- 5/10/2025
Exploring new discoveries that rewrite the history of the solar system, revealing a complex and violent story that begins with the birth of the sun from the debris of a massive galactic collision to its eventual fate as a lone zombie star.
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LearningTranscript
00:00:00a small black star floats through space this is the sun billions of years in the future
00:00:10it's all that remains of our solar system the sole survivor of a dramatic history of elegant beauty
00:00:19and extreme violence just because things look really nice and serene now doesn't mean it's
00:00:27always been that way there are a lot of planets that could have made it but didn't and we just
00:00:35happen to be one of the lucky ones that did the players in our solar system story are more tangled
00:00:42up than we ever imagined the more we look at this stuff the more we realize that everything affects
00:00:48everything else including us how did we go from a vibrant family of planets orbiting the yellow sun
00:00:56to a lone dead zombie star
00:01:16it's an old familiar story
00:01:18a bunch of planets orbit a yellow star in a quiet suburb of the milky way galaxy
00:01:29but it's not the whole story
00:01:32over the past decade our vision of our solar system has been completely revamped
00:01:39think of the solar system as an old-fashioned mafia crime family
00:01:44the sun is the dawn his quarreling children the planets their story like any good mob movie is an
00:01:52epic tale of empire building sibling rivalry greed and ultra violence
00:02:00the origin of the solar system was chaotic and violent planets colliding plants even changing places
00:02:06now a shift in our understanding reveals a tale of tangled alliances between family members
00:02:18just think about how much our view of the solar system has changed the planets used to be so
00:02:23far away from each other and of course they had nothing to do with each other and now the history is
00:02:27all about the interaction so the idea that everything is just its own world and doesn't interact is
00:02:34completely wrong we like to think of astronomy as looking up looking outward away from ourselves
00:02:40but the more we do that the more we realize how connected we are to everything out there
00:02:46you probably have some material in your body from pretty much
00:02:49every world that ever existed in the solar system
00:02:53like any good mobster movie our story starts with the humble rise of the godfather
00:02:59in this tale that's the birth of the sun but exactly how that happens is a mystery
00:03:08when we're trying to figure out how the solar system began you know we don't have a
00:03:12time machine so what can we use to find out about how it formed
00:03:19the solar system has the answer its own time machines meteorites
00:03:28meteorites are pieces of the solar system from the distant past and they've remained unchanged since
00:03:35then so they're like little time capsules
00:03:41they're like fossils from before our solar system even formed
00:03:45by studying them we can really study what was happening what was going on in the very early days of our own solar
00:03:51solar system
00:03:542020 scientists study ancient material trapped inside a meteorite found in murchison australia
00:04:04the murchison meteorite contains tiny crystals called pre-solar grains that predate our sun
00:04:11and trapped within them is evidence of the history of the formation of our solar system
00:04:22the pre-solar grains are made up of elements like silicon that form inside giant stars
00:04:33when these stars die they blow out huge clouds of gas and grains of dust
00:04:38the term pre-solar grain doesn't sound very romantic but actually we might call those
00:04:45star dust because these materials are things that were made in stars that no longer exist
00:04:51the murchison meteorite contains grains from at least 46 different stars
00:04:58what the murchison meteorite tells us is that the material that came together that formed our solar system
00:05:04had its origination in dozens of different stars these stars died and blew out all of these materials
00:05:13and then created this huge cloud of gas and dust called a nebula the sources of the material in that
00:05:20cloud could come from one of a number of places the material from lots of stars atmospheres could be mixed in
00:05:27there in the mix were the ingredients to build the solar system but we don't know what triggered the gas
00:05:36and dust to form the sun a 2020 study may have the answer one of the coolest things we've discovered
00:05:46in the last couple decades about the milky way is there's a giant stream of stars that's stretching
00:05:51across virtually the whole sky these stars were not born in the galaxy they're not from here
00:06:02if not from our galaxy then from where we think these stars actually came from the sagittarius dwarf
00:06:12galaxy which orbits the milky way over five billion years ago the sagittarius dwarf galaxy
00:06:20wanders too close to the milky way our galaxy's powerful gravity drags sagittarius towards it
00:06:30the galaxies collide as this is happening the milky way is tearing sagittarius apart ripping stars out of it
00:06:41this is truly intergalactic cosmological drama at play
00:06:46this collision shakes up the milky way when a body passes through the disk of our galaxy
00:06:56it's going to set off ripples and that's going to compress the gas clouds and that's going to create
00:07:01star formation the sagittarius dwarf smashing into the milky way is like dropping a boulder into a pond
00:07:09it sets out ripples of density and it disturbs everything in the galaxy but it doesn't disturb
00:07:23everything equally it causes some clumps of dust and gas to start accumulating together
00:07:34the disruption in one galactic zip code leads to new activity in others across the milky way
00:07:39the ripples trigger gas and dust left over from the dying stars to split into clumps
00:07:48sparking a frenzy of star formation look if you were an observer suddenly out of these little clumps
00:07:56of gas come bright ignition sparks all at once
00:08:00if you were to stand there long enough watching this stellar nursery it might look kind of like
00:08:10a field at night with fireflies blinking on
00:08:14perhaps the sun formed in this starburst
00:08:19the passage of the sagittarius dwarf through our galaxy correlates in time to the formation
00:08:25and birth of our sun so maybe our solar system came about as a result of the sagittarius dwarf
00:08:33passing through our galaxy over five billion years ago
00:08:36of course we don't know for sure if this is what triggered the formation of our sun but the timing does
00:08:42fit
00:08:454.6 billion years ago part of the cloud seeded with material from dying stars grows denser
00:08:55until it gets so massive it collapses
00:08:58as the gas cloud collapses it gets hotter and hotter and spins faster and faster forming a dense core
00:09:09at its center the core is the protostar that will later become our sun
00:09:17the protostar drags in more and more gas and dust creating a region of material spinning around it
00:09:24called the protoplanetary disk as the sun builds up more mass it's getting compressed gravitationally
00:09:33and so the core is getting hotter and hotter and hotter the densities are increasing
00:09:40the new don the head of our solar mobster family immediately reveals a ferocious nature
00:09:48blasting out supercharged jets of radiation
00:09:51the early sun was not the calm glowing orb that we see in our sky today it was far more chaotic
00:10:03it's sort of like in its toddler phase it was acting up all the time
00:10:10it has all of this energy that pushes material off of the surface and launches it into what we call the
00:10:15solar wind the blizzard of particles races out at over a million miles an hour it smashes into the
