• 5 months ago

Category

📺
TV
Transcript
00:00We live in a violent universe.
00:07Planetary winds rage at six times the speed of sound.
00:12Lightning storms stretch for thousands of miles.
00:16Dust storms engulf entire worlds.
00:19We can have planetary storms the like of which we never see here on the planet Earth.
00:26The largest storms can be on the scale of entire galaxies.
00:31Sometimes those massive stars can literally explode.
00:36The universe is a chaotic place.
00:41Earth has storms.
00:43Other worlds have megastorms.
00:46Storms almost too vast to imagine.
00:50Yet from the violence emerges a ray of hope.
00:55We kind of owe our existence to these sorts of events, these sort of galactic storms.
01:00Could megastorms be necessary for life itself?
01:05On some planets, storms are impossible.
01:27Superheated Mercury is too small and too close to our sun to have a significant atmosphere.
01:34And no atmosphere means no storms.
01:41But move out, away from the sun, and we find worlds with turbulent, chaotic atmospheres.
01:53We can spawn some of the most awe-inspiring megastorms in our solar system.
02:04This is Venus, a planet completely shrouded with clouds.
02:13Winds rip around the upper atmosphere at over 300 miles per hour.
02:21At 35 miles above the surface, the winds are whipping around in a ferocious pattern
02:28that basically carries the cloud features around the entire planet every four days.
02:36Venus is closer to the sun than Earth, and it's heat from the sun that drives the wind.
02:46The circulation pattern of Venus's clouds is actually quite simple.
02:49There's a warm side of Venus and a cold side.
02:51And as air warms up and rises on the day side of Venus, it spreads around to the night side.
02:56So there's this continuous current.
02:58It's actually quite a lot simpler than the atmospheric circulation on Earth.
03:03Venus's winds circulate faster than the fastest hurricane on Earth.
03:10But they look very similar.
03:16A Venus Express probe captured these remarkable images of the planet's south pole.
03:26One of the great mysteries of Venus, which actually had jaws dropping in the halls of many astronomy departments,
03:32is the fact that we have hurricanes at the poles of Venus, especially in the southern hemisphere,
03:37that have two eyes, not one eye, but two eyes.
03:42We've never seen this before on such a planetary scale.
03:49Venus's double-eyed vortex is 1,800 miles wide.
03:54Two hurricanes whirl around each other.
04:01If you could descend into the vortex of Venus,
04:04something I would love to do, at least with a remote machine,
04:11I think you would see some kind of a fantastic wall of cloud
04:16in this sort of twisting form spinning around you at ferocious speeds.
04:20It would be quite a sight.
04:31It's a mystery how deep this raging, spinning vortex goes.
04:36But maybe this megastorm eye descends to the planet's surface.
04:42Down here, permanent twilight bathes a volcanic landscape.
04:47And the atmosphere's colossal weight creates immense pressure.
04:53The atmospheric pressure on Venus is about 100 times that of the Earth.
04:58Think of taking a car, squeezing it down to about a square inch
05:02and putting it on every square inch of your skin.
05:06You would be flattened within a fraction of a second
05:09because of all that pressure.
05:12Venus's dense atmosphere creates one of the strangest megastorms imaginable.
05:18Four miles per hour winds with the force of a hurricane.
05:25The winds on the surface of Venus are actually very slow
05:28because Venus has a very slow rotation rate.
05:31It takes Venus about eight months to turn once around with respect to the sun.
05:37The crushing atmospheric pressure rams gas molecules together so tightly
05:43that they feel more like a liquid.
05:47A gentle four mile an hour breeze packs a brutal punch.
05:53It's like a hurricane in slow motion.
05:57Winds on Venus are totally unlike anything we see on the planet Earth.
06:02You would almost feel like a molasses effect.
06:04It'd be quite difficult to simply walk and run right through the wind.
06:17Venus's surface is so hostile that life is impossible here.
06:28But the upper atmosphere's faster winds hold an extraordinary possibility.
06:36I harbor this, I don't know if I would call it a hypothesis or a scientific fantasy,
06:41but I do think it's plausible that there could be some kind of life living in the clouds of Venus.
