An exploration of the dramatic fate of our future descendants, the technology they will need to survive the end of this world billions of years from now, and our options for colonizing a new planet somewhere far from Earth.
Thanks for watching. Follow for more videos.
#cosmosspacescience
#spacedeepestsecrets
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#sunofsun
#solarsystem
Thanks for watching. Follow for more videos.
#cosmosspacescience
#spacedeepestsecrets
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#spacedocumentary
#sunofsun
#solarsystem
Category
đź“š
LearningTranscript
00:00Our Sun, the heart of the solar system, the giver of light, heat, and of course, life.
00:16But what does its future hold?
00:20Scientists are looking to the stars to find out.
00:24Between these two stars is what's going to happen to our Sun.
00:31Scientists today are almost like modern-day prophets.
00:35They foresee an apocalyptic future.
00:39Imagine the ball is Andromeda Galaxy on a head-on collision with the Milky Way Galaxy.
00:45The fate of the Earth hangs in the balance.
00:49Wow, look at this.
00:51The temperature at the surface of the Earth will be enough to melt rock, enough to melt the whole surface of the Earth.
01:00This is the story of how our Sun will transform the solar system it binds together
01:08before bringing it to a spectacular end.
01:15Peoria, Illinois.
01:37Peoria, Illinois.
01:44An average city in Midwest America.
01:49But it has one claim to fame that's out of this world.
01:53In the middle of town, there's a 46-foot-wide mosaic of the Sun.
02:04The centerpiece of a huge-scale model of our solar system, created by local astronomer Sheldon Schaefer.
02:12And here we are at the Sun, and boy is it hot.
02:16It's about 10,000 degrees here at the surface, and over a million Earths could fit inside of the Sun.
02:22Peoria's solar system, 99 million times smaller than the real thing,
02:29accurately reveals the relative sizes of our Sun and its planets.
02:34Okay, we're all together?
02:35And the distances between them.
02:37My job title is curator of the solar system, and we just went 33 million miles
02:46until we got to this tiny little 2-inch Mercury.
02:50All right, so we're headed off to Venus.
02:54From Mercury, the inner planets are strung along a picturesque Riverside Park,
02:59all the way to Mars.
03:01These planets are relatively close together.
03:08The outer planets are much further away, in some bizarre locations.
03:16Five miles from the image of the Sun, above the local airport's check-in desks,
03:22is 5-foot-wide Jupiter.
03:26Well, if you're going to have a planet, you may as well have the biggest one, right?
03:29So, it's fun to have Jupiter.
03:32Occasionally, we have birds that decorate, so we've had to clean it, but not very often.
03:39While the children's section of a neighboring town's library is home to Saturn.
03:52Uranus is in Princeville, Illinois.
03:54From there, it's a 10-mile drive along Route 91, or almost a billion miles in cosmic terms,
04:04to the old railroad depot in Wyoming, Illinois, and Neptune.
04:10And finally, in a furniture store, 40 Earth miles away from the center of the Sun,
04:22in Kewanee, Illinois, is distant Pluto.
04:30Peoria's models are a perfect likeness of the solar system today.
04:34But it won't always be this way.
04:41Scientists know that one day, the Sun will fundamentally change
04:46and transform the planets.
04:50Imagine fast-forwarding through the next 7 billion years
04:58to watch the end of the solar system.
05:07Dr. Eva Villavere can predict this future
05:10because everything that will happen to our Sun
05:16is already happening to countless other stars.
05:22Some, known as solar twins,
05:24are remarkably similar to our own.
05:29We study solar twins because they are very important
05:32to understand not only the Sun,
05:35but to tell us how the future of our own solar system will be.
05:39In 2013, a solar twin called Corazole-1 was discovered.
05:47Corotis over there in the constellation of Monosieros
05:49is a star like the Sun and has the same mass,
05:53exactly the same mass.
05:55But astronomers found one particularly significant difference.
06:00It had a lower concentration of the element lithium,
06:03which helped them to accurately calculate its age.
06:06It's a star that is a little bit older than the Sun,
06:11a few billion years older.
06:13And if we observe a star that is older than our Sun,
06:16we know what will happen to the Sun.
06:20Eva and her team discovered that this older version of our Sun
06:24was giving out more radiation.
