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00:102017 was a busy year for scientists of all sorts, the professional and the
00:17enthusiast alike. From a predictable astronomical rarity to surprise
00:25discoveries deep underground, it was a year that saw long-held beliefs challenged
00:32by newly found wonders, breakthroughs that led to innovations, and a glimpse 130
00:43million years into the past. In August 2017, alarms sounded at the most
00:52sensitive scientific devices ever constructed. In Washington state, the Laser
01:00Interferometer Gravitational Wave Observatory, LIGO, detected faint
01:05disturbances from deep space. The signal also hit LIGO's sister facility in
01:11Louisiana. Gravitational waves had reached Earth. Gravitational waves are ripples in
01:21space-time. Space-time is incredibly dense. So to cause ripples, you have to have some
01:26sort of object that has enormous gravity, like a black hole or a neutron star. And
01:33when these objects are rapidly accelerating, they bend space-time and
01:37create these ripples that then travel through the universe to our detectors on
01:41Earth, like the one last August. On high alert, the LIGO team quickly reached out to
01:47Virgo, its European counterpart in Italy, who confirmed that they too had detected
01:53gravitational waves. And then, as if by destiny, the stars would align once more to
02:00pave the way to a groundbreaking discovery.
02:04Just two seconds later, with the Fermi Gamma-ray Space Telescope, we detected a short, bright flash
02:12of high-energy light that we call a gamma-ray burst. This alerted the entire astronomical community
02:18to the fact that something very exciting was happening. Using data collected from LIGO, Virgo,
02:25and Fermi, 70 ground and space-based telescopes, scoured the edge of galaxy NGC 4993, some 130 million light-years
02:36away from Earth,
02:37searching for a small flash of light amidst a sea of stars. It would take less than 12 hours after
02:45the alarms rang at LIGO
02:47for Earth to have visual confirmation of a never-before-seen astronomical event.
02:54What we saw was the result of the merging of two neutron stars. When they merged, they created an explosion
03:02in space-time.
03:03Those ripples went out across the universe as gravitational waves and were detected on Earth. The matter involved gave off
03:12gamma rays and other forms of light.
03:15Neutron stars are the collapsed cores of massive stars left behind after a supernova explosion.
03:23No larger than a mid-sized city, these dense stars have 10 to 60 percent more mass than our Sun.
03:32This pair of stars, 200 miles apart, were locked in each other's orbit for over 11 billion years.
03:41But as they started accelerating and moving inwards, their orbit quickened from 30 times a second to an astonishing and
03:49unsustainable 2,000 orbits a second.
03:54Then, 130 million years ago, they collided in a resounding explosion.
04:02Peering into the past, telescopes were able to see the remnants of one of the universe's most impressive fireworks shows.
04:09A bright flash of blue followed the initial explosion, growing redder and duller as the days passed, until eventually fading
04:20to black.
04:23The conditions around these merging neutron stars have densities and temperatures completely unlike anything we can do on Earth.
04:33The violent explosion was observed to have produced 200 Earth masses worth of gold and 500 Earth masses of platinum,
04:43revealing for the first time the origins of heavy metals in our galaxy.
04:50We think that all the gold in the universe was formed in explosions of this kind.
04:54After the explosion happens, the gold is spread out into the gas and dust of the interstellar medium.
05:01Later on, that gas and dust collapses into brand new stars and brand new planetary systems.
05:07And these weren't the first gravitational waves detected by LIGO this year.
05:12Two separate events have been measured before, including a pair of monstrous black holes that collided to form a single
05:19spinning hole 53 times more massive than the sun.
05:24We received a perfect signal from this last merger.
05:27It traveled 3 billion light years to get here.
05:31In any given galaxy, one of these events might only happen once every million years.
05:35But we're now able to monitor about 10 million galaxies at a time.
05:40It's a new type of astronomy.
05:48But while we wait for gravitational waves that can open a window on the origins of our universe,
05:57Volcanic activity off the coast of Japan is presenting scientists with a picture of Earth's early history when land first
06:05rose from the seas.
06:10Violent eruptions spew a steady stream of lava and rocks, expanding the newly emerged island of Nishinoshima three square kilometers
06:21in just five short months this year.
06:25These most recent blasts stopped in August, but could resume at any time.
06:32Situated atop the junction of four tectonic plates, the Japanese islands offer stunning insights about the formation of a variety
06:41of landscapes.