06:47There are certainly energy sources.
06:49There's sunlight and there are certainly nutrients.
06:52There's carbon, there's hydrogen, there's oxygen.
06:54All the stuff we think of that you need to make life exists in the clouds of Venus.
07:00Earth's upper atmosphere is full of life.
07:04Microscopic bacteria drifting on the wind.
07:10Could Venus be the same?
07:14Perhaps one day we'll send a probe to find out.
07:21Leave Venus behind and the next planet is Earth.
07:32Here too the weather gets extreme.
07:36We are bombarded by tornadoes, hurricanes, and these, dust storms.
07:47On Earth, they're localized.
07:52But on the next planet out, they engulf an entire world.
08:01NASA Jet Propulsion Laboratory, California Institute of Technology
08:10Over 100 years ago, astronomers thought they had found life on Mars.
08:18A dark wave spread from the pole towards the equator.
08:23They thought it was springtime vegetation spreading across the planet.
08:31They were right about the season.
08:36Mars tilts at roughly 23 degrees like the Earth, so you would have summer, fall, winter, spring like the seasons.
08:44Seasons bring weather.
08:48The shadow astronomers saw was actually dark rock uncovered by a violent dust storm.
08:58It's all because of the way the planet tilts.
09:06The Earth takes one year to orbit the Sun.
09:12Somewhere in the northern hemisphere leans away from the Sun and we get our winter.
09:20In June it leans inwards, our summer.
09:30Mars has gigantic planetary dust storms the like of which we've never seen here on the planet Earth.
09:38Mars has around the same tilt as Earth, and springtime means storms.
09:46The Martian surface vanishes under a cloud of raging dust particles.
09:54On Earth we get dust storms too.
09:58They can be devastating, swallowing entire cities.
10:09July 5th, 2011. Arizona.
10:15An unstoppable 5,000 foot high wall of dust smashes into Phoenix.
10:22Day turns to night.
10:26Thousands of tons of dust settle over the city.
10:32But the disaster stays in one place.
10:44Mars' dust storms can engulf the entire planet.
10:50On Mars, when dust gets kicked up once, it lands, it can get kicked up again and again.
10:56The dust is reusable.
11:00On the Earth, when dust gets kicked up and then finally settles out, it's probably going to settle out into the ocean where it's gone for good.
11:08There's nowhere on Mars where there isn't ready dust and sand to add to that storm.
11:14So these storm systems can kick up and last weeks or even months.
11:20Mars' incredibly dry atmosphere contributes to the storm's size and power.
11:28In the case of the Earth, dust that gets up into the atmosphere is rapidly washed out by the rain and gets into the ocean.
11:36In the case of Mars, there's no comparable rain to wash the dust out.
11:40So once the dust gets into the atmosphere, it just sits there until the particles by themselves are able to slowly settle out.
11:48A lack of rain allows Mars' dust storms to cover the planet.
11:54But dust storms on Mars can be equally spectacular on a much smaller scale.
12:02NASA rovers captured these extraordinary images.
12:07Dust devils sucking up fine dry iron oxide dust.
12:15The biggest dust devils can reach six miles into the sky.
12:20They pump fine particles high into Mars' atmosphere, creating a haze of dust that may help control the planet's dry climate.
12:32And lead to a planet-wide megastorm.
12:37Even on Mars, dust storms this big are rare.
12:41Astronomers have detected just 10 in the last 100 years.
12:48What the ancient astronomers mistook for life was a megastorm.
13:01But even a planet-covering dust storm is dwarfed by the weather on the next planet out from our sun.
13:12This is the giant of our solar system, Jupiter.
13:31Jupiter is gigantic.
13:34It's two and a half times more massive than all the other planets in the solar system added together.
13:42It's also home to gigantic megastorms.
13:47Jupiter's high-speed rotation drives vast bands of counter-rotating clouds.
13:55Colossal storms build along the boundaries.
14:00And this is the biggest of them all.
14:05The oldest storm in the solar system.
14:1115,000 miles across and over 300 years old.
14:17The Great Red Spot.