06:26So, help us put the pieces together.
06:34As the Sun will get older,
06:36it will become brighter, much brighter.
06:38Our Sun's luminosity is slowly increasing
06:47because of a change deep inside the Sun.
06:54Where two opposing forces are in constant battle.
07:00Similar forces to those that act on a hot air balloon.
07:03pushing up and out is the immense pressure of hot gas.
07:14In the Sun, this is created by nuclear fusion.
07:17The Sun has been burning hydrogen into helium
07:26for thousands of millions of years now.
07:30This is like the propane butter here.
07:32It's like generating heat that warm up the air
07:36that keeps the balloon going.
07:38That's what happens in the Sun, too.
07:39The pulling down into the core of the Sun
07:46is an equally powerful force.
07:50Gravity.
07:51The life of the Sun is nothing but a battle against gravity.
07:55We have the gravitational force trying to pull the star,
07:58crush the star together.
08:00I mean, like pushing it in.
08:01And then we have the thermal pressure of the gas pushing outwards.
08:05So the balance between the two forces
08:08is what keeps the Sun stable.
08:14For four and a half billion years,
08:17the two forces have been in perfect balance.
08:20But as time passes, this balance is shifting.
08:27As the Sun fuses hydrogen,
08:30it produces around 600 million tons of helium every second,
08:34which is a denser gas.
08:39This change in density has a profound effect
08:42on the nuclear reactions.
08:46As the core gets denser,
08:47hydrogen is burned at a higher rate.
08:50It's like turning the burners up.
08:52I mean, we are increasing the energy
08:54that is coming out of the core at that point.
08:58As a result,
08:59our Sun is getting 10% brighter every billion years.
09:04So the older it gets,
09:10the more it heats up the solar system.
09:14And scientists know that
09:16will one day have serious consequences.
09:18The Earth has oceans and clouds
09:33because it orbits a band around the Sun
09:36called the habitable zone,
09:38which means it's just the right temperature
09:42for liquid water.
09:43And that makes it the only planet in the solar system
09:47where we know life can thrive.
09:53But as the Sun becomes more powerful,
09:56the habitable zone will move.
09:58For a vision of the Earth
10:04in two billion years' time,
10:06astrobiologist Professor Lynn Rothschild
10:09believes we should look to Venus.
10:19Venus is up in the sky there.
10:21It's the brightest object after the Sun and the Moon.
10:24It's right near Jupiter this morning.
10:27It's just an absolutely spectacular day to see it.
10:34Venus and the Earth formed out of the same materials.
10:37They're roughly the same size.
10:38The difference is that Venus is closer to the Sun.
10:41It's no surprise Venus is warmer than Earth.
10:47But strangely, Venus is even hotter than Mercury,
10:51despite being further from the Sun.
11:03In 2006, the Venus Express probe
11:06launched towards our nearest planet
11:08to analyze the Venusian atmosphere
11:10in unprecedented detail.
11:17It found a vital clue among the clouds
11:19to how Venus became so hot.
11:24Venus Express allowed us to see
11:27that there was a lot of deuterium,
11:30which is a heavy form of hydrogen left.
11:32And that's indicative of the fact
11:34that there was once water here.
11:35It soon became clear that in the past,
11:39Venus was a very different world.
11:44So here was this beautiful water world,
11:47not too dissimilar to maybe
11:49what the Earth is like today.
11:50There was liquid water
11:52and reasonable atmospheric pressure
11:54and organic compounds.
11:56There's no reason
11:57that there shouldn't have been life.
11:58The evidence suggests
12:10that Venus was once in the habitable zone.
12:15But as the Sun grew brighter
12:17three billion years ago,
12:18it would have had a dramatic effect
12:20on the planet's water.
12:21As the Sun started to get hotter,
12:27the surface of Venus started to get hotter,
12:29and therefore the water turns into steam.
12:32And steam is a greenhouse gas,
12:34so that means it traps the solar radiation.
12:37And therefore, just like a greenhouse,
12:39it starts to get hotter and hotter.
12:43It seems a runaway greenhouse effect
12:46caused Venus to become
12:47the hottest planet in the solar system.
12:51Mercury, although closer to the Sun,
12:56has no atmosphere and no water.
13:01Earth has both.