00:10:25protoplanetary disk and blows the gas away at the same time the sun's core heats up to 18 million degrees
00:10:36fahrenheit triggering the fusion of hydrogen into helium and that releases a tremendous amount of energy that
00:10:44eventually works its way back to the surface of the star and comes out as light
00:10:51finally the sun becomes the recognizable sun that we see in our sky today
00:10:58the sun is now the godfather pulling the strings of the solar system
00:11:05the young dawn's rise to the top triggers a power struggle with its willful children
00:11:10the planets it's a brutal fight for survival
00:11:264.6 billion years ago
00:11:30our mob family rises in a quiet suburb of the milky way
00:11:34its godfather the sun forms from a collapsed stellar nebula
00:11:45the greedy star scarps down most of the cloud of gas and dust but just enough is left over to build
00:11:52the planets we're standing here on a big planet and we look up in the sky and we see other planets going
00:11:58around the sun and it's an obvious and challenging question to ask where did these planets come from
00:12:06how did the leftover gas and dust build the planets
00:12:12to solve the mystery scientists study other star systems across the milky way
00:12:17we can't go back in time and watch our own solar system forming but we can look at other new solar
00:12:24systems as they're forming and use that to understand how our own might have formed
00:12:34star system pds-70 is one such system
00:12:41it's young just 5.4 million years old
00:12:47and nestled inside the protoplanetary disk are two infant planets feeding on gas and dust
00:12:58we can see these baby exoplanets pulling in material and creating these gaps in the disk
00:13:03it's an amazing discovery it's kind of mind-blowing that we can see a new solar system being born
00:13:09these snapshots these systems like pds-70 are so valuable because they let us test our theories
00:13:18we thought planets formed from these disks of dust and gas but we hadn't seen it until now
00:13:24what we couldn't see was how gas and dust bind together to grow into planets
00:13:29that took an astronaut on the space station messing around with breakfast
00:13:44don pettit this one astronaut took a bag full of salt and sugar and coffee ground and just shook
00:13:49it to see what would happen in zero g and to his astonishment he saw that they immediately clumped
00:13:56up it's effectively electrostatic forces that are causing those clumps to form the salt grains rub
00:14:03around with each other and they develop a charge an electrical charge and so those clumps very naturally
00:14:10form these clumps were strong they didn't fall apart when they hit the sides of the bag and sitting down
00:14:21on the ground down at mission control was astronaut stan love going oh my god don you've solved the first
00:14:27steps of planetary formation a very similar process went on in the early protoplanetary disk instead of salt
00:14:37it's mineral grains so the dust grains that you start with stick to each other because of electrostatic
00:14:48forces basically static cling and it's almost exactly identical to how a dust bunny forms in your room
00:14:54these are cosmic dust bunnies that will someday grow up into giant planets astronomers call these cosmic dust
00:15:03dust bunnies pebbles
00:15:08we think clumping dust particles formed trillions of pebbles each around an inch in diameter
00:15:15it's the first step in planet construction
00:15:19the next step in forming a planet involves planetesimals and these are objects that are roughly
00:15:24half a mile to a hundred miles in size
00:15:26but how pebbles build planetesimals was a mystery because pebbles don't play well together
00:15:38grains of protoplanetary materials stick together because of static charge
00:15:42the problem is once they get too big that force isn't enough and they'll just bounce off each other
00:15:47yet we know that we have to to get all the way up to hundreds of miles across to build our planetesimals
00:15:59how do you build a bigger structure when the particles that you're trying to lump together are
00:16:04bouncing off of each other
00:16:05so a new idea came forward about how to make this big jump from pebble sized things all the way up to
00:16:13planetesimals and this relies on the interaction of a huge number of pebbles moving together through the
00:16:19gas around the stock
00:16:22in the disk of gas and dust that encircles the young sun pebbles will begin to coalesce into these big
00:16:30clouds much in the same way that individual fish will form schools of fish more and more pebbles join
00:16:40the cloud eventually you get enough of them together that they collapse under their own gravity and make
00:16:47one big planetesimal
00:16:59the planetesimals face a race against time to grow into planets they must grab enough building
00:17:07material from the protoplanetary disk before their dawn the sun blasts it all away
00:17:174.6 billion years ago a fierce battle erupts between the head of the family the sun and his children
00:17:34the growing planets the godfather is armed and dangerous and threatening to destroy the planet's
00:17:41food source with his weapon of choice the solar wind there's this strong wind of high energy
00:17:49particles coming out of the sun that blows away the disk of gas the planets must fight to grab hold of
00:17:57the remaining resources before the sun drives them away so it's a race against time jupiter is racing
00:18:07the sun to capture as much material as it can before the sun blows it all away and what we see from
00:18:13studying other solar systems is that those discs only last for about five million years we used to think
00:18:20of the solar system's protoplanetary disk like an old school diner where the mob family came to eat
00:18:27the firstborn child jupiter grows by wolfing down planetesimals followed by a second course of gas
00:18:34the old model of planet formation is the idea that these large-ish planetesimals that are miles across
00:18:43collide and stick to each other kind of like modeling clay until you get a bigger and bigger object that
00:18:48can eventually get so massive that it starts to then pull in the more diffuse gas around it
00:18:52to form a gaseous atmosphere it's a simple idea but with a big problem time by that old model it would
00:19:02take upwards of 100 million years to accumulate enough planetesimals to do that way too long for
00:19:09jupiter to grow before the sun blows all the gas away we found a clue to how jupiter beat the problem
00:19:18of the disappearing gas in 2017 when the juno spacecraft investigated the gas giant's core
00:19:27the traditional theories predict that jupiter's core would be kind of like a big ball of solid
00:19:32iron or rock surrounded by a giant gaseous atmosphere
00:19:40juno instead found that jupiter's core is fuzzy there's no boundary between hard rock and then
00:19:48gaseous atmosphere there's just a gradual transition as you move outwards from mostly rock and icy to
00:19:55mostly gassy this fuzzy transition from rock ice core to gas suggests that young jupiter didn't eat
00:20:04a la carte with separate courses of planetesimals and then gas
00:20:11instead it devoured the whole buffet in one sitting these fuzzy cores suggest that as jupiter's core was
00:20:21forming it was actually incorporating a mixture of gas and ice and rocks all together in its formation
00:20:28this was possible because there was still lots of gas in the protoplanetary disk
00:20:36everything was moving through this very thick disk of dust and gas that means that everything was
00:20:42actually being slowed down by the drag things were the size of pebbles they were feeling the drag too
00:20:48that meant they lost energy and made it easier for jupiter to pull them in
00:20:54the young planetesimals grab millions of pebbles along with lots of gas
00:21:00they're drawing in gas as well as these pebbles well the pebbles basically run out and they keep