06:51Analysis of Nishinoshima's magma shows it to be andesitic, similar to the composition of continental crust.
07:03Monitoring the growth of Nishinoshima, geologists hope to learn more about the forces that led to the birth of the
07:09world's eight continents.
07:12Yes, not seven. Eight.
07:18In February 2017, the Geological Society of America published a startling paper.
07:25Zealandia, Earth's Hidden Continent.
07:29Geologist Nick Mortimer was the lead author.
07:32To discover Zealandia is to change the map of the world, quite literally.
07:37Beforehand, most people would say, yes, we've got seven continents, they could count them off.
07:42But now, the world maps change and we've got an eighth one on there.
07:47In the beginning, there was no search for Zealandia.
07:51Mortimer and his team discovered the shallow, submerged continent while performing geological work aboard a research vessel off of New
07:58Zealand's coast.
07:59And so, what the various geological investigations have led us to is that we do have the components of a
08:07continent here.
08:08When you pull the plug on the world's oceans, you literally reveal the continent of Zealandia.
08:14Mortimer and his team confirmed four geological markers, the qualifying criteria for a continent.
08:20Height, a varied geology or diversity of rock types, a thick crust, and, ultimately, size.
08:31Is it big enough?
08:34Corroborating data include rock samples, ocean drill cores, and satellite microgravity measurements,
08:42translated into bathymetric or elevation maps of the seafloor.
08:49Situated between the Pacific plate and the Australian plate, tectonic forces squeezed Zealandia,
08:56raising out of the water what we know today as New Zealand.
09:06With 94% of Zealandia underwater, the islands of New Zealand and New Caledonia
09:13are just the tip of this continental iceberg.
09:17And measuring in at 4.9 million square kilometers,
09:22Zealandia is six times bigger than the so-called microcontinent of Madagascar,
09:28and more than twice as large as Greenland, which also happens to be attached to North America.
09:35To understand Zealandia's origins, we must travel back in time,
09:40to the time of the supercontinent Gondwana, comprised of what we know today as Africa,
09:46South America, Antarctica, and Australia.
09:51When Gondwana split apart 80 million years ago,
09:55it was a bit like the stretching of bread dough in a kitchen.
10:00And then you start to pull that big lump of dough apart.
10:03And if you pull slowly, some of those pieces will stretch and get thinner.
10:08Just like Zealandia, which broke off and slowly sank,
10:13because of its relatively thin continental crust.
10:16It's not as thick as the main continents, but it is thicker than the ocean crust.
10:20And geophysicists know that when you have thin crust, it floats lower in the mantle,
10:26and so it sits lower elevation-wise.
10:28And that explains in very simple terms why Zealandia is so submerged.
10:36Now that we've got Zealandia in the scientific arena,
10:39we do hope to consolidate it and to promote Zealandia in New Zealand schools, first of all.
10:44And we hope to get it in atlases, on globes.
10:47We hope that Zealandia will become as common and well-known as any of the other major continents.
10:53Of course, the initial buzz about Zealandia can only help its name recognition.
10:59The notion that something so big and so important could be hidden for so long,
11:05I think captured people's imagination.
11:11Out of sight, out of mind, no more.
11:16Of course, not everything that's undetected is so obviously obscured.
11:27And one remarkable discovery this year offers clues about how some prehistoric creatures could hide in plain sight.
11:37In northern Alberta, Canada, the remnants of a 110-million-year-old dinosaur from the late Mesozoic era
11:44is providing the world with an unprecedented look at a new species, the nodosaur.
11:51A fossil so pristine and complete that it shows the texture, patterns, and color of a prehistoric giant.
12:00The nodosaur is the best specimen we have.
12:03And it's the closest you'll come, until we find a better one, in terms of coming face-to-face with
12:07the dinosaur.
12:09The nodosaur is next to surreal.
12:13A petrified beast caught by Medusa's gaze.
12:18We knew it was good, but we didn't know how good it was.
12:21I think it's the best preserved armored dinosaur in the world.
12:24I'm calling this the Rosetta Stone for armored dinosaurs.
12:31The anatomy of the new species has already given scientists clues to how these animals evolved.
12:37How they radiated and diversified through time.
12:41And it doesn't stop there.
12:45The skin is preserved. It's not just the impression of the skin.
12:48We actually have some of the original biomolecules preserved.
12:52One of the cool things that they tell us for this specimen is that the animal had at least a
12:57component of reddish-brown pigment to its skin.