13:03And as the brighter Sun evaporates our oceans,
13:06the effect is likely to be far more intense
13:10than the man-made global warming we see today.
13:15Over the next two billion years,
13:18temperatures on Earth will rocket.
13:19Life here must adapt
13:23or die.
13:30Yellowstone National Park
13:32is a natural laboratory for Lynn
13:34to study how life can survive
13:36in extreme conditions.
13:37The reason it's so great
13:42is that we have the whole range
13:44from the top predators,
13:45things like wolves and bears and so on,
13:48all the way down to the beavers
13:51and the herbivores
13:52and down to the very tiny organisms
13:54and even some incredible microbes.
14:00Life here is used to dealing with extremes.
14:03But in about a half a billion years' time,
14:07these extremes will go in the opposite direction
14:10as temperatures could climb
14:12by up to 20 degrees in some places.
14:14By then, life as we know it
14:21will have evolved to be very different.
14:26But just as some of today's animals
14:28have adapted to survive harsh winters,
14:31in the future,
14:32they may use similar strategies
14:34to cope with scorching summers.
14:35As the sun gets hotter,
14:38you could imagine the winter
14:40as being the very pleasant season
14:41and the summers become unbearably hot.
14:46So if you're thinking about a bear
14:47that lives in an area like this
14:49that would normally hibernate in the winter,
14:51if you turn the thermostat on the earth high enough,
14:54it might be the reverse
14:55so that now animals would be hibernating
14:58in the summer and be active in the winter.
15:00And grasses would be setting seed now
15:03in the spring.
15:04The seeds would be what would carry the plant
15:06through this harsh summer.
15:08And then as the rain started again
15:10in the autumn,
15:11they would germinate
15:12and you would get the lush green in the winter.
15:19In less than a billion years' time,
15:22the greenhouse effect is expected to take off,
15:26sending temperatures soaring.
15:34As it gets hotter and hotter on the land,
15:38eventually even the winters will be too hot
15:41for most organisms certainly to live.
15:45So if you had a large animal,
15:47like say a bison,
15:49that's also warm-blooded,
15:50as it gets hotter and hotter,
15:52it won't be able to cool down
15:53and it will eventually die.
15:55And so ultimately,
15:59large animals like that will go extinct.
16:02In just over a billion years from now,
16:05the land could be nothing but a parched desert,
16:08devoid of life.
16:11The air is going to heat up
16:12much more quickly than water will.
16:14And so I predict
16:16that just like the ancestors of whales
16:18and dolphins and so on
16:20move from the land to the water,
16:22so will the descendants of bison
16:23if they want to survive.
16:26But models suggest
16:27that in two billion years' time,
16:29even the water will have gone.
16:33As it boils away,
16:35the Earth would increasingly
16:36resemble Venus today.
16:42In less than three billion years' time,
16:45it's thought that the searing sun
16:47and a runaway greenhouse effect
16:49will have wiped out
16:50virtually all life on Earth.
16:53But intelligent life
16:55may just find a way out.
16:59We have something
17:00that the other organisms
17:01out there don't have,
17:02and that is we have technology.
17:04And we're going to have the option
17:06of going to other planets.
17:07As it gets too hot for the Earth,
17:09Mars will start to warm up.
17:11And so that means
17:13that it's just possible
17:15Mars will become
17:16a better place for life.
17:17Who knows?
17:18I have great faith
17:18in our descendants.
17:20By then,
17:21Mars is expected
17:22to be in the habitable zone.
17:24So it could provide a refuge,
17:27but not forever.
17:30Because the next threat
17:31will be the entire solar system.
17:33from a hundred billion stars
17:41racing towards us,
17:42the Andromeda galaxy.
17:52Scientists have long suspected
17:54it will one day crash
17:55into our galaxy,
17:57the Milky Way.
17:58But until recently,
18:03no one had been able
18:04to say for sure.
18:19In 2012,
18:21Dr. Tony Sohn
18:22stepped up to the plate.
18:24He and his team
18:26set out to precisely measure
18:27Andromeda's path
18:29and discover if it would be
18:31a near miss,
18:32a glancing blow,
18:34or a head-on hit
18:36with our galaxy.
18:38To predict the outcome,
18:40he used a technique
18:41familiar to baseball players.