00:21:06drawing this gas in and get bigger and bigger and bigger this formation model allows you to grow
00:21:13a planet like jupiter much more quickly because it's gobbling up everything at once at a very rapid
00:21:18pace and that allows it to potentially beat the sun and grow within a few million years before the sun
00:21:24blows everything away both jupiter and saturn won their race against the sun and grew large
00:21:33but the inner planets were not so lucky the godfather ruthlessly limited the food on their menu
00:21:45and so the planets that formed depend upon what you have to begin with if if you're making a cake and
00:21:51you only have certain ingredients you can only make a cake out of those ingredients and the planets are
00:21:56the same way they could only be made out of things that are in their vicinity in the inner solar system
00:22:02were as much warmer volatiles like water and ammonia had evaporated and be blown away so the only
00:22:09materials found here for building planets were rocky metallic materials so the planets that formed in
00:22:17this inner region are rocky planets with metallic cores
00:22:23the ice giants feasted on materials that only survive far from the sun's harmful influence
00:22:29when you get further out the distances that uranus and neptune are at ammonia and methane start to
00:22:37turn into their own frozen ices that's why we call them ice giants because they're formed primarily out
00:22:42of these solid ices and there were plenty of these ices to gorge on the further you are from the sun the
00:22:52less the effect the solar wind has it's a bit like if you're standing next to a fan or if you're right next
00:22:56to it you're really going to feel it you step back a few paces it's not as blowy and so it's the same
00:23:01thing happening in the outer solar system it's not able to strip away the gases in the rock quite as much
00:23:07the ice giants grew to over 14 times the mass of earth
00:23:13the godfather the sun ruthlessly controls the family but firstborn jupiter has grown large
00:23:20he craves power and attempts a hostile takeover of the inner solar system triggering mass murder and mayhem
00:23:41we used to think that all star systems were similar to our own that's because our solar system
00:23:47was the only one we knew it's hard to get a perspective on your home if you've not been
00:23:53anywhere else we thought it was typical but now that we've discovered hundreds of others
00:23:59it's the weird one it may surprise you to learn that we've never found a solar system around another
00:24:04star that really resembles our own with all of these small rocky planets in the middle of the
00:24:08solar system and these these big gas giants farther out
00:24:11we found star systems with super puff planets rocky worlds orbiting tiny red stars giant stars with
00:24:23superheated planets that rain liquid iron water worlds and planets orbiting zombie white dwarf stars
00:24:32but none that look like our home system every solar system we look at ours just look like it's standing
00:24:39off in a corner all by itself the other systems may be very different from our own
00:24:47but they can still show us how the solar system developed
00:24:532021 scientists discover six planets orbiting a small orange star called toi 178
00:25:03they range from just a little bit more massive than the earth about one and a half times to a bit
00:25:07more than seven times the mass of the earth these are called super earths and it turns out these are
00:25:14really abundant out in the universe around 40 of the star systems we've found contain at least one super
00:25:23earth one of the most peculiar aspects about our solar system is that we don't have any super earths we see
00:25:30these things everywhere not here the first clue to solving the mystery of the missing super earths
00:25:40comes from an asteroid called psyche it orbits in the asteroid belt a band of rocky objects between mars and
00:25:49jupiter the asteroid psyche appears to be a fascinating world made almost entirely of metal of iron and nickel
00:25:57we think it's the core of a now destroyed planet you can think of psyche as a metallic kernel of a nut
00:26:08whose shell was smashed off in a huge collision
00:26:11the asteroid belt is full of similar debris like blood splatter at a mafia murder scene
00:26:29it points to serious felonies taking place in the early solar system
00:26:32we think that there were once dozens of rocky protoplanets orbiting around the young sun
00:26:44now we only have four
00:26:48we find clues to what caused this planetary homicide in distant star systems
00:26:55the first exoplanets that we found orbiting stars like the sun are what we call hot jupiters nobody
00:27:01expected these these are planets as big or bigger than jupiter but orbiting super close in to their
00:27:08star when the young star is forming it blows out all of the material that's very close to it the sheer
00:27:15force of the solar winds so there's nothing that could have formed right there how the heck did you
00:27:19get a planet that big that close to a star hot jupiters forced scientists to consider a radical idea
00:27:28we always assumed that planets were formed where we see them today but these hot jupiters couldn't
00:27:35have been formed there they must have migrated in from further out
00:27:40that made us look at our solar system through a different lens and all of a sudden we started
00:27:45seeing signs that oh maybe yeah maybe this happened here
00:27:49one million years after the birth of the mafia family-like solar system many small rocky planets
00:27:59grow in the inner part of the protoplanetary disk underboss jupiter makes a move to take control of the
00:28:07family the giant planet's gravity creates spiraling waves in the protoplanetary disk which drag on jupiter
00:28:17slowing it down so jupiter slows down just a little bit in its orbit around the sun and as it slows down
00:28:28it falls inwards towards the sun and migrates closer and closer jupiter crashes into the inner solar system
00:28:38in its path the infant rocky planets
00:28:41you can't take something with 300 times the mass of the earth and let it roam around the inner solar
00:28:48system and hope it's not going to do anything jupiter is like a monster truck at a stock car rally
00:28:54race right it's just plowing through everything just chaos everywhere
00:29:02so here we are forming our lovely young solar system and there are all kinds of new planets forming
00:29:07and they're settling into nice orderly orbits and here comes jupiter the big bully on the block
00:29:14enforcer jupiter pushes its smaller siblings around
00:29:19gravitationally it starts to destabilize the inner planets so nice circular orbits start to go all
00:29:25haywire and things begin to actually play pinball in the early solar system
00:29:30the growing inner planets fly off in all directions some collide violently many die in the melee
00:29:44this is a solar system demolition derby in the early days of the formation of the planets where
00:29:49things are smashing into each other and destroying little planets right and left
00:29:53this cosmic carnage could explain why we don't have any super earths
00:30:06perhaps our solar system once had large rocky planets but debris from the colliding inner planets
00:30:14slowed down their orbits dragging the young super earths into the sun
00:30:20these primordial super earths get pushed onto the sun and destroyed altogether
00:30:32it only takes a hundred thousand years to destroy the primordial group
00:30:38of super earths that it would have formed in the inner solar system
00:30:42but not everyone agrees with this version of events
00:30:45this is a pretty cool idea but i'm not convinced by it we have a lot of ideas of why we are the way
00:30:51we are today what we need is more evidence to be able to separate these ideas out
