How Did The Earth Form?

perched on the surface of a survivor we survey the solar system 16 million years have passed since solid matter first froze in the solar nebula only 1.3 percent of Earth's history those first tiny particles of matter coalescing initially into dust then mountain sized planetesimals and finally dozens of planetary embryos doomed for a fight to the death now after an explosive race for mass and dominance only a handful of proto planets remain the surface of our proto planet is a blasted and blazing wasteland coated by dead oceans of magma fueled by the primal Inferno of atomic decay sustained for a time by the bruising reign of planetesimals but these are mostly gone now too absorbed by hungry worlds or else ejected into the depths of the solar system and picked off by the leviathans lurking there the table scraps of this primal feast fall regularly on to our proto planet one of its most successful feeders on the surface of fractured heaps of fused and jagged debris blasted apart by the incessant bombardment a hazy atmosphere of carbon dioxide blankets the broken landscape moisture wets the dust somewhere on the surface they may even be a new kind of ocean forming we may even imagine that someday this scrappy champion will sprout another newcomer life or we would be wrong our proto planet is not earth its name is Thea despite an impressive start Thea is not destined to win this planetary competition for another combatant lurks in its orbit over the horizon another proto planet Corrine's interview Thayer's a larger cousin the earth having experienced its own similar and short history this young world is just moments away from its final act of formation the burning sphere swells until it is eaten the sky at last with a deafening Rumble the two survivors crush into one another towering waves of material erupt and cascade into roiling chaos chunks of planet splash into orbit as the earth devours its last meal the ruptured planet consumes Thea hole as the energy of the impact melt solid rock into oceans of liquid magma yet again in the sky the blazing chaos gradually quiets and the process of accretion begins this disk of debris will soon form the Earth's eternal companion the moon this is Thea's gravestone [Music] you [Music] [Music] after nearby supernova sent shockwaves through our featureless cloud of gas and dust after that cloud began to collapse spinning ever faster as it shrank spreading outwards as its spun after the Sun kindled into being at the center of that shrinking spinning spreading cloud the first two fragments of dust at the center of our story crash into each other and stick together welcome to earth our world begins as a scattering of dust particles so small gravity cannot even hold them together static electricity instead sticking each piece to another the disc around the Sun is transforming from gas into dust the clouds freezing into silicate crystals and complexes of calcium and aluminium magnesium and iron as they grow they experience drag for the first time the gas they were once part of now sapping their energy the largest of these nebula snowflakes cascade from the outskirts collecting at the disks central plane as our nascent earth drifts towards the Sun it is also falling in on itself the more the snowflakes grow the more energy is sapped by the passing nebula earth faces its most dangerous challenge if it does not grow quickly it will be captured by the gravity of the Sun and plummet into the furnace worse as our clump of dust expands to the size of a pebble the electrostatic forces feeding it cease to be effective yet neither can gravity bring new material to an object so small pebbles drift past each other unaffected a fortunate few collide only to ricochet and drift apart or worse fragment and disperse growth has stalled [Music] [Music] in the inner disk vast throngs of meteors stream towards the Sun many are as large as a metre across and still struggling to grow most will not survive but the earth is truly lucky it is located in a region of concentrated nebula that will collapse mutually attracted by its cumulative mass the earth expands rapidly past the danger zone now it can set its own traps for its doomed cousins siphoning off mass bound for the Sun while the meteors plunge inward the gas billows away radiation from the juveniles Sun pushes the vapors outward the hydrogen and helium leave the earth behind carbon leaves water leaves even potassium and sulfur leave carried away by solar winds the earth will not see these elements again for millions of years as the earth grows into a planetesimal many kilometers in diameter it begins to melt the closest material has always been scorched by the Sun but this heat doesn't originate from the heart of the nebula but from the matter of the nebula itself radioactive decay the raw fire of nuclei tortured into unstable monstrosities now concentrated on the proto-earth they are self-immolating on mass aluminium 26 a demon born alongside the nebula has a half-life of only seven hundred and thirty thousand years the energy of its destruction melts the interior of the earth separating the heavy metallic iron from the lighter elements it sinks to the center of the planetesimals gloms together for the first time Earth has a core but the earth is not alone while a tremendous volume of material is plunged into the Sun a multitude of other planetesimals Corrine through its neighborhood and more are forming all the time these bodies now commence a battle for survival and for a place in the solar system mostly molten mountains of material roamed the disk for their prey these gladiators destroy and a lesser body drawn in by their gravitational pull when two equally matched combatants cross paths a fling each other wildly into new orbits at first chaos rules over the arena with such spoils readily available the largest planetesimals grow exponentially but once the frontrunners of this battle royale have established themselves a tense truce settles in each combatant carves out a zone