18:43I've got a thought experiment
18:45that can help explain
18:46how he measured
18:46the motion of Andromeda.
18:48Imagine a game of baseball.
18:50The batter is waiting
18:51for the ball
18:52thrown by the pitcher.
18:55To work out
18:56if the ball is on target,
18:57the batter needs to see
18:59whether it's drifting
19:00to the side or not.
19:02So they instinctively
19:03compare the motion
19:04of the ball
19:05against the background.
19:09Tony needed to apply
19:11the same principle
19:12to discover
19:12if Andromeda
19:13was heading towards us.
19:16But in order to measure
19:17the galaxy's motion,
19:19he had to find
19:20fixed points
19:20behind Andromeda
19:22to compare it to.
19:23a daunting task.
19:27Most of the stars
19:28we see on the sky
19:29are in our galaxy,
19:31so they cannot be used
19:33as background objects.
19:36Instead,
19:37Tony had to search
19:38for distant galaxies
19:39hundreds of millions
19:40of light-years away.
19:42Only one telescope
19:43was up to the task.
19:45We used the Hubble Space Telescope
19:48to do this project
19:48because we need
19:51a very stable instrument
19:52and we need to be
19:53above the Earth atmosphere
19:55to get very high resolution
19:56of the image.
19:58With data from Hubble,
20:00Tony painstakingly
20:01tracked stars
20:02in Andromeda
20:03against distant galaxies,
20:05just like a batter
20:07tracks a ball.
20:08Imagine the ball
20:11is Andromeda galaxy
20:12and the fence behind that
20:14are background galaxies.
20:16And what we did
20:17was we compared
20:18the position
20:19of the Andromeda galaxies
20:20against the background galaxies
20:22over time
20:22and that's how we measure
20:23the sideways motion.
20:25The results
20:27were conclusive.
20:30The sideways speed
20:31of Andromeda
20:32we measured
20:32was effectively zero.
20:34So we can say
20:35with certainty
20:36that Andromeda
20:37is on a head-on collision
20:38with the Milky Way galaxy.
20:41Tony's team confirmed
20:43that over 100 billion stars
20:45are on course
20:46for a strike
20:47at 2,000 times
20:49the speed
20:50of a fastball.
20:54But since it's
20:56so far away,
20:57the galaxies won't collide
20:58until nearly
20:594 billion years
21:00from now.
21:05Tony's precise measurements
21:06allow him
21:07to predict
21:08to predict
21:08how this clash
21:09of the titans
21:10will look.
21:13To anyone on Earth,
21:14it would be
21:15a spectacular sight.
21:18We'll see
21:19the Andromeda galaxy
21:20getting bigger
21:21and bigger on the sky
21:22and then eventually,
21:23in about 4 billion years
21:24from now,
21:25we'll see the collision
21:26of the two galaxies.
21:27on impact,
21:36clouds of dust
21:37will be crushed together
21:38with sensational results.
21:44What we'll see
21:45is a lot of stars
21:46getting formed
21:47and this will look
21:48something like
21:49stellar fireworks
21:50on the sky.
21:50Tony can even calculate
22:00the odds
22:01that our solar system
22:02will crash
22:02into one of Andromeda's
22:04billions of stars
22:05during the collision.
22:09Surprisingly,
22:10the prognosis is good.
22:13Galaxies are essentially
22:14empty space,
22:15so the chances
22:16of stars colliding
22:17with another star
22:18is very slim
22:20because the distance
22:21between the stars
22:22is vast.
22:23So when the collision
22:24happens,
22:24the solar system
22:25will pass through
22:26an empty space
22:27between the stars.
22:33After passing
22:34like ghosts
22:34in the night,
22:36the irresistible
22:37pull of gravity
22:38will draw them
22:39back together
22:40over the next
22:402 billion years
22:41to finally settle
22:44as a new
22:44supergalaxy
22:45nicknamed
22:46Milkomida.
22:52Our galaxy
22:53will no longer exist,
22:56yet calculations
22:57suggest
22:58the solar system
22:59will survive.
23:02It will merge
23:03into one big galaxy
23:05and it will look
23:06like a giant ball
23:07on the sky.
23:10Sadly,
23:11it's unlikely
23:12anyone will be
23:13on Earth
23:13to witness
23:14this colossal
23:15galactic collision.