13:00The coloration aspect is very exciting, so it's cool to know what color it was, but it's actually more exciting
13:07when that has some implications for how the animal lived.
13:11Researchers believe the nodosaur was darker on the back and lighter on its sides and underside.
13:18A method of camouflage called countershading.
13:22Now keep in mind, this was a five and a half meter long, ten and a half animal, covered in
13:28armor, but it still has camouflage.
13:31And to us, that just illustrates how intense the predation was back in the Cretaceous.
13:36You had these very large meat-eating dinosaurs, and they would have also been very visual predators.
13:42So it actually kind of just shows you how extreme that ecosystem likely was back in the Cretaceous.
13:53The plant-eating, slow-moving beast only stood a chance because of its impenetrable coat of armor.
14:00We see three rows of osteoderms.
14:03Those are what are called cervical rings, and it's armor that would have protected the neck of the animal.
14:08And as we move to the side, we see this giant periscapular spine.
14:11It's basically a big armor spine coming off the shoulder, and it's about half a meter long.
14:22And the spectacular specimen still has many secrets to unveil.
14:27The next focus of study are the contents of the nodosaur's stomach.
14:32In addition to having skin preserved all over most of the surface of the animal,
14:36we also have abundant gut contents, so the last meal of the animal preserved inside.
14:44And this is what that stuff looks like.
14:47So we're currently doing all sorts of work on this.
14:51Geochemical work, histological work, and CT scanning, trying to figure out what these spheroid structures are.
14:58And there's been many ideas that part of the diversification of dinosaurs is tied to the diversification of flowering plants.
15:05And it would be great to see exactly which types of plants this guy was eating, and if that hypothesis
15:10makes sense.
15:12We know what dinosaurs ate, how they fought, and now what they looked like.
15:20But there are still many questions to be answered.
15:24And Alberta might just be the place to find them.
15:27It's estimated that there are thousands of fossils hidden underneath the Earth.
15:34But when a six-mile-wide asteroid struck the Yucatan Peninsula 65 million years ago,
15:41dinosaurs had nowhere to hide.
15:54And the resulting global cataclysm of earthquakes, firestorms, and tsunamis ultimately led to their extinction.
16:08Some animals, however, managed to survive.
16:12But how?
16:15Since its discovery in 1978,
16:18investigations of the asteroid's impact crater include data from seismic images
16:23and recently collected core samples from deep within the site at Chicxulhu.
16:31The data paints a devastating picture of destruction
16:35and led scientists to create a broad new survival theory,
16:39focusing on habitat and diet adaptability.
16:43When dinosaurs perished and a vast new ecospace emerged,
16:47the surviving species expanded rapidly to fill it.
16:52This is called adaptive radiation.
16:56A recent study shows that one out of ten frog species descend from the original three frog species
17:02that survived the Cretaceous tertiary extinction event.
17:09Frogs were able to escape extinction for a number of reasons.
17:13They live in an aquatic habitat that offered protection.
17:17Their small size and unique metabolism allow for better endurance of environmental stress.
17:25Eventually, when vegetation returned, they were able to diversify worldwide
17:30and adapt to new lives in trees.
17:35Birds, too, exhibited the same adaptive radiation around the same time.
17:41A newly found 62-million-year-old mouse bird fossil in New Mexico
17:46helped paleontologists map the diversification of land birds,
17:52which can be traced back to nine original ancestors, which survived the event.
17:59Warm-blooded, birds' feathers insulated them from temperature extremes.
18:05Their small size and ability to fly allowed for easier escape from hostile and barren terrain.
18:12And their diet of seeds, worms, and insects gave them the edge after much of the Earth's surface plant life
18:19had died.
18:22In the end, the ability to adapt to changing conditions proved a key characteristic for the survival of many ancient
18:30animals,
18:31including our smallest mammal ancestors.
18:37just as it may be for humans today, as we confront the challenges of climate change.
18:49The city of Miami Beach already knows what it means to wade through sea level rise.
18:57In recent years, residents have experienced elevated high tides at certain times of the year.
19:04Known as king tides, these events are clear evidence of incremental increases.
19:10Right now, we are definitely witnessing sea level rise impacts.
19:15These high tide flooding events that are growing in severity.
19:18More often, deeper, more widespread.
19:21That's sort of a pattern that we expect will continue.
19:25That means huge financial costs by the year 2100.
19:32Another predicts 2.5 million Miamians could become sea level refugees and leave the area.
19:42It's not only Miami.