14:23Around the edges, turbulent winds rage at over 300 miles per hour.
14:34The Great Red Spot is a giant vortex, meaning that in the case of the Red Spot, it has a high-pressure center with winds that swirl around the outer edge.
14:42So, in that sense, the Great Red Spot is a little bit like a hurricane.
14:49A hurricane with a difference.
14:52On Earth, hurricanes feed off heat from the ocean.
14:58When they hit land, they start to die.
15:03So, on average, they last only about a week.
15:10Jupiter does not have land.
15:12Jupiter is a completely gaseous planet, and the friction there is very weak.
15:16And so a vortex, like the Great Red Spot, can last indefinitely.
15:19There's nothing to slow it down.
15:22To keep going, all the Red Spot needs is a power source.
15:32On Earth, ultimately, that's heat from the sun.
15:37But Jupiter's five times farther from the sun than us.
15:45Heat from the sun is not enough to drive the Red Spot.
15:51Instead, Jupiter has an internal power source, its own immense gravity.
16:06In 1995, NASA launched a probe straight toward the giant planet's heart.
16:15It plunged into Jupiter's upper atmosphere at over 106,000 miles per hour.
16:24As it fell, the planet's crushing gravity ratcheted up the pressure,
16:3010, 15, 20 times what we feel on Earth.
16:36Winds gusted to over 400 miles per hour.
16:45The probe gave out just 100 miles in, crushed by pressure,
16:52and fried by the incredible heat the pressure generated.
17:00If the probe made it deeper, it would have reached a vast silvery ocean.
17:09Intense pressures here turn hydrogen gas into a churning metallic liquid,
17:16superheated to over 40,000 degrees Fahrenheit.
17:24Jupiter's interior pumps out about twice as much energy as the surface gets from the sun.
17:37This is Jupiter's power source, the heat that drives its massive megastorms.
17:47All of the convection, all of the heat, comes from the hot, dense interior of the planet itself.
17:52So the bands of clouds that you see that are even counter-rotating, going in different directions,
17:57those are all driven by the internal heat of Jupiter itself.
18:05Jupiter's internal heat drives its violent megastorms.
18:10But the giant planet may hold clues to an even deeper mystery.
18:17Could life exist on other worlds?
18:26NASA's Cassini probe studied Jupiter as it flew past en route to Saturn.
18:33It made an extraordinary discovery.
18:37Strange white clouds just north of the great red spot.
18:45Clouds just like the clouds on Earth.
18:49Droplets of liquid water.
18:52Could Jupiter have the ingredients for life?
18:56The question of life on the giant planets is an interesting one.
18:59You have many of the ingredients for life.
19:01You have sunlight coming in.
19:03There's liquid water, at least in the form of cloud droplets.
19:06On the other hand, if life can easily exist in clouds,
19:09you might expect that bacteria and algae would populate the clouds on Earth and the clouds would be green.
19:13We don't see that on the Earth.
19:15We do see microbes at many altitudes throughout the Earth's atmosphere,
19:18but they seem to largely be blown off of the surface.
19:23It's likely that life on Earth began on a solid surface.
19:29But could life evolve without one?
19:34There's no surface on Jupiter,
19:36and so that makes it difficult for organisms to have a constant source of water.
19:42So if you imagine yourself being a little bacterium inside a cloud droplet,
19:45you're going to be in deep trouble when that cloud droplet evaporates.
19:52Whether life exists in Jupiter's clouds or not,
19:56gas giants like Jupiter and its neighbor Saturn have all the right ingredients.
20:03Water, heat, and one other vital element, a spark.
20:12Lightning on an unimaginable scale.
20:34These haunting images are from NASA's Cassini probe.
20:40Its mission, to explore one of the solar system's most awe-inspiring planets, Saturn.
20:51The probe reveals Saturn's rings, moons, and the planet itself in near-perfect detail.
21:04Chaotic bands of cloud race around Saturn at more than a thousand miles per hour.
21:19Finding storms here was no surprise.
21:24It's a planet of storms.
21:31But this was astonishing.
21:35A bolt of lightning.