of influence an uncontested orbit where it can systematically finish off every other opponent the earth emerges is one of these champions settling down to a comfy snack but in this solar system there is always a bigger fish Jupiter advances from the outer regions formed by the frozen volatiles once ejected from the inner disk the primordial jupiter edges ever closer planetesimals ensnared by the behemoth share two fates they are devoured by this icy tighten or fatally flung from the solar system into oblivion and with each doomed body launched outwards jupiter lurches inwards within reach of more victims jupiter rampages through a hapless crowd of fleeing and flying planetesimals ever closer to the unformed vulnerable earth at just one-and-a-half times the distance from the earth to the Sun Jupiter's attention is snatched by another colossal beast Saturn locked in gravitational combat these two monsters heave and shove each other dragging themselves ultimately back into the depths of the outer disk left behind is a depopulated wasteland the only planet that will form in this vast region is the comparatively tiny Mars staffed of material Mars is mostly complete after the first few million years safe in the inner disk the future planets of Mercury and Venus are forming as his earth perched on the edge of no-man's land the luckiest survivor only a couple of million years have passed since the creation of the solar nebula and much has changed the gas has drifted away the nuclear Inferno has calmed Jupiter has come and gone already most of the mass in the inner disk is concentrated in dozens of planetary embryos one to ten percent of the mass of the modern earth among them are the adolescent Mercury Venus Mars Earth and Theia as well as many other contenders it will take many tens of millions more years to decide the ultimate winners [Music] while Jupiter lays waste to the edge of the inner disk the Sun wreaks havoc near its center 50 kilometres from the Sun her children whip around at incredible speeds collisions here are catastrophic when proto planets clash it is rarely clean instead they rip into each other spraying their insides across the void and part again circling then clash again on the next orbit and the next finally the two bodies will collapse into each other when proto mercury encounters another embryo they impact with such ferocity their Mantle's vaporize Jets of gaseous planets spout away from the roiling course leaving mercury much reduced in mass and enriched in iron with so many gladiators and such erratic sparring the ultimate Victor's will be chosen by chance as this happens glimpses of future earth appear the firestorm of radioactivity has died away but the oceans of magma it created still burble beneath the surface as the oceans slowly solidify the materials of the earth organized themselves iron sinks to the core along with nickel and other heavy elements that bond with iron crystals precipitate in the swirling molten matter most shower onto the core and amass Indians thousands of kilometers thick the lightest elements and the most unreactive seep upwards and outwards and freeze near the surface the earth forms layers asteroids explode through the whisper thin atmosphere and blast the solid surface into dust it accumulates into drifts until the direct impact fuses the matter into solid stone once again great vents breached the surface and molten mantle leaks through seas of magma puddle and solidified but this cohesion is short-lived Armageddon returns to earth each time it devours a defeated foe surface is vaporized Mantle's sloshed and a new surface congeals earth starts again water and the other volatiles reappear after tens of millions of years absent asteroids planetesimals possibly even ice rains down upon our proto planet now with something to cling to the carbon ice and gases that were driven away by the heat of the Sun have begun to repopulate the Earth's surface after 16 million years of halting growth and abortive evolution the earth has nearly reached its final mass only one more collision one more victim separates Earth from the end of its origin story and the beginning of its history there's orbit intersects that of Earth [Music] by their combined gravity they turn towards each other and lean into the below the impact is devastating crushed between the two planets solid rock atomizes shockwaves liquefy the mantle fragments of the earth buried thousands of kilometers deep are ejected into space the planet staggers on its axis as it crumples back into a sphere oceans of Hellfire tumble onto the surface superheated gas and droplets of magma suffocate the earth the extremities of this lunar disk rapidly coalesce into a hellish sphere the dwarfs even the Sun [Music] over the next 150 years the cloud of dust billows outward little moonlets coagulate and spin off to join the moon it is a replica of the Earth's formation we played in miniature this is the last altercation Earth has with another proto planet asteroid and planetesimals continued falling to earth and the moon for hundreds of millions more years but another impact of this magnitude would have left scars on the moon if not obliterated entirely Thayer's destruction is unique only in that it came last many other upstarts met similar fates at the hands of the earth it's probable that several different moons graced the sky around our planet before our moon formed it is a sign of the changing times that this companion sticks around the earth is done growing but it is far from complete our planet is not a blue marble but red and black and broken after 60 million years Earth has only begun its journey a journey that will change it from the edge of the atmosphere to it's very core [Music] [Music]

Channel: History of the Earth

Views: 586,422

Keywords: Formation, genesis, start of earth, space, solar system, jupiter, accretion, billions, nasa, science, history, earth, world, Mars, deep space, asteroid

Id: 0_a_xU2KQdE

Length: 18min 15sec (1095 seconds)

Published: Sat May 09 2020