19:44All around the world, sea levels are expected to rise.
19:49The question is, by how much?
19:56In adopting a multi-pronged approach, Miami Beach has committed 400 to 500 million dollars to combat sea level rise.
20:06Building water pumps and raising their defenses.
20:10With the continual issue of climate change and sea level rise, we're seeing an increase of water level every year.
20:17We had to make changes to adapt to this future condition.
20:20What you're seeing here, we put a boardwalk initially to give some height, but we found that that wasn't protecting
20:26the city.
20:27What we've done here is we've increased the levels of our new seawall.
20:31The new wall you see in the background here is our new standards.
20:34This was good for approximately another 50 years, and we're going to see water levels challenging even that new seawall.
20:41Raising its elevation, Miami Beach seeks to stay dry and take control of its future.
20:48The city's philosophy or our culture is rising above.
20:51We believe that we can meet the challenge.
20:53And the challenge is not only in rising above, meaning elevation.
20:57It's rising to and withstanding the challenges that have come with sea level rise due to climate change.
21:03As a city engineer, I have complete faith that we can win, we can mitigate, we can survive.
21:13Of course, the Earth's oceans have risen and fallen many times during the planet's history.
21:20And new archaeological evidence suggests these shifting shorelines may conceal clues about the earliest Americans.
21:30Until just recently, archaeologists generally agreed that the earliest people to populate North America were the Clovis people,
21:39dating back to some 12,000 to 13,000 years ago.
21:44But a group of scientists in San Diego, California, have a different theory.
21:50We have the bones, the fossils, the distribution, the rocks, the date.
21:55We have evidence for humans in North America 130,000 years ago.
21:59We realize that that is a startling claim.
22:03But the scientific community is struggling with the idea that humans arrived in North America 130,000 years ago.
22:14The study of early humans in the New World has been very political and very controversial for over 125 years.
22:20It's an old mystery yet to be solved, deciding who got to North America first and when.
22:27Welcome, and thank you for joining us this morning at the San Diego Natural History Museum
22:32as we share some exciting news about a discovery made right here in San Diego.
22:36Well, back in 1992, Caltrans was doing improvements to State Route 54, which involved adding a couple of new travel
22:47lanes.
22:48And Richard Cerruti, who's a field paleontologist here at the museum, was monitoring excavations on the very north side of
22:55the freeway alignment
22:56and saw this little puff of, let's say, tusk material being scraped up by an excavator and said,
23:06stop, let me go look at this.
23:09The bones that Richard Cerruti found belong to an ancient mastodon.
23:15That's one tooth, so it's characteristic of American acid.
23:22Were these giants sharing North America with early man 130,000 years ago?
23:29The answer may lie in the position of the bones and tools found at the site.
23:34There are anomalous fragments of rock, anomalous fragments of tooth enamel scattered throughout the site that just don't make sense.
23:45Could these stones amongst ancient bone remnants have been an early form of primitive tools?
23:51We felt that it was important to produce a map where we carefully plotted or precisely plotted the position of
23:59all the bones and the stones
24:02or whatever else is in there so that we can understand what the general pattern is.
24:07It's thought that the tools found with the mastodon bones were used for butchering the animal.
24:14So this is one of the cobbles that we hypothesized was used as a hammer stone.
24:19130,000 years ago where there was a carcass of a mastodon,
24:26these people were trying to recover raw materials from it.
24:29They had a problem, how do we break these bones?
24:33They look over into the active river channel, find some cobbles of the appropriate size and weight,
24:39bring them back to the site.
24:42And if you look closely there are some striations coming off of that
24:45that are indications of where this flake has come off.
24:49The cuts in this rock led the San Diego team to conclude that these were actually tools used by humans.
24:57An idea that Demir says might not be so far-fetched.
25:02Dr. Stephen Holin is co-director of the Center for American Paleolithic Research in South Dakota.
25:10He was part of the team that evaluated the findings from the San Diego excavation site.
25:16So what do we got in here, Steve?
25:18Looks like vertebrae.
25:19Yeah, it does.
25:20I said, I can't get my mind around this.
25:23This site has to be really, really old, but yet here's evidence of humans.
25:28I said it goes against everything I thought I knew and everything I have ever been taught.
25:34Holin evaluated the mastodon bones and the stone tools recovered from the excavation site.
25:40We would take the drawers out of the cabinets in here and bring them in on this table
25:44and look through them, paleontologists and archaeologists together.