00:30:57an alternative theory suggests that jupiter stole everyone else's lunch starving the inner solar system
00:31:05of food so the planets couldn't grow into super earths
00:31:10so without jupiter earth and venus and mars might have just kept on growing and growing and growing
00:31:16we might have ended up with a bunch of super earths in the inner solar system
00:31:21mob underbossed jupiter's unprovoked assault on his smaller siblings in the inner solar system continued
00:31:28the attack caused many casualties and nearly put our planet in an early grave
00:31:35for thousands of years people have looked up at the sky and seen the planets orbiting the sun in harmony
00:31:55they've seen all of this wonderful order and that's what we thought everything formed together the sun
00:32:01the planets almost like this beautiful clockwork set up in the heavens now we know that actually that
00:32:07was far from the truth around two million years after the birth of the godfather the sun the underboss
00:32:19jupiter makes a power grab and crashes into the inner solar system
00:32:31of jupiter he continued its journey toward the sun it would have ejected a lot of the stuff that was left
00:32:38there would be no inner rocky planets it would just be jupiter
00:32:43fortunately we avoid complete slaughter something stops jupiter's murderous attack
00:32:51lucky for us we had an ace in the hole we had a friend and that friend
00:32:55is so beautiful in the sky today and we call that friend saturn
00:33:04saturn is also migrating inward toward the sun but the rate it's moving in depends on the mass
00:33:10of the planet saturn is less massive than jupiter so it's moving in more rapidly
00:33:16peacemaking conciliary saturn catches up with jupiter and brokers a deal
00:33:23when they reach each other they don't collide they get stuck in a complicated orbital dance with each
00:33:28other their cosmic tango strips out gas from the disk clearing a path for saturn and jupiter to move
00:33:36back outwards so this can actually reverse their migration and all of a sudden we have the two
00:33:42planets moving outward in the solar system so it's like saturn has a trailer hitch and is towing jupiter
00:33:48back to the outer solar system where we find them today
00:33:55saturn saved the earth basically if it hadn't been there to pull jupiter back out from the inner solar
00:34:00system jupiter would have thrown all the inner planets out so no mercury no venus no mars no earth
00:34:08three million years after the birth of the sun
00:34:11around 20 baby planets survive jupiter's ransacking of the inner solar system but the carnage isn't over
00:34:22the inner solar system's kind of in turmoil the gravitational interaction from jupiter was severe
00:34:29everything is excited orbits are out of control and crazy and things are interacting and having big
00:34:33violent collisions the inner solar system is like a congested highway
00:34:44planets cross lanes collisions are frequent
00:34:51as the bloodshed continues the young earth wanders into the path of a smaller planet
00:34:57there's a theory and it's a pretty good one that the earth a long time ago was hit by another
00:35:03relatively big planet and we called that planet theia
00:35:09theia hit earth at over 25 000 miles an hour
00:35:15the impact destroyed theia and nearly wiped out earth
00:35:19when earth was struck by theia it was unlike any event before or since we think about the event that
00:35:29wiped out the dinosaurs as a huge collision oh this one dwarfs that one
00:35:38the earth was completely turned inside out the surface was new it was molten and it was raining fire
00:35:46literally lava rock was raining down from the heavens
00:35:53earth was badly wounded but survived
00:36:00material from theia mixed with earth rock building a bigger planet and a new companion
00:36:08this collision was so huge it blasted off a tremendous amount of material off the earth's surface
00:36:13and this coalesced to form the moon
00:36:19that theory may now become fact
00:36:25we found two massive chunks of rock buried deep beneath earth's surface
00:36:30these massive lumps of rock have a different density a different composition than the rest of
00:36:36the mantle rock rock around a new study in 2021 suggests they don't come from earth
00:36:46it could be that these dense blobs of material deep in our mantle are remnants of theia
00:36:53throughout the inner solar system protoplanet hit protoplanet
00:36:57some high-speed crashes ended in catastrophe there was drama a lot of drama it's as much a story of
00:37:10destruction as it is of creation there are a lot of planets that could have made it but didn't and we
00:37:16just happen to be one of the lucky ones that did
00:37:18slower impacts glued the colliding worlds together building hybrid planets from the wreckage
00:37:31the four terrestrial planets mercury venus earth and mars emerge from the ashes of the 20 protoplanets
00:37:39and join the mob family the planets are connected you probably have some material in your body from
00:37:46pretty much every world that ever existed in the solar system everything mixed around that mixing made
00:37:53earth larger and better equipped to survive the bloodbath also left its mark on the other surviving planets
00:38:03what's strange about venus is that it actually spins in the opposite direction all the other planets
00:38:08spin sort of with with a right hand spin from the west to the east and venus spins from the east to the west
00:38:16and also venus's spin is very slow it's 243 times slower than that of earth's you can imagine a
00:38:24big protoplanetary embryo almost the size of venus itself smashing almost head on to venus
00:38:31just in the right angle to stop the rotation slow it down even actually reverse it slightly
00:38:37and now it's still spitting like that today mercury carries horrific scars from jupiter's assault on
00:38:48the inner solar system mercury has always seemed to be a bit of an odd planet because it really is
00:38:55sort of a cannonball it has a giant core compared to the rest of the planet so the question is how do
00:39:00you get this large core but very little rock very little mantle and crust around it we think mercury
00:39:08hit another planet hard the outer layers of mercury it's rocky mantle was blasted off leaving behind
00:39:18just the dense iron cannonball core of this planet which ricocheted off and then settled in mercury's
00:39:26current orbit close to the sun that leaves one last rocky planet member of the mafia family mars
00:39:43it's older and much smaller than its neighbors venus and earth
00:39:49one way to interpret mars in this scenario is that mars was one of those original 20 or 30 planetary embryos
00:39:55or proto-planets and it just survived it avoided this big violent end game of the giant impact
00:40:02stage of planet formation mars sat on the sidelines far enough away from the action to be safe from
00:40:10physical harm but enforcer jupiter's violent raid on the inner solar system still prevented mars from reaching
00:40:18its full potential one big effect of jupiter's incursion into the inner solar system is to
00:40:24blast away a bunch of material around where we find mars today in some ways jupiter kind of ate mars
00:40:30as lunch so mars just didn't have as much stuff to work with and it never became a very big planet
00:40:37after 60 million years of family feuding the battle of the planets is finally over
00:40:44out of all the mayhem and chaos of the early solar system four terrestrial planets remained one of them
00:40:50with earth given everything we've now learned about how violent it was we understand just how
00:40:56vulnerable we've been all the way along planets colliding plants even changing places in some ways
00:41:03now it's amazing the earth even survived our planet emerged as one of the winners from underboss jupiter's