21:38A gigantic thunderstorm on an alien world.
21:48Lightning creates some of the most spectacular weather on Earth.
21:56Electrical tension builds between the top and bottom of a vast 55,000 feet high storm cloud.
22:05A maelstrom of water vapor, rain, and ice.
22:14Tiny ice crystals drive up past hailstones falling down.
22:20As they rub past each other, it builds up a charge.
22:25When the strain gets too great, you get an electric spark.
22:39On Earth, the average lightning storm stretches 15 miles.
22:45On Saturn, they can reach around the whole planet.
22:51There are examples of lightning storms on Jupiter and Saturn where the anvil cloud,
22:56in other words, the big cloud at the top of the storm, starts small and grows to be 20,000 kilometers long.
23:02That's the size of the Earth.
23:04On Saturn, we registered one lightning storm that was 10,000 times greater than any lightning storm found on the planet Earth.
23:14Lightning is hotter than the surface of the sun.
23:21The atmosphere literally explodes.
23:25The sound we call thunder.
23:33On Earth, it's the sound of new life.
23:43Lightning seems scary and destructive, but actually it's very productive for life on Earth.
23:48And the reason why is because of its influence on atmospheric chemistry.
23:54Every bolt literally burns the air.
24:00When you have a lightning discharge, you get this very high temperature, very energetic plasma,
24:04and that breaks up the nitrogen molecules in the atmosphere, frees up those nitrogen atoms to enter into other kinds of molecules.
24:12And those nitrates formed by lightning allow nitrogen to go into the soil as basically fertilizer,
24:20enter into plants, enter into the life cycle.
24:23So it's the lightning that frees up nitrogen atoms in the surface of life on Earth.
24:29Earth experiences 8 million lightning bolts every day,
24:36helping life evolve and colonize the planet.
24:49But for Saturn, lightning alone may not be enough.
24:54There's nowhere for alien life to live.
25:00One place in our solar system may solve that problem.
25:05Saturn's moon, Titan.
25:08It has an atmosphere.
25:10It has lakes of liquid methane.
25:16And its own bizarre brand of megastorm.
25:25Saturn is almost 900 million miles from the sun.
25:31This far out, orbiting the sun takes time.
25:37Saturn's year is nearly 30 Earth years long.
25:44Right now it's spring, and things are heating up.
25:53Now we're moving into the summer cycle of Saturn.
25:56So the atmosphere is slightly heating up, even as distant as Saturn is from the sun.
26:00We've got a little more energy, and we're seeing the most speckles.
26:04After years of frozen silence, Saturn is coming alive.
26:10Scientists have waited nearly 15 years for the sun to light up its north pole.
26:16To reveal extraordinary details,
26:20we're going to have to take a closer look.
26:25Scientists have waited nearly 15 years for the sun to light up its north pole.
26:31To reveal extraordinary details about one of the strangest megastorms in the solar system.
26:42Saturn's unique hexagon storm.
26:49A hexagonal pattern, how can that be?
26:53In Mother Nature, we have jagged objects.
26:55We don't have geometric figures arranged precisely,
26:58especially at a gigantic planetary scale.
27:01However, there's some theories.
27:03If I take a bucket of water, or a bathtub, and simply vibrate it,
27:07I get waves, waves that travel.
27:10But there's another kind of wave.
27:12You have traveling waves, but then you have stationary waves.
27:15Inside a bucket of water, you can get resonances.
27:18Water pulsates like this.
27:20And you can also get them to pulsate in a circle like this,
27:24to create regular patterns.
27:26These are called stationary waves.
27:28And we think that this mysterious hexagonal pattern on Saturn
27:31is a hexagonal standing wave.
27:39The megastorm at Saturn's north pole is a wind that travels at hurricane speed,
27:45cornering sharply six times as it races around the planet.
27:53The central clearing is so big, you could fit four Earths inside.
27:59What lies beneath its surface is a mystery.
28:07As Saturn warms from spring to summer, another world comes alive too.
28:15One of Saturn's moons, Titan, is warming up.
28:21And with the warmth come the storms.
28:26One of the most interesting moons in our solar system is Titan.