25:48Richard Cerruti came in, so there were four of us, my wife Kathleen, Tom, and I.
25:51And we would look through and we would look for these very diagnostic pieces.
25:55And one of the things that we got all excited about first were these cone flakes
25:59that form in a circle around the point of impact from the hammerstone.
26:02And based on the experiment that we'd done in Africa, breaking an elephant femur with a big hammer,
26:09we saw the same kinds of fracture patterns that we did experimentally.
26:16Holin specializes in evaluating broken bones at archaeological sites,
26:21looking for human causes,
26:24as this video shows from a test he conducted in Africa two years prior to working on the San Diego
26:29project.
26:34As we puzzled over this, we kept coming back to this one explanation that explains all the data,
26:41was that humans did this.
26:45The detective work by the San Diego Natural History Museum team
26:50was capped by the age dating that Richard Cerruti had done
26:53to prove the age of the mastodon bones he discovered.
26:59This is one of the specimens that he used in his analysis.
27:02He cored it and he also sliced it.
27:05And after analyzing over a hundred microsamples from this specimen
27:10and two other specimens of bone from the site, yielded an age of 130,000, plus or minus 9,000.
27:18So after the article came out, there has been no critic come out to say that the dating is incorrect.
27:23In fact, other specialists in uranium series dating have come out and said the dates look perfectly good.
27:29So we're very comfortable with the dates.
27:33While humans' arrival in the Americas may have occurred earlier than previously thought,
27:38new dating of another paleontological find found in a South African cave
27:44could soon upend long-held theories about the evolutionary tree of primates and early humans.
27:54When we actually got into the chamber and could start removing it,
27:57we realized that not only was there one individual lying there on the surface,
28:02but the floor was literally comprised of Homo taledi.
28:05There are thousands and thousands and thousands of remains down in those chambers.
28:10And all you have to do is sweep the surface off and there they are.
28:14So the first time I sort of slid through that hallway into the open area where the chamber is
28:19and sort of started looking around, you know, you're only wearing a headlamp, so you just see flashes.
28:25But every flash of my headlamp showed bone.
28:28So I think right at that point I realized that we had a lot more than the original photographs actually
28:35had portrayed.
28:36So that was pretty exciting.
28:38Homo taledi isn't really similar to any known hominid species in its entirety of its package.
28:45You've got little bits and pieces of almost everything we've ever found.
28:49Parts of the skull, if you just look at it quickly, look a little bit like Homo erectus.
28:53Got a very small brain. Other parts of the skull look very modern, like Homo sapiens.
28:57It gets stranger and stranger as you move down the body.
29:00You get the ape-like shoulders.
29:01You get these more and more human-like arms which end with a hand that's human proportion.
29:06I was actually at the London Natural History Museum and Homo naledi was on the wall
29:13and then there was an estimated age between 1.2 and 1.8 million years.
29:17But then when we actually did the scientific dating of those teeth,
29:21this is when things got very interesting because then we got an age of 200,000 to 300,000 years
29:27old.
29:28When we got a date that was much younger than that, a quarter of a million years give or take,
29:34we realized that we were dealing with a primitive creature almost like a time traveler
29:38that had come down from deep times to a point where it is very possible
29:42that Homo naledi was in direct contact with the emergence of modern humans.
29:48We never thought that was possible in Africa until this moment.
29:51We thought that there was effectively during that entire time period of the middle Pleistocene,
29:57late middle Pleistocene, one form, a big brain form of Homo sapiens.
30:02Now there are two and that adds incredible complexity to our record.
30:06The world of Homo naledi and other early humans was different than it is today.
30:12A veritable Garden of Eden, teeming with life, pure and free from pollution.
30:24Few places like this still exist, and most of them quite remote.
30:31But look just a few feet underwater and you can find one of the most productive and overlooked ecosystems on
30:38Earth.
30:39Scientists recently learned that seagrass meadows help scrub the surrounding water clean of bacteria from raw sewage and other pathogens.
30:49A recent study of polluted waters in Indonesia showed levels of harmful bacteria to be 50% less in spots
30:57with robust seagrass beds.
31:00Leading to healthier fish and coral in the surrounding area.
31:07You see, seagrasses oxygenate the water, trap sediment that might otherwise float freely, and host tiny microbes that kill many
31:18harmful bacteria.
31:23Eliminating toxins improves the health of any system, and the workings of a human body is no different.
31:33In athletics, though, they say no pain, no gain.