23:20But there's
23:21a slim chance
23:22an extreme form
23:23of life
23:24could be clinging on
23:25as the two galaxies
23:27meet,
23:29despite the searing heat
23:30from the aging sun.
23:37In Yellowstone,
23:38Professor Lynn Rothschild
23:40has found evidence
23:41of what those
23:42last remaining
23:43Earthlings
23:43might be like.
23:46This area
23:47of Yellowstone
23:48is extremely acidic
23:49and it's also hot.
23:51You can see
23:51the steam rising.
23:52So in other words,
23:53it's sort of like
23:54boiling battery acid.
23:56Very few living things
23:57can actually live
23:58at this high temperature,
24:00but there are
24:01a couple of organisms
24:02that are very well
24:03adapted for it.
24:04You can see
24:04the beautiful colors
24:05behind me.
24:06The kaleidoscope colors
24:10of Yellowstone's springs
24:12are caused
24:12by heat-loving microbes.
24:21We can pretty much
24:22use these
24:23as a thermometer.
24:24Anything that is green
24:26means that it's got chlorophyll,
24:28just like plants,
24:29and once they get
24:30to a temperature
24:31above about 73 degrees
24:33or so,
24:34their chlorophyll
24:34breaks down.
24:36And so when you start
24:37getting warmer than that,
24:38you start to move
24:39into other sorts
24:40of organisms,
24:41organisms that,
24:42for example,
24:42eat iron.
24:43And then you see
24:44these beautiful
24:45orange colors.
24:46Once all the water
24:48on Earth
24:48has turned to steam,
24:50it's possible
24:50that heat-loving microbes
24:52could continue to live
24:53in the clouds.
24:58We know some
24:58of the earliest organisms
25:00on the Earth
25:00were thermophiles,
25:02organisms that lived
25:02at high temperature.
25:04And so at some point,
25:05it may be organisms
25:06like this
25:06that once again
25:07inherit the Earth.
25:11The microbes
25:12will have their day,
25:14but their rain
25:15will inevitably
25:16be cut short.
25:21Because when the sun
25:22is twice the age
25:23it is now,
25:24astronomers foresee
25:26a turbulent new phase
25:28written in the stars.
25:43On a clear night,
25:44many of the stars
25:45you can see
25:46with your naked eye
25:47today are going
25:48through a phase.
25:50You can tell
25:51which ones they are
25:52because of their color.
25:54They're known
25:55as red giants.
26:00It's very easy
26:01to see red giant stars
26:02because they are
26:02very bright.
26:03They are giant
26:04and they are bright.
26:05So they are everywhere
26:07in the sky.
26:08Some red giants
26:09are so large
26:10you could fit
26:11our own sun
26:12inside them
26:12millions of times over.
26:16Yet astronomers
26:17are confident
26:18our sun
26:19will one day
26:20will one day
26:20grow to become
26:21one itself.
26:23So these stars
26:24are a glimpse
26:25of our future.
26:30If we study stars
26:31that grow in size,
26:32we can tell
26:33the fate
26:33of the planetary systems
26:35that are orbiting them.
26:36Stars like that
26:37give us already
26:38clues about
26:38what will be
26:39the future fate
26:40of our own
26:41solar system.
26:42The transformation
26:47of our sun
26:48into a red giant
26:49will begin
26:50deep below its surface
26:51where all the heat
26:52is generated.
26:58The burning core
26:59is the only place
27:00hot enough
27:00for hydrogen
27:01to fuse
27:02and yet it makes up
27:04less than 2%
27:05of the sun's
27:06total volume.
27:07For the next
27:105 billion years
27:11it's thought
27:12the core
27:13will be stable
27:14finely balanced
27:16between two
27:17phenomenal
27:18opposing forces
27:19the crushing
27:21pull of gravity
27:22and the explosive
27:26push of nuclear
27:27heated gas.
27:31But like a hot air
27:33balloon,
27:33the core
27:34will eventually
27:35run out of fuel.
27:37just as gravity
27:39pulls the spent
27:40balloon down
27:41in the sun
27:42gravity would
27:44pull on the core.
27:48When the balance
27:49is broken
27:50because the hydrogen
27:51runs out in the core
27:53the dominant force
27:53will be gravity.