00:41:10homicidal assault on the inner planets but jupiter's return to the outer solar system soon triggered more
00:41:18mayhem mayhem mayhem mayhem that would threaten earth with the biggest bombardment in its history
00:41:30the mafia family we call the solar system has survived under boss jupiter's attack on the inner planets
00:41:47but faces more disruption from its enforcer when the giant gas planet heads out towards where uranus and
00:41:54neptune grow a journey that may help explain several mysteries about the solar system including
00:42:01the size of the ice giants the biggest problem with the outer solar system is literally
00:42:08bigness uranus and neptune are too big for where they are the problem is the availability of building
00:42:15materials this far out from the sun there wasn't enough gas and dust in the protoplanetary disk to
00:42:22construct such large planets one way of solving the riddle of how uranus and neptune are so big
00:42:30is that they didn't form where they are now so we think that they formed further in and then maybe
00:42:35moved out this is what we think happened five million years after the birth of the sun jupiter and saturn
00:42:46reached the same region of space as uranus and neptune the four quarreling children call a truce
00:42:53and orbit together orbits are on the razor's edge of stability as it is and so one thing that helped
00:43:00to stabilize our solar system in the early days was that it was in this cloud of gas and dust that was
00:43:07this protoplanetary disk gas in the protoplanetary disk can slow down planets so they migrate but it
00:43:17can also stabilize their orbits like sand on the side of a racing track that's there to slow down the
00:43:25cars and help them get back on track the gas allows the planets to not veer off too much away from their
00:43:33stable compact configuration the ceasefire between the gas planets is short-lived
00:43:44once the godfather sun blows away the last of the gas the largest mafiosa children set off on another
00:43:52crime spree so when the gas goes away you no longer have this damping effect on the orbits of the giant
00:43:59planets and they can start interacting with each other and jupiter is free to be a bully again only
00:44:05this time he's got a big sidekick saturn former peacekeeper saturn joins forces with jupiter and
00:44:14they start messing with uranus and neptune so the two largest kids team up together and start pushing
00:44:22everyone else around when you put really big planets that are really massive really close to each other
00:44:27over time they start to push on each other's orbits and their orbits start to get excited
00:44:31the whole thing starts to unravel and eventually culminates in a violent and beautiful instability
00:44:42gravitational shoves from jupiter and saturn push the ice giants outwards
00:44:50uranus still bears the scars from this power move
00:44:57for one thing it's orbiting the sun on its side instead of having its rotation axis sort of straight
00:45:04up and down more or less it's tipped way over so its pole is pointing more or less toward the sun
00:45:10instead of up and down that's really weird
00:45:15recent studies suggest a giant impact caused uranus's strange orientation
00:45:21over four billion years ago a large icy object hits the ice giant with a glancing blow
00:45:32the planet starts to tip over then the attacker comes around and smashes into uranus a second time
00:45:40this one-two punch knocks the ice giant onto its side
00:45:53a clue to the cause of the collision comes from neptune's moon triton
00:46:00what's odd about triton is that it orbits the wrong way around neptune and that's the wrong way for the
00:46:05whole solar system so everything's going in this direction triton's going the other way the other
00:46:10thing is that triton is made of slightly different things than it should be at the orbit of neptune
00:46:14its color its density are just a little bit off what we think that means is that it probably
00:46:21didn't form there
00:46:25we find pointers to triton's origin on the dwarf planet pluto
00:46:30pluto sits in the kuiper belt a band of millions of icy objects beyond neptune
00:46:45when we looked at triton and compared it with pluto from telescopes from earth we we recognize
00:46:50these two are very similar to each other on triton there's nitrogen ice there's carbon monoxide
00:46:55ice there's carbon dioxide ice these are the same types of ices that we see on pluto
00:47:01this similarity in chemical composition suggests that pluto and triton formed in the same place
00:47:10an ancient band of icy objects called the trans neptunian belt
00:47:16when the giant planet orbits go berserk uranus and neptune get tossed into this trans neptunian disc
00:47:25it's like a big bowling bowl coming in and knocking off uh bowling pins left and right
00:47:35chaos ensues as the two outer planets get pushed through all of this stuff throwing things left right
00:47:41and center all kinds of collisions are inevitable one of these collisions knocks uranus over
00:47:54another small planet heads towards neptune
00:47:59the ice giant grabs it creating the moon triton
00:48:03the other trans neptunian objects scatter outwards forming the kuiper belt
00:48:16tremors from this planetary bowling match spread far and wide sparking a cataclysmic onslaught of
00:48:22the inner solar system billions of miles away the kuiper belt this very very distant collection of small
00:48:31rocky bodies in the outer solar system you would think that we have no connection to that at all
00:48:36but instead it may be responsible for helping life get started on earth
00:48:514.6 billion years ago a cloud of gas collapses in a quiet suburb of the milky way
00:48:58it's the birth of our mobster family solar system the godfather the sun ignites and takes control
00:49:09his children the planets grow from the disk of gas and dust left over from the birth of the star
00:49:18gas planets form in the cold outer suburbs rocky ones in the warm inner real estate
00:49:24but the sun's fearsome nature threatens the young earth
00:49:32the early earth right after its formation was not a great place to be alive in fact it would not have
00:49:37been possible to be alive because it was so hot it had no atmosphere it had been blown away it wasn't
00:49:44even fully solid and it had no water to speak of the earth is too close to the sun to have formed with
00:49:52the amount of water that we see today the protoplanetary disk was just too hot for water to condense
00:49:58and water vapor would have been blown away by the stellar wind
00:50:02for the same reason it was also lacking in carbon and volatile organic materials
00:50:07this raises a big mystery where did all that material ultimately come from that we now obviously
00:50:12have in abundance on planet earth
00:50:19nasa's dawn mission to the dwarf planet ceres provided a clue
00:50:26ceres sits in the asteroid belt a band of rocky debris left over from jupiter's attack on the inner
00:50:32planets the dawn mission showed us that ceres is actually a really wet world we thought it was just rock
00:50:41but instead ceres is rich in water ammonia and carbon
00:50:50these chemicals are essential for life
00:50:55analysis of other asteroids found lots of this volatile material
00:51:01this is surprising because this close in the sun should have vaporized them
00:51:07they could not have formed in the asteroid belt because temperatures were way too high
00:51:13for those materials water ammonia to be able to condense they must have formed in the outer solar system
00:51:19and then been transported to the inner solar system
00:51:24a 2019 study discovered evidence of a storm of icy objects raining inwards around 4.48 billion years ago
00:51:35the same time the giant gas planets were tearing through the outer solar system
00:51:42as jupiter and saturn uranus and neptune are migrating back outwards in the solar system