31:37A nod to the physical effort required to increase endurance.
31:42And enjoy the health benefits of exercise.
31:46But new pharmaceutical research also aims to make those benefits more easily accessible.
31:53The potential benefit of a drug that can tune you up in the way in which you normally get tuned
32:00up by exercise could have really dramatic effects.
32:06Playfully known as the exercise pill, the experimental drug shifts metabolism by triggering genetic instructions for the body to burn
32:14fat, instead of sugar, during exercise.
32:18Something that doesn't normally happen until after extensive training and conditioning.
32:24Recent tests increased the endurance of otherwise sedentary mice, which also proved to be resistant to weight gain while on
32:32the drug.
32:32We have two groups of mice and one group on the drug, the other group as a control without the
32:41treatment of the drug.
32:42So we were quite surprised to see the astonishing results.
32:48The mice treated with the drug, they can run almost 100 minutes longer than the one that are not treated.
32:56The increase was around 70 percent.
32:59Researchers ultimately hope their product can improve the health of the disabled, elderly and obese.
33:07There are many reasons why people can't either walk or run or exercise.
33:14And the idea is if you can bring a small molecule into the picture that can confer the benefits of
33:20fitness without training, you could really help a lot of people.
33:25From energizing our bodies to powering societies.
33:30So we are just waiting for the next experiment. It's going to happen in 10 seconds.
33:38There you go.
33:40You see the flickering of the plasma? We are creating fusion here.
33:43This is our little sun. It's extremely hot.
33:46Each day, every 20 minutes, researchers build the sun.
33:51At the Cullum Fusion Center in Oxfordshire, Britain.
33:55Generating temperatures greater than 200 million degrees, these nuclear fusion trials would be impossible without JET.
34:04The joint European Taurus, a donut-shaped plasma containment vessel.
34:10At this point, we're the most important experiment in the world.
34:14Thanks to JET, where energy is created by combining hydrogen atoms.
34:19There's heavy hydrogen, which we call deuterium, and there's super-heavy hydrogen, which we call tritium.
34:26And when they're running around at these temperatures like 200 million degrees, they bang into each other with immense speed.
34:34And when they do, and they get close enough, what we call the strong force, which binds the nucleus of
34:41atoms together, grips them, pulls them together, and they fuse, and they make helium, and they spit out a neutron.
34:49Fusion really is the perfect way to make energy.
34:52And yet, despite fusion's transformative potential to provide safe and sustainable energy to the world, the program faces an uncertain
35:01future.
35:02While the British government committed to pay for its share of the experiments up to the year 2020,
35:09Brexit, its planned departure from the European Union, may also lead to the UK's withdrawal from scientific agencies like Euratom,
35:17the European Atomic Energy Community.
35:21Some say this could jeopardize jet logistics and operations,
35:26and perhaps also the larger, next-generation fusion experiment,
35:31currently being built in southern France.
35:39If fusion represents harnessing the physical power of the sun,
35:44a moment of darkness reflected its emotional power.
35:51an awe-induced euphoria experienced by millions,
35:56as the first total solar eclipse over North America in three decades made its way across the United States.
36:13It's the most unnatural, natural phenomenon I ever saw.
36:22This is a solar eclipse, and just what people witnessed on August 21st along a 70-mile-wide path.
36:33First along the Oregon coast at 10.15 a.m. Pacific Daylight Time,
36:37and last in South Carolina, 94 minutes later.
36:51The uncommon coupling was the most viewed and photographed eclipse ever recorded.
37:05And yet, even as the sun reemerged from the moon's shadow,
37:09some earthly domains remained, as always, far removed from its rays.
37:18Like the cave chambers, 300 meters below Mexico's Nika mine.
37:24Enormous, razor-sharp crystals dwarf human explorers.
37:31While today the cave is totally submerged,
37:34previous expeditions collected bizarre life forms from these crystal giants.
37:40They call this place Hell on Earth.
37:43Temperatures climbed to 135 degrees Fahrenheit,
37:47with over 80% humidity.
37:50Even with life-saving body suits, no visit can safely last longer than a half hour.
37:56Yet deep within this extreme environment are life forms which exist nowhere else,
38:02known as extremophiles.
38:05NASA astrobiologist Penny Boston and her team found 40 strains of mineral-eating organisms.
38:12Trapped within the crystals here, they collected sample microbes.
38:17Some dormant, but alive.
38:20Estimated to be between 10,000 and 50,000 years old.