28:30It's straight out of science fiction.
28:32It's an object with yellow skies and methane clouds that is truly remarkable.
28:40NASA's Cassini probe reveals Titan in unprecedented detail.
28:47A thick, dense atmosphere.
28:50Vast mountain ranges.
28:52Lakes of liquid methane.
28:56And this.
29:00An arrow-shaped band of white methane clouds moving over its surface.
29:07When the clouds drifted over a dusty open plain, seen here as a dark patch,
29:14the dark patch of ground beneath the clouds grew larger.
29:22Scientists believe liquid methane drenched the surface.
29:28A spring rain storm, Titan-style.
29:37Rain on Titan, if it exists, would be very different from rain on the planet Earth.
29:42First of all, the gravitational field is very weak.
29:45So you would actually see raindrops falling very slowly at you.
29:49Also, the size of these droplets could be much larger.
29:53But don't get caught in a rainstorm on Titan.
29:55Those droplets are awfully cold.
30:00Titan's methane monsoon sweeps across the moon.
30:05Weak gravity creates ultra-cold, hazelnut-sized raindrops.
30:11An alien world with truly alien weather.
30:18These slow drops have carved valleys and lakes, much like ours on Earth.
30:24A slow-motion megastorm.
30:32Fly even farther out through the solar system, and you find storms that are altogether faster.
30:41This is super-chilled Neptune.
30:46The temperature never gets above 300 degrees below zero.
30:52Neptune is one of these giant planets.
30:56It's much larger than the Earth and has a very thick atmosphere.
30:59It's 2 billion miles out from the sun.
31:02So you really might expect, since it's that far from the sun, it would be very cold and not have very much weather.
31:07But in fact, Neptune is very dynamic.
31:10It's got tremendous weather patterns.
31:13Despite its incredible distance from Earth, astronomers can get close to Neptune's turbulent atmosphere.
31:22With a little help from this.
31:25The Keck Observatory, 14,000 feet up on the summit of Mauna Kea in Hawaii.
31:35It sits above Earth's clouds and pollution.
31:42The telescopes are so powerful, they could see a candle on the moon.
31:53Neptune at first appears featureless.
31:59But a closer look reveals white, high-altitude clouds in the upper atmosphere.
32:07It's a perfect opportunity to track wind speed.
32:12Using the time and distance the clouds take between two points allows scientists to clock their speed.
32:23The Keck telescope swings towards Neptune.
32:28A series of shots track the white clouds as they move around the planet.
32:34So here we can take several photographs that show the positions of clouds apparently changing.
32:40You can measure the position at one moment to be there, and at another time, a few hours later, to be in a different place.
32:46Now most of that change in position is due to the rotation of the planet as a whole.
32:51However, if you know the rotation rate and subtract that out, that gives you the motion of the clouds relative to the planet.
32:59That tells you the wind speed.
33:02The results are shocking.
33:05We're seeing wind speeds on Neptune of many hundreds of miles per hour up to 12 or even 1260 miles per hour for the very fastest clouds.
33:16That's really phenomenal.
33:19Neptune has the fastest winds in the solar system.
33:26So what's driving this? You need energy to make weather.
33:30Where's that energy coming from? And it turns out it's coming from Neptune itself.
33:34It does receive sunlight, but Neptune actually radiates away more energy, a lot more energy than it gets from the sun, which means the interior is very hot.
33:44Probably it means there's radioactive material in there.
33:47There's leftover heat from when Neptune formed four and a half billion years ago that's very slowly leaking out.
33:53And it's that that's heating up the air and driving all of the circulation and all of this crazy weather that Neptune has.
34:02Neptune's storms hit hard.
34:09But the search for truly extreme weather takes us out of the solar system altogether into uncharted territory.
34:20Out here, there are storms that make even Neptune's winds look like a breeze.
34:28Katrina was just a sneeze compared to the winds we have on Osiris.
34:35The search for megastorms leads to alien worlds whose violence defies imagination.
34:59Space is full of stars and planets where violence and chaos reign.
35:17Astronomers scour the skies for new worlds, and the king of the planet hunters is Professor Jeff Marcy.