00:51:48they're excavating a whole slew of icy planetesimals like a like a snow plow
00:51:53bursting through a snow drift scattering these things all through the solar system
00:51:56the outer planets hurl millions of icy objects in towards their dawn the sun
00:52:10some like ceres stop in the asteroid belt
00:52:15others continue and smash into the inner planets
00:52:19including earth
00:52:26we are being rained down on by giant asteroids comets the entire surface of the earth is
00:52:32molten again i mean it is a rain of the largest objects you can imagine onto the surface of the
00:52:38earth everything just would have been completely smashed to pieces imagine something like the dinosaur
00:52:45killing impact happening once a month the onslaught lasts for 30 million years
00:52:55it pulverizes the earth's surface
00:53:00but brings fresh chemicals to replace material blasted away by the sun
00:53:06all of these asteroids and comets raining down on earth of course are causing massive amounts of
00:53:11destruction but they're bringing the building blocks of life as well the carbon-based molecules that
00:53:16make us up the water that every bit of life on earth needs all of the conditions necessary for life
00:53:22were brought by that bombardment if that chaotic bombardment hadn't happened it's just possible that
00:53:30we wouldn't be here today even though some of our mob family now live in the outer reaches of the solar
00:53:36system the family ties to the planets in the inner regions are still strong the distances between
00:53:44all of the planets in our solar system are large you get a sense of that if you go into
00:53:49the night sky and jupiter and saturn are pinpricks of light but really they're all interconnected in a
00:53:54very complex way gravity is this huge effect and and can go over long distances
00:54:00the solar system has this huge violent past as these giants have moved and interacted it's really
00:54:10remarkable how interconnected all these planetary bodies really are even though we think of them as
00:54:15very separate this interaction between planets billions of miles apart transformed the inner solar
00:54:26system and primed earth for life but our planet was still uninhabitable the early earth right after
00:54:37the bombardment would have been a complete hellscape it would have been really hot magma everywhere big
00:54:44impact craters with impact melts all across the floors it would have been unrecognizable not only was
00:54:52it incredibly hot but it also didn't have an atmosphere and at that time there was no liquid
00:54:57water on the surface yet early earth could not have supported life for life to start earth must cool down
00:55:06and build a new atmosphere the earth developed its second atmosphere using materials delivered
00:55:13by the great bombardment all of these volatiles like water and carbon organic materials were incorporated
00:55:20into the earth's crust and then volcanoes were able to outgas all of these materials forming a very thick
00:55:26layer of gas this new atmosphere had a composition that was mostly water vapor carbon dioxide and nitrogen
00:55:34over the next 30 million years earth cools a solid surface forms
00:55:42as the planet is cooling the water vapor in the atmosphere is going to be
00:55:46raining out that's going to form pools of liquid water on the surface of the earth
00:55:54the earliest evidence for liquid water on earth was 4.3 billion years ago remember that's just
00:55:59200 million years after its formation which is really fast
00:56:04trillions of gallons of water rain down torrential rains for i mean you know imagine monsoon rains for
00:56:13you know tens and tens of thousands of years all this water would have rained onto the surface rained rained
00:56:22and eventually filled up our oceans
00:56:28the oceans pull life-forming chemicals from the rocks and the atmosphere creating the primordial soup
00:56:35life can begin we used to be so disconnected from each other each planet just living entirely separately
00:56:45now we know things mix around now we know that probably the building blocks of life itself and
00:56:50the water in my body actually came from the outer solar system i like that
00:56:55a series of interconnecting and often violent incidents going right back to the start of the solar system
00:57:04led to our existence if you look at what the solar system has been through
00:57:10what has to happen for life to happen when you add all of those things up we shouldn't exist we just
00:57:16shouldn't be here the chances are so so slim and yet here we are the earth has managed to survive a lot
00:57:24of the nonsense the solar system has thrown at it and some of that is probably just luck of the draw
00:57:30so i think even on our worst days we should remember that we're pretty lucky just to be here
00:57:36earth won the cosmic game of chance but were the other mafiosa children as lucky did mars and venus
00:57:45also develop environments capable of supporting life
00:58:00200 million years after the birth of the sun the mafia family prospers
00:58:07the inner planets have the building blocks of life thrown in from the outer solar system
00:58:16so in theory they could be habitable
00:58:24but when the russian probe venera landed on venus in 1970 it found a scorching hostile world
00:58:33the conditions on venus are crazy the temperature on the surface is over 800 degrees fahrenheit this is
00:58:39hot enough to melt lead the first probes that landed on venus functioned for a little while and then they
00:58:45were crushed like a tin can and melted it has a huge crushing atmospheric pressure which is 90 times
00:58:54that on the earth's surface and that's entirely carbon dioxide
00:59:01and it gets worse still because gases in the atmosphere have combined to make really this
00:59:06concentrated solution of acids so you've got this noxious acidic corrosive environment coupled with
00:59:14very very high temperatures life as we know it could not survive on the surface of venus as it is today
00:59:26new climate models suggest that four billion years ago venus was a very different planet to the one we see
00:59:33today these models suggest that in the past venus had actually a cooler surface temperature and had a
00:59:41better composition for habitability
00:59:46we think it once had a much thinner atmosphere much more like earth's atmosphere today it would have had
00:59:52a climate which was much much cooler and therefore even the possibility of liquid water on the surface
01:00:01maybe venus had oceans in the way that we find on earth still today it even makes sense that venus would
01:00:09be similar to earth because it formed out of basically the same materials close to the same location from the sun
01:00:15and ended up being even almost the same size really we are twin planets
01:00:24the barrage of icy objects from the outer solar system that struck earth also hit venus
01:00:32just like earth venus got a whole bunch of volatiles from bombardments and those in turn were recycled
01:00:39and produced a very nice atmosphere and allowed water to exist on the surface as a liquid
01:00:47these early conditions on venus could have provided a habitat the right sort of conditions for life to
01:00:56have got started what about mars was it also habitable looking at it today all we see is a frozen
01:01:05barren wasteland part of the reason it's so cold is it's further away from the sun and it doesn't
01:01:11have a very thick atmosphere so it's very hard for it to retain heat it also has extremely low atmospheric
01:01:18pressure which means that any liquid water on the surface would just boil away and any current water
01:01:24that's on the planet is locked up in ice however recent surveys of mars reveal a very different planet
01:01:33once capable of supporting life as you look across the landscape of mars you can see these physical
01:01:40features that give us hints that water used to exist there like dried lake beds and river beds