38:24Including genetically unique and previously undiscovered life forms.
38:29Any extremophile system that we're studying
38:32actually allows us to push the envelope of life further.
38:36And we add it to this atlas of possibilities
38:39that we can apply to different planetary settings.
38:44By expanding the definitions of life on Earth,
38:47and where to find it.
38:49Boston's findings could impact the search for life beyond our planet.
38:55On places like the protoplanet Ceres,
38:58the largest object located within the solar system's asteroid belt.
39:03And one of the scientific targets of NASA's Dawn space probe.
39:09And in February of 2017, startling and unexpected news began coming in.
39:17My colleague found a spectral signature in her data that is consistent with,
39:24or the same signature, of aliphatic hydrocarbons.
39:29So here we're finding maybe the building blocks of biological material.
39:34Seen here in red, the organic materials are thought to have originated in the dwarf planet itself.
39:44Dawn's study of Ceres also revealed evidence of water and volcanic activity,
39:50further raising the scientific profile of Ceres,
39:53no longer considered a barren rock.
39:58However, Dawn isn't the only NASA spacecraft uncovering new surprises about our solar system.
40:14The Juneau Explorer became fully operational in February of 2017.
40:21Astonishing researchers with the steady stream of images and scientific data it's sending back to Earth.
40:33Jupiter is by far the largest planet in our solar system,
40:37leaving Juno with a whole lot of ground to cover.
40:40And although it is the second brightest planet in our night sky,
40:44its formation and composition have left us in the dark.
40:49Previous NASA missions have given us some understandings of its moons,
40:52small dust rings, and atmosphere.
40:56But we've not been able to see past the Van Gogh-like swirls of dense red, brown, yellow, and white
41:03clouds
41:04that paint the planet.
41:07At least, not until now.
41:10Each individual image is awe-inspiring,
41:13especially those captured when Juno came within 5,000 miles of Jupiter's great red spot,
41:19the planet's most famous storm.
41:26Pouring over data from Juno's microwave radiometer,
41:30scientists hope to learn more about what powers the tempest
41:34and how it differs from other Jovian storms.
41:37This critical instrument measures six distinct ranges of thermal radiation
41:42as it peers more than 300 miles beneath Jupiter's clouds.
41:48To create a three-dimensional model of Jupiter's atmospheric environment.
41:55The first time we're looking inside of Jupiter into the interior,
42:00and what we're seeing is that it doesn't work at all like we had predicted.
42:04Almost every model that has the interior motion,
42:07how the magnetic field, the gravity field, how the deep atmosphere works,
42:12it's all different.
42:16Current modeling estimates that the cloud cover is roughly 30 miles thick.
42:22Below it, there lies a 13,000-mile layer of swirling hydrogen and helium
42:27that changes states from gas to liquid as it nears the center,
42:32leading to a 24,000-mile-deep sea of metallic hydrogen.
42:36If we can probe it and work out the abundance of elements in it,
42:41hydrogen, helium, the higher elements as well,
42:44and work out roughly what that mix is,
42:47it'll tell us something about not only how Jupiter was formed,
42:50but how the solar system might form.
42:53If there is a bunch of rocky material in the center of Jupiter,
42:56it means that in the early solar system before Jupiter formed,
43:00that rocky substances were probably coming together
43:03and Jupiter got built around those.
43:05It could be that Jupiter was built without any of those
43:09and that it just collapsed sort of like the sun,
43:11and there is no rocky material or core of heavy elements in the center.
43:18Strangely though, gravity data collected so far points to a new possibility,
43:23a somewhat larger than previously thought and perhaps partially dissolved core,
43:30leaving Jupiter experts with more questions than answers.
43:34We're putting the pieces of the puzzle together and it's exciting,
43:39but we don't have the whole picture yet.
43:43Juno's primary mission is scheduled to continue until February 2018.
43:49But this past year,
43:51NASA saw another of its extraordinary explorers come to the end.
43:56And we are in the atmosphere.
43:59As the Cassini space probe plummeted into Saturn's atmosphere,
44:03in a fiery death spiral.
44:06Roughly one minute to loss of signal.
44:08The culmination of the craft's revolutionary scientific quest.
44:13Call loss of signal at 115546.
44:18The signal from the spacecraft is gone.
44:23Congratulations to you all.
44:25This has been an incredible spacecraft and you're all an incredible team.
44:35She's rewritten the textbooks about Saturn, the rings, the moons, Titan.