27:55It will try
27:55to squeeze the core.
27:57But the sun
27:58will be far
27:59from spent.
28:00As gravity
28:01crushes the core
28:02it will trigger
28:03a transformation
28:04in the rest
28:05of the sun.
28:07For the first
28:08time
28:08the hydrogen
28:09gas surrounding
28:10the core
28:11will begin
28:11to fuse
28:12giving the sun
28:15access
28:15to far more
28:16fuel
28:17than it's
28:17already burnt.
28:19We ran out
28:20already of one
28:21bottle of propane
28:22but we have
28:23three more.
28:25It's like
28:26the sun.
28:27The burning
28:32shell of hydrogen
28:33releases so much
28:34heat
28:35that gravity
28:36is overwhelmed
28:37tipping the
28:39balance in favor
28:40of rapid
28:41expansion.
28:43Gravity
28:43is not winning
28:44the battle
28:44so
28:45the star
28:46expands
28:47as a red giant.
28:48astronomers predict
28:54that in about
28:55five billion years
28:56the sun will
28:57start to grow
28:58into a vast
28:59seething ball
29:00of fire.
29:04A red giant
29:05sending temperatures
29:09soaring across
29:10the solar system.
29:11The inner planets
29:15will become
29:16far too hot
29:17to support
29:18any kind
29:18of life
29:19but the distant
29:20outer planets
29:21will bask
29:23in the warm
29:24glow of the sun
29:25for the first
29:25time.
29:29The habitable
29:30zone
29:31where life
29:32can exist
29:33will sweep
29:34out.
29:39In Peoria's
29:40solar system
29:41model
29:41it would have
29:42meant the
29:42habitable zone
29:43would leave town
29:44and head
29:45for the outskirts.
29:51Here at the
29:52airport
29:52is Jupiter.
30:00When the sun
30:01grows
30:02Jupiter
30:03will come in
30:04from the cold
30:05and although
30:09life as we know
30:10it could never
30:11survive on
30:12gassy Jupiter
30:12the solar system's
30:14biggest planet
30:15has several
30:16icy moons.
30:20These are likely
30:21to melt
30:21and become
30:22cosmic watering
30:23holes for any
30:24refugees fleeing
30:25the parched
30:26inner solar system.
30:30Astronomers
30:30have speculated
30:31that Jupiter
30:32could change
30:33of color.
30:37As clouds of ammonia
30:38vaporize
30:39it might turn
30:40into a deep
30:41shade of blue.
30:48After Jupiter
30:49astronomers expect
30:50the habitable zone
30:51to move swiftly
30:52toward Saturn.
30:53If Saturn
30:58still has
30:59its icy rings
31:00by then
31:00they're forecast
31:01to vaporize
31:02and disappear.
31:10But like Jupiter
31:11Saturn's icy moons
31:13could melt
31:13and be safe havens
31:15for life.
31:16then models
31:25predict the
31:26habitable zone
31:27will sweep
31:28out faster
31:29and faster
31:29past the
31:31solar system's
31:31most distant
31:32planets
31:33and their moons.
31:35First Uranus
31:36then deep blue
31:44Neptune.
31:48Astronomers
31:49think
31:49they too
31:50will be
31:50transformed
31:51but exactly
31:52how they'll
31:53look in the
31:53future
31:54is still
31:55a mystery.
31:59Eventually
32:00the habitable zone
32:01is forecast
32:02to pass
32:03beyond all
32:04the planets
32:05and their moons.
32:08Although Neptune
32:10is the final planet
32:11the solar system
32:12doesn't finish
32:14there.
32:27In July
32:282015
32:29the New Horizons
32:31mission
32:31finally revealed
32:33Pluto's secrets.
32:40The first clear
32:41images ever
32:42captured
32:43of the dwarf planet
32:44revealed
32:45some startling
32:46terrain
32:47strange troughs
32:50cliffs
32:51and even dunes.
32:58After a 12 billion
33:00year long winter
33:01the expanding sun
33:03may bring spring
33:05to Pluto.
33:05Pluto
33:09but while the red giant
33:12nurtures Pluto
33:13it poses a grave threat
33:17to the planets
33:18of the inner solar system.