01:01:47we see abundant evidence of river channels drainages all across the landscape the best way i think the
01:01:54only way to form these is by rainfall there had to have been clouds and rain in mars's past and there's
01:02:00also sediments and mineral deposits that could only form in the presence of liquid water
01:02:09we calculate that mars once had five million cubic miles of liquid water on the surface
01:02:16that's enough for an ocean bigger than the earth's arctic ocean so we think that mars
01:02:22had an ocean in its northern hemisphere to have oceans mars must have had a thick atmosphere
01:02:34and recently a space probe orbiting the red planet found evidence
01:02:42the maven mission revealed that mars is losing its atmosphere rapidly i mean this is something like a
01:02:48quarter pound a second of atmosphere being stripped away by the solar wind we can take those maven loss
01:02:54rates for mars's atmosphere and extrapolate back in time and we can see that mars had an atmosphere as
01:03:00thick as earth's in the past with a thicker atmosphere mars would have been able to retain heat much more
01:03:06effectively and would have had increased atmospheric pressure which would have allowed liquid water to
01:03:11persist on the surface in the past mars would have been just a beautiful landscape filled with running rivers and lakes
01:03:19and that water could have potentially sustained ancient life
01:03:25all of the observations that we have of mars to date just tell us that it was absolutely a habitable world
01:03:34so now we have an earth that had kind of settled down after the heavy bombardment of venus that might have
01:03:39water on the surface water on the surface water on the surface water on all three surfaces maybe all
01:03:47three were ripe for life it's actually remarkable to think that all three of these planets could have been
01:03:53habitable at the same time but this golden age of habitability is short-lived
01:04:00another battle erupts between the planets and their dawn the sun venus and mars suffer serious collateral damage
01:04:21four billion years ago the mob family the solar system is thriving
01:04:33the children earth mars and venus have the conditions to sustain life
01:04:382020 scientists investigate how mars became uninhabitable
01:04:52they detect faint magnetic traces coming from lava spewed out by ancient volcanic eruptions
01:04:59the magnetic lava on mars tells us that when that lava was molten there was a strong global magnetic field on that planet
01:05:16dating the rocks tells us that mars's magnetic field was active 4.5 billion years ago
01:05:23having a magnetic field really helps a planet retain its atmosphere and that's just because a magnetic field
01:05:31protects the planet's atmosphere from incoming radiation solar wind cosmic rays you name it
01:05:44on earth liquid iron churning around the hot molten core generates a magnetic field
01:05:53the younger mars would have still had a much hotter core with churning convection currents in its interior
01:06:01and these would have generated a global magnetic field in exactly the same way the earth creates its magnetic field
01:06:11mars couldn't maintain its magnetic field
01:06:16because jupiter's violent assault on the inner solar system stole the red planet's lunch
01:06:21jupiter migrated in about where mars is today so that means that most of the material was actually
01:06:29swallowed up by the gravity of jupiter so mars just got unlucky small planets lose heat faster tiny mars
01:06:38cooled down and so as mars's core cooled the convection in that core would have slowed down to the point where no
01:06:46magnetic field would be generated once the magnetic field at mars is shut off well that's the end of the
01:06:52protection for the atmosphere
01:06:563.7 billion years ago the sun attacks the defenseless mars
01:07:04the solar wind just bombards it and strips it away the atmosphere very quickly over time
01:07:09without its thermal blanket mars's surface freezes and the atmospheric pressure plummets
01:07:20as the atmospheric pressure drops surface water gradually evaporates or even boils away
01:07:26the air to the air to the air to the air to the air to the air to the air to the air
01:07:33Venus also suffered a climate catastrophe
01:07:38we find clues on its surface
01:07:44like all planetary sized bodies in the solar system
01:07:47Venus has impact craters on it from asteroids smacking into it but there aren't that many which is a
01:07:53little lot they're not damaged like the craters we see on other worlds they look pristine as if
01:08:02nothing has modified them as if they happened yesterday so that suggests these craters and the
01:08:07surface on which they reside are both very young there are several theories suggesting that volcanic eruptions
01:08:15resurfaced the planet around 500 million years ago
01:08:18one idea is that venus has a very thick crust and it doesn't move around in plates like earth's does
01:08:27so it's just a lid over the planet and eventually the pressure builds up and builds up and builds up until
01:08:32it boom lets out all at once
01:08:40a catastrophic event that overturned the entire crust of venus and resurfaced it
01:08:49an alternate theory suggests the resurfacing happened over millions of years
01:08:55a series of large volcanic eruptions that would have completely resurfaced the planet
01:09:03imagine watching this event on venus i mean the overturn of an entire crust
01:09:09that's just completely awe-inspiring
01:09:12volcanic events release huge amounts of gas
01:09:19icelandic volcano eafrat ajakitol blasts out up to 300 000 tons of carbon dioxide every day
01:09:29venus's planet-wide volcanism would have been off the charts
01:09:36such a huge worldwide bout of volcanic activity would release huge amounts of carbon dioxide into the venusian
01:09:45atmosphere
01:09:48scientists think this enormous release of gas may have triggered the venusian climate change
01:09:55carbon dioxide built up in venus's atmosphere trapping heat from the sun
01:10:02as soon as the climate on venus started to warm up a little there's greater evaporation coming off the
01:10:08oceans and that water vapor in the atmosphere is itself a greenhouse gas the climate gets even warmer
01:10:19venus reaches 880 degrees fahrenheit
01:10:22any chance for life broils away
01:10:34the earth also faces a searing hot future when the aging godfather the sun bloats up and attacks his family
01:10:43once again transforming into a lethal weapon of mass destruction
01:10:49for the last four billion years our mob family the solar system lived in harmony
01:11:08but nothing lasts forever the godfather the sun will grow old fat and mean
01:11:19stars like the sun only have enough hydrogen to fuse for about 10 billion years
01:11:25so that means that in about 5 billion years the sun will actually run out of hydrogen
01:11:30with no hydrogen fuel left fusion stops the core collapses and reignites fusing helium
01:11:51the energy released by all of this fusion causes the star to balloon outwards and become a red giant
01:12:03the red giant is like a bitter old gangster bloated and aggressive it attacks the inner planets
01:12:15mercury and venus are going to be engulfed by the sun as it becomes a red giant
01:12:18the sun as it becomes a red giant it burns up both planets next in line earth
01:12:27then the universe throws us a lifeline
01:12:32as the sun expands outward as it enters its red giant phase it's actually going to be losing mass
01:12:42the red giant blows off gas
01:12:44and as it loses mass its gravity is weakening so this means that the sun's grip on the planets that
01:12:53orbit it is going to be weakening and so they sort of start moving away from the sun it's almost like
01:12:59they're running away from the heat if you can't stand the heat get out of the solar system
01:13:06can earth and mars outrun the expanding red giant
