the balls was made of carbon fibre.
0:54:20 > 0:54:22We discovered that
0:54:22 > 0:54:29some parts of the balls were made of a special stainless steel,
0:54:29 > 0:54:31and the metal of the main body
0:54:31 > 0:54:34was made of titanium.
0:54:35 > 0:54:37Right, so let's just get this straight.
0:54:37 > 0:54:40Fireballs, made of carbon fibre and titanium,
0:54:40 > 0:54:43are battering us from beyond our planet?
0:54:43 > 0:54:47So are these cannonballs a sign of intelligent life?
0:54:47 > 0:54:49Well, yes.
0:54:59 > 0:55:04You see, they are from outer space, but we put them there.
0:55:06 > 0:55:09These balls are fuel tanks, yes.
0:55:09 > 0:55:12Fuel tanks for powering rockets.
0:55:12 > 0:55:15'One small step for man.
0:55:15 > 0:55:18'One giant leap for mankind.'
0:55:18 > 0:55:22Since we began exploring space in the 1960s,
0:55:22 > 0:55:25nearly 7,000 satellites have been sent into orbit.
0:55:28 > 0:55:30And the metal balls found in Calasparra,
0:55:30 > 0:55:32Vietnam and Brazil
0:55:32 > 0:55:35are the remains of the small fuel tanks that are used
0:55:35 > 0:55:40to manoeuvre them. So, if they're supposed to be up in space,
0:55:40 > 0:55:43how did these fuel tanks end up in Spain?
0:55:44 > 0:55:48Well, sometimes satellites may break down or collide
0:55:48 > 0:55:51and the debris can fall back to Earth,
0:55:51 > 0:55:53or de-orbit.
0:55:53 > 0:55:55In a given month, 10 or 20 objects will de-orbit,
0:55:55 > 0:55:58that means they'll burn up in the atmosphere.
0:56:01 > 0:56:04When we have control over a de-orbit, we nearly always aim for the
0:56:04 > 0:56:08middle of the Pacific Ocean because it's a very big, uninhabited area.
0:56:08 > 0:56:10The problem is, when certain larger bits of debris de-orbit,
0:56:10 > 0:56:12larger pieces, fuel tanks etc,
0:56:12 > 0:56:14we have no control over where they'll land.
0:56:14 > 0:56:18We really won't know until very late in the de-orbit process.
0:56:21 > 0:56:23Whilst most debris burns up,
0:56:23 > 0:56:27robust parts like fuel tanks may survive re-entry.
0:56:27 > 0:56:32Realistically, space junk poses little risk of injury.
0:56:32 > 0:56:36It's much more dangerous hurtling around our planet.
0:56:36 > 0:56:39A paint fleck will have the same kinetic energy as a rifle bullet,
0:56:39 > 0:56:42and poses a real danger to spacecraft and asteroids.
0:56:44 > 0:56:48There are now millions of bits of debris circling the Earth.
0:56:48 > 0:56:50Some as big as a bus.
0:56:50 > 0:56:53And any collisions with the satellites we rely upon
0:56:53 > 0:56:56could jeopardise our whole way of life.
0:56:56 > 0:56:59The internet may go down because we rely on space-based communications
0:56:59 > 0:57:02more than ever in our connected society.
0:57:02 > 0:57:04A lot of the banking industry and finance industry relies on
0:57:04 > 0:57:07very accurate timing for high-frequency trading.
0:57:07 > 0:57:10If we lost those timing signals, there could be financial chaos.
0:57:12 > 0:57:16But don't worry, a global meltdown is highly unlikely.
0:57:16 > 0:57:19Space debris is very carefully monitored so that satellites
0:57:19 > 0:57:22can be moved out of harm's way.
0:57:23 > 0:57:27So, those strange Spanish balls weren't a sign of an alien attack.
0:57:28 > 0:57:33They were a symbol of the ever-increasing mass of space junk
0:57:33 > 0:57:34that's circling our planet.
0:57:36 > 0:57:40So, while Spain fell under attack by balls from space...
0:57:42 > 0:57:45..an equally strange sphere was found underwater...
0:57:47 > 0:57:49..and a mythical moss was uncovered underground.
0:57:53 > 0:57:57So there. Just goes to prove that although the weird and the wonderful
0:57:57 > 0:58:00can turn up in every corner of the globe,
0:58:00 > 0:58:04the extraordinary is just as likely to appear on your doorstep.
0:58:07 > 0:58:11Next time, we uncover some incredible creatures...
0:58:11 > 0:58:14I had trouble breathing. I started to get chest pains.
0:58:14 > 0:58:16I've never felt anything like that before.
0:58:16 > 0:58:19..reveal some seriously spooky spectres...
0:58:19 > 0:58:21It comes and goes.
0:58:21 > 0:58:23It can be there for a second and then be gone.
0:58:24 > 0:58:28..and find out why albatross chicks are planted in pots.