33:20They face
33:21total annihilation.
33:29Studying the night sky
33:30Dr. Eva Villavere
33:33uncovered grisly evidence
33:34of what red giants
33:36can do to their
33:36inner planets.
33:39A search for distant worlds
33:41had led to the
33:42constellation of Perseus
33:44where a star called
33:45BD plus 48740
33:48caught her attention
33:49for two reasons.
33:51There we have a star
33:55a red giant
33:56that was very peculiar
33:58because the star
33:59itself has a very
34:00high content
34:01in lithium
34:01and that's very
34:02unusual for this
34:03type of star.
34:05So that was
34:06one of the pieces
34:07of the puzzle
34:08and the other one
34:09was that it has
34:10a Jupiter-like planet
34:12orbiting the star
34:13that has an orbit
34:14that is very unusual.
34:17Eva thought
34:17the two strange features
34:19must be somehow connected.
34:22Something had happened
34:23that had affected
34:24both the planet
34:25and the star itself.
34:30In around
34:31five and a half
34:32billion years
34:33our own sun
34:35will enter
34:35this extraordinary
34:36phase of its life.
34:40Evidence suggests
34:42its surface
34:42will reach out
34:43towards Mercury,
34:44Venus and Earth
34:45threatening their
34:47very existence.
34:51Local astronomer
34:52Sheldon Schaefer
34:53is leading his weekly
34:54interplanetary bicycle tour
34:56with the sun's surface
34:58hot on his heels.
35:01And here we are
35:02approaching Mercury.
35:07You can see
35:08it's easily
35:09a stunt double
35:10for the Earth's moon.
35:11It's a heavily cratered
35:13world without an atmosphere,
35:14hot in the sun
35:15and cold in the darkness.
35:17But the solar system's
35:19smallest planet
35:20will get hotter still.
35:22Off to Venus!
35:24Because astronomers predict
35:25that less than a billion years
35:27into the red giant phase
35:29the sun's surface
35:31will reach Mercury.
35:35After more than
35:3610 billion years
35:37of relative calm
35:38the solar system
35:40will lose a planet
35:42will lose a planet
35:42and the sun
35:50will continue
35:51to expand
35:51growing ever closer
35:56to Venus.
36:01The next planet
36:02is Earth.
36:06By the time the sun
36:10engulfs Venus
36:11the Earth's oceans
36:13are expected
36:14to have boiled away.
36:18The ultimate fate
36:19of our world
36:20appears to be
36:22on a knife's edge.
36:23For a vision
36:32of those final days
36:34on Earth
36:34Dr. Eva Villavere
36:36has come to
36:36a unique facility
36:38in Odielo, France
36:39the world's largest
36:42solar furnace.
36:43As the sun
36:48becomes a red giant
36:49we will have
36:50a red star
36:51occupying most
36:52of the sky
36:53and the energy
36:55that every single
36:56inch of the Earth
36:57will receive
36:57will increase.
36:59And here
36:59this is exactly
37:00what these mirrors
37:01are doing.
37:03Around 10,000 mirrors
37:05focus the sun's rays
37:07like a giant
37:08magnifying glass
37:09which allows them
37:11to replicate
37:12the conditions
37:13the Earth
37:14will face
37:14when the sun
37:15becomes a red giant.
37:32Dr. Eva Villavere
37:33is calculating
37:34the temperature
37:35of the Earth's surface
37:36when the sun's radiation
37:37will be nearly
37:383,000 times
37:39more intense
37:40than today.
37:43So, to simulate
37:47our future
37:48the solar furnace
37:49has magnified
37:51the sun's power
37:52by 3,000 times.
37:56We are focusing
37:57the light
37:58of the sun
37:59in a beam
37:59and trying to see
38:00what will be the effect
38:01on a rock
38:02because the Earth
38:03is a rock
38:04floating around the sun.
38:05Wow, look at this.
38:21There it goes.
38:22The temperature
38:29at the surface
38:30of the Earth
38:30at that point
38:31will be of the order
38:32of 1,400 degrees
38:35enough to melt rock
38:36enough to melt
38:38the whole surface
38:38of the Earth.
38:44It's thought
38:45the planet
38:45will be covered
38:46in a vast ocean
38:47of molten lava.