01:13:09so it's a race right who is going to get far enough from the sun to escape being engulfed by it
01:13:19the eventual fate of the earth is not clear
01:13:23it's possible that the earth will be completely swallowed up by the sun's atmosphere its new bloated
01:13:30red atmosphere even if the earth escapes being directly engulfed by the sun it's still not a good
01:13:43day for our planet because the sun is going to be really really close so imagine basically something
01:13:50red hot glowing covering the sky the earth will be molten in fact a lot of it will vaporize
01:13:56so it's not like you're going to want to be here anyway as i look at this scenario what's clear is
01:14:02that life isn't going to make it on earth
01:14:09mars had a head start and escapes complete destruction
01:14:14it'll be cooked i mean it'll be a molten planet but it'll still be there
01:14:18the aging dawn wipes out life in the inner solar system
01:14:28but may help it survive elsewhere
01:14:32the sun's red giant phase may initially bring new opportunities for life in the outer solar system
01:14:39right now the outer solar system is locked in ice it's way too cold but when our sun becomes a red giant
01:14:46it will become much much brighter it will warm up the outer system
01:14:54and transform the gas giants icy moons
01:15:00europa and enceladus that orbit jupiter and saturn respectively are currently frozen worlds
01:15:05they have icy crusts and are believed to have liquid oceans below those crusts
01:15:16so they're not going to be in the outer space
01:15:18scientists believe that these subsurface oceans may harbor life
01:15:25as the temperature increases their frozen exteriors are going to be
01:15:28thawed and they'll become entirely ocean worlds
01:15:36any life forms already evolving in their oceans will have a whole new world of possibility open to them
01:15:41or if life isn't there yet then it would certainly have a chance to evolve
01:15:47we may have explosions of life on these other outer solar system bodies
01:15:54but this burst of new life may be short-lived
01:15:59even though these ocean worlds may seem like a great place to move to after the
01:16:03inner solar system is engulfed i would not start packing yet
01:16:13the red giant will grow to over 250 times its current size
01:16:19as the sun continues to expand these new ocean worlds will start getting hotter and hotter and
01:16:25eventually all of the water will evaporate away
01:16:32any new life dies out
01:16:37but bodies in the furthest reaches of the solar system fare better
01:16:43the key to surviving the sun turning into a red giant is basically distance
01:16:48so the farther out you are from the sun now the better off you are then
01:16:51the best bet might be the distant dwarf planets like pluto
01:17:02so now we have these objects that might actually become the most earth-like bodies in the solar
01:17:07system these may be our lifeboats
01:17:15i mean they won't have breathable atmospheres and it's not like they're going to be great places to
01:17:18live but you know the earth is going to be basically toast at that point so you know what choice do you have
01:17:24humanity may use the warm outer bodies as stepping stones to a new home because when the godfather's son
01:17:32gets very old he becomes frail and unable to stop other more powerful dons from destroying the solar system
01:17:41forever
01:17:56six billion years in the future
01:18:00the aging godfather's attack on his children ends
01:18:04the bloated red giant dies releasing a burst of energy which blasts the outer regions of the star
01:18:14plus the remains of the vaporized planets out into space
01:18:21ready to build new stars and new planets
01:18:25what's left are veils of beautiful colored gas called a planetary nebula the surviving planets
01:18:36and at the heart the remains of the sun
01:18:42now nothing but a burnt out core
01:18:47we call those leftover cores from small stars white dwarf stars and they're much smaller than the sun
01:18:54the white dwarf will be about half the sun's original mass and all contained into the size of the earth
01:19:03the dense white dwarf doesn't burn fuel so it can't generate energy
01:19:10the solar system cools we'll start seeing freezing from the outer solar system to the inner solar system
01:19:17we'll start with pluto
01:19:21then enceladus around saturn and then europa around jupiter and then finally mars
01:19:29so you know they've already had any volatiles sent away their surfaces are now going to be metallic
01:19:35and rocky and you're going to end up with these very frozen rocky metallic worlds
01:19:40the near-dead godfather is now a shadow of his former self and the solar system is at the mercy of
01:19:51more powerful mobster stars the white dwarf of the sun has about half the mass of the sun today
01:19:58which means gravity is half as strong so the planets in their orbits will move further out
01:20:03these outer planets which survived the sun turning into a red giant their orbits are now much much
01:20:11larger than they were before up to about a factor of two that's an issue because there are other stars
01:20:18in the galaxy we're part of the milky way galaxy and our best estimate is that there's something like
01:20:24a hundred billion other suns like ours orbiting our galaxy every 20 million years something like that
01:20:33one of them will pass by close enough to affect the orbits of these planets
01:20:41so in this distant future where our sun is a white dwarf as our orbits are larger and things are
01:20:47moving slower we're way more susceptible to the effects of passing stars
01:20:50you can imagine this like ships passing each other in the ocean where as one whizzes by another it
01:20:59creates waves that knock the other one around passing stars will give the planets little nudges little
01:21:08kicks the giant planets will enter a chaotic phase where everything except for jupiter will be scattered
01:21:16out of the solar system 50 billion years in the future the solar system faces another ruthless gangster
01:21:27out on the make its gravity is going to yank jupiter away from the sun and fling it out into
01:21:33interstellar space and jupiter will become a rogue planet all that's left of our once strong mafia family
01:21:41the sun eight planets and countless moons is the small weak white dwarf eventually a white dwarf cools
01:21:51so much that it no longer emits radiation and it becomes what we call a black dwarf
01:21:59and this is basically just a burnt out shell of a star composed of oxygen and carbon
01:22:05it can form a carbon crystal which we happen to call diamonds so think of a black dwarf as a diamond in the sky
01:22:18a cosmic gem destined to wander the galaxy for eternity
01:22:23our solar system formed from chaos but grew from collaboration between the planets and the sun
01:22:37we know the planets affect us we know the sun affects us in a few billion years the sun's really
01:22:41going to affect us the more we look at this stuff the more we realize that everything affects everything
01:22:47else including us without all of these things into playing the earth wouldn't have the stable
01:22:55environment that we have today and life wouldn't be able to exist and so the chances are small but it's
01:23:00worked out well for us as we piece together the events that have i think shaped our solar system
01:23:09you step back and think about all the moving parts all of the chance encounters all of the chaos
01:23:14and it's hard not to think that we're really lucky to be sitting here on this planet earth
01:23:21in the future our mafia family will be gone but somewhere out in the milky way a new mobster star
01:23:30system may rise from the ashes of our own one of the trends that we see in our universe is that
01:23:37destruction leads to creation the fact that our star is going to one day die doesn't mean that it's the
01:23:44the end of anything it's the beginning