35:27He scans the night sky seeking new worlds around distant stars.
35:38Marcy's team has instruments so sensitive they can even predict the weather on these distant planets.
35:47This is Osiris, 150 light years from Earth.
35:55A planet from hell with matching weather.
36:02Earth is 93 million miles from the sun.
36:07It orbits the sun in one year.
36:12But Osiris is just 4 million miles from its star.
36:18Its year races by in just three and a half days.
36:24When Osiris passes between us and its star, starlight briefly shines through its atmosphere,
36:32giving us a glimpse of conditions on the alien world.
36:38They waited until the planet was in front of the star.
36:43At that moment, some of the starlight passed through the atmosphere of the planet.
36:49They were able to do essentially a chemical assay, a chemical assessment of the composition of this atmosphere.
37:00Osiris gets blasted by the intense heat of its star.
37:07Temperatures top 2,000 degrees.
37:14Now, what that means is that the environment on that planet is, well, hideous for life as we know it.
37:22But even more, the intense heat causes the gases to expand,
37:27and they have no place to go but the backside of the planet.
37:33Osiris is tidally locked.
37:36The same side of the planet always faces the star.
37:40The other looks out into space.
37:44The temperature difference is immense.
37:51Superheated atmosphere roars from the bright side of the planet to the dark at nearly six times the speed of sound.
38:01In fact, the winds will be something like 2,000 or 3,000 miles per hour.
38:07Enormous speeds of these winds, 10 times, 20 times faster wind speeds than the strongest hurricanes.
38:15Katrina was just a sneeze compared to the winds we have on Osiris.
38:24Osiris is a brutal world.
38:28Too hot and too violent for any kind of life we could imagine.
38:41But there are even larger megastorms, storms on the scale of whole galaxies.
38:59And these vast storms may be the reason any of us are here.
39:08The Hubble Space Telescope captured this stunning image of the galaxy NGC 3079.
39:18At its center, a super wind.
39:23A storm on a truly cosmic scale.
39:31It was triggered by an explosion from a forming star.
39:36This raging galactic storm is about 3,000 light years wide.
39:41It has already raged for around one million years.
39:47Filaments of 20 million degree gas tower above the spiral galaxy.
39:56This cosmic megastorm wreaks havoc within its host galaxy.
40:02We see bubbles and jets and formations of gas falling into the galaxy, colliding with galactic dust.
40:11The gas from the galactic megastorm smashes into gas and dust at the heart of the galaxy.
40:19And compresses it into a swirling mass of matter.
40:28Gravity takes over.
40:31The compressed clouds of gas and dust get tighter and tighter.
40:36The center gets hotter and hotter.
40:40Finally it ignites.
40:44Powerful winds from the new star blast into space.
40:49The whole cycle begins over again.
40:53And a new galactic megastorm is born.
40:59Around the fledgling stars, dust and rock come together.
41:05The birth of new worlds with rocky surfaces where life could begin.
41:11And perhaps the formation of life itself may be determined by how these gases swirl and create super galactic storms.
41:19And if you have galactic winds churning away, then that would help to distribute the elements necessary for life throughout the galaxy.
41:28So galactic storms may in some sense be one clue to the formation of life itself.
41:36Galactic megastorms rage for millions of years.
41:43Billions of years ago, they may have created new homes for life in our Milky Way galaxy.
41:52On every scale, storms are not just a force of destruction.
41:57They are linked to creation itself.
42:00The search for life on other worlds is also the search for storms.
42:06When you disrupt the status quo, you open all kinds of possibilities for things to reassemble in different ways.
42:12So chaos or disruption is actually an important factor in the development of complex systems like life.
42:20A planet that might have changes of seasons, volcanism, intense storms.
42:26Some environmental factors that you might think could be damaging to life in the long run makes life stronger.
42:38Earth has storms.
42:40Other worlds have megastorms.
42:44Whether it's lightning on Saturn, the turbulent atmosphere of Jupiter, or blistering temperatures on Osiris,
42:54vast, violent, and deadly megastorms could also be the catalyst for life.

Recommended