38:48But even after
38:52the Earth's surface
38:53is melted
38:53the heat
38:54is expected
38:55to increase
38:56further
38:56as the planet
38:57is engulfed.
38:59The maximum
39:00intensity
39:01of the solar furnace
39:02is 16,000 times
39:04the sun's power
39:05today.
39:08Still
39:09only a fraction
39:10of what the Earth
39:11would encounter
39:12inside the red giant.
39:13the rock
39:16would be stripped
39:17away
39:17leaving just
39:19the planet's
39:19iron core.
39:29Wow, look at this.
39:32Just
39:33sun radiation.
39:35That's
39:36iron being
39:37merged
39:37by the radiation
39:38of the sun.
39:40This is how
39:41the last moments
39:43of our world
39:43would be.
39:46So everything,
39:47the whole material
39:48of the Earth
39:49will melt
39:49all the way
39:50down to the core.
39:51Even the iron core
39:51will melt.
39:53And the whole material
39:54of the Earth
39:54will be part
39:55of the material
39:55of the sun.
39:56Everything will be
39:57mixed together.
39:59According to
40:00the latest calculations,
40:02the world
40:02will end
40:03in fire.
40:08But our
40:09solar system's
40:10story is not
40:11quite over yet.
40:13because the
40:13final phase
40:14of the sun's
40:15life will be
40:16the most
40:16spectacular
40:17of all.
40:21There's seven
40:21sisters.
40:22It's like an
40:22upside down
40:23L.
40:23Nick, you wanted
40:24to see the
40:24Andromeda?
40:25It's really cool.
40:27Wow.
40:29In Peoria,
40:29every Saturday
40:30night,
40:31the Astronomy
40:32Society meets
40:33by the Northmore
40:34Observatory
40:35at the edge
40:36of town.
40:36Between these
40:38two stars
40:39is the remnant
40:40of what's
40:41going to happen
40:42to our sun.
40:44So we're
40:45going to move
40:45the telescope
40:46and Brian,
40:47do you want
40:47to move the dome?
40:49Tonight,
40:50Sheldon is
40:51searching for a
40:52distant dying star,
40:54the Ring
40:56Nebula.
40:56Okay, that's
41:00good, Brian.
41:02Ah, I think
41:03it's there.
41:06Okay, so
41:07come on over
41:08and take a look.
41:09Look through the
41:10eyepiece, and
41:11you should see a
41:12lot of stars, and
41:12then right in the
41:13middle, do you see
41:13that little smoke
41:14ring?
41:15Yeah.
41:16It's just barely
41:16there, right?
41:17Yeah.
41:18Wow.
41:19So this is a star
41:20that after the
41:21red giant stage,
41:24it puffs off
41:25shells of itself.
41:26It expels most
41:27of its matter
41:28into like
41:29bubbles of gas.
41:31The planetary
41:32nebulae produced
41:33by dying stars
41:35are some of the
41:36most spectacular
41:37celestial objects
41:38in the night sky.
41:40When our sun
41:41dies, it too
41:43could make a
41:44nebula.
41:46Astronomers
41:47have calculated
41:47that up to half
41:49of the sun's
41:49mass could be
41:50thrown off into
41:51space as gas
41:52and dust, including
41:55much of the
41:56material that
41:57came from the
41:57earth.
42:00The vaporized
42:01remains of half
42:02the solar system
42:03would glow
42:04brilliantly for
42:05around 10,000
42:06years.
42:11Then, as it
42:12spreads into
42:13space, the light
42:14would slowly fade.
42:19and our solar
42:19system will end.
42:26But in a sense,
42:28it's just a new
42:29beginning.
42:30The materials that
42:35make up our bodies
42:36may well ultimately
42:38get spit out
42:39into the cosmos
42:41and be the raw
42:42materials for another
42:44generation of stars,
42:46planets, and maybe
42:47even life forms.
42:48We're all famously
42:53made of star
42:54stuff.
42:57And one day,
42:59we may return
43:00to a star.
43:02Our sun.
43:06But then,
43:08in an extraordinary
43:09process of cosmic
43:10rebirth,
43:12the sun would return
43:14our atoms to
43:16interstellar space
43:17to form new
43:20worlds
43:21and perhaps
43:24new life.
Be the first to comment