44:41So many things have changed because of Cassini.
44:45From its launch 20 years ago to its bold grand finale,
44:50the Cassini Huygens mission has unveiled some amazing discoveries.
44:54Saturn is ablaze with storms of unimaginable force.
44:59The place crackled with giant lightning strikes.
45:06The rings are even more dazzling than imagined.
45:11Stretching across hundreds of thousands of miles.
45:15They're made of particles of pure water ice.
45:18Some microscopic.
45:21Some the size of mountains.
45:25They break apart and they reform.
45:28So there's this beautiful cosmic dance going on inside the rings.
45:43Cassini also carried a little lander called Huygens.
45:50Which became the first probe to land on a moon other than our own.
45:56Its target, Titan, because of its atmosphere.
46:01And as those first pictures came back, we just saw more and more haze and fog and haze and haze.
46:07Until finally the probe broke through that haze and we got to see the surface of Titan for the first
46:14time.
46:14Huygens landed on the surface of what looked like a mud flat.
46:19The surface temperature was minus 350 degrees Fahrenheit.
46:24And these pebbles were made of methane ice.
46:29The nearby lake, a lake of methane.
46:34Then Cassini went into orbit around Titan and revealed with its radar system that there indeed are lakes of liquid
46:40natural gas and other molecules on the surface of Titan.
46:44They evaporate just like here on Earth, create clouds of methane which rain back on the surface creating rivers of
46:51liquid natural gas and lakes.
46:53Could there perhaps be some very interesting life in the lakes on Titan?
46:58But there were dry formations here too, including dunes that stretched for miles and miles.
47:05Reaching 100 meters high.
47:08And 3000 meter mountains.
47:10Suggesting tectonic forces at work here, similar to those on Earth.
47:18Next, Cassini headed for a close look at Saturn's tiny moon called Enceladus.
47:25Here, on the moon's south pole, strange blue cracks, dubbed tiger stripes, 75 miles long and hundreds of feet deep,
47:36resemble fault lines here on Earth.
47:43Cassini's thermal sensors picked up heat coming out of the ice ball.
47:48200 degrees warmer than the rest of the planet.
47:54Cassini then captured giant jets of water spewing hundreds of miles into space from the tiger stripes.
48:01Shooting out at 1200 miles per hour.
48:05Vaporizing and then freezing.
48:10Back on Earth, Cassini's stunned controllers quickly reprogrammed the probe to fly right through the jets, collecting particles.
48:22And what they found was even more stunning.
48:26Organic molecules.
48:27The basic building blocks of life.
48:31Enceladus is really special.
48:33It's giving us free samples.
48:36Because the geysers erupting, they could guide the spacecraft very close and look to see if there's water there, and
48:42there is water.
48:42Here on Earth, wherever there's liquid water, whether it's deep in the ocean and very hot or in rocky places
48:48or in ice, there's microbial life.
48:50So it certainly suggests microbial life could have evolved on Enceladus because it has all the properties that the Earth
48:57had when life began here.
49:01NASA controllers plotted the probe's deadly descent into Saturn's atmosphere.
49:18Productive until the end.
49:21Cassini relayed detailed information about the planet's environment.
49:25And then she burned like a meteor and vaporized.
49:32Scientists will build on Cassini's contributions.
49:35As the search for extraterrestrial life continues within our solar system.
49:41And beyond.
49:42Perhaps around the star system 39 light years away.
49:47Known as TRAPPIST-1.
49:50The first place found, NASA announced, to have multiple planets.
49:56Three here, circling a single star inside the habitable zone, where liquid water can exist.
50:04Well, with this discovery, we've made a giant accelerated leap forward in the search for habitable worlds and life on
50:10other worlds, potentially speaking.
50:12The TRAPPIST-1 system has really captured our imagination, because with this amazing system, we know that there must be
50:19many more potentially life-bearing worlds out there just waiting to be found.
50:23Earth-like in size and temperature, these three far away worlds suggest endless possibilities.
50:38The discovery gives us a hint that finding a second Earth is not just a matter of if, but when.
50:46These questions about, are we alone, are being answered as we speak in this decade and the next decades.
50:54So I'm really excited about this.
50:57It's been an astonishing year for sure.
51:01And as our universe reveals more of its secrets, far out in space and closer to home,
51:08our foundation of knowledge will continue to grow, promising ever more to come.
51:43The
51:58Transcription by CastingWords
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