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We think of life as confined to a single

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planet.

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But the nature of life

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is to spread,

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to seek out new horizons,

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to take root on foreign shores

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in search of new soils.

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to make its mark on the cosmos.

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Heat.

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Heat.

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If you were to travel back in time 4.4

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billion years ago, you might not have

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picked Earth as the future cradle of

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life.

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But Mars,

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smaller and quicker to cool, Mars formed

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a solid crust and flowing water. long

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before the Earth,

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giving it a 100 millionyear head start

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to spark life.

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Clues from Martian meteorites and rovers

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tell the story of a once vibrant world

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with rivers winding across ancient

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valleys,

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lakes pooling in craters

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and a vast open ocean spanning the

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northern hemisphere.

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In Jezero crater in ancient river delta,

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NASA's Perseverance rover found a

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curious mudstone rock named Shyava

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Falls.

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Formed when liquid water covered the

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planet billions of years ago,

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it contains strange pale leopard spots,

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each rich in minerals and organic

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molecules that on Earth often point to

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microbial activity.

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So far, researchers have no natural

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explanation for these patterns, meaning

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that these spots could be the fossils of

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ancient Martian microbes.

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And our first true glimpse at alien

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life.

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But if there really was life here long

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ago, it would have been under attack,

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pummeled by a 300 millionyear asteroid

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storm

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on the surface. These impacts would have

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been apocalyptic for life.

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But underground, they may have been a

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gift.

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Residual heat from large impacts may

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have created thousands of underground

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mineralrich water systems that stayed

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heated for millions of years.

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Ideal incubators for life, protected

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from the chaos on the surface.

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But the barrage of impacts had another

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effect.

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Rocks blasted into space by the impacts

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spread throughout the solar system

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with billions of tons of Martian

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material making contact with Earth.

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13,000 years ago, one of these rocks

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struck the Allen Hills in Antarctica.

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It was found to have originated in a

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deep Martian canyon at a time when Mars

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still had flowing water.

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And deep inside we found these

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strange structures that look like

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fossilized bacteria.

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It now appears they are just natural

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mineral formations. But these structures

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stirred a deep question.

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What if it wasn't just Martian rocks

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coming to Earth,

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but Martian life?

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What if our oldest ancestors came from

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Mars

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or further beyond?

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This is the theory of panspermia.

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And for it to work, life has to survive

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the gauntlet.

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A three-stage journey from hell.

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First stage, survive being launched into

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space several times faster than a

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speeding bullet.

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Inside a superheated fragment of rock

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with surface temperatures exceeding

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1,000° C.

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Second stage. Endure the long journey

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through the frozen vacuum of space

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devoid of water, air, or nutrients for

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potentially millions of years.

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All while being bombarded by ultraviolet

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radiation that can shred DNA to pieces.

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Final stage. Withstand the fiery

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re-entry to a new world as your frozen

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lifeboat becomes a fireball.

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life uh finds a way.

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Spores of the bacterium basillus

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subtillus have been recovered alive just

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millimeters inside a rock as its outer

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surface was superheated to over 400° C.

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Tardigrades one of the smallest and

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heartiest animals known have been

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witnessed surviving the freezing vacuum

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of space for at least 10 days without

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protection.

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They do this with a unique protein

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called DUP

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which forms a protective cloud around

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their DNA.

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But when it comes to battling radiation,

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the undisputed king is the bacterium

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denocus radios.

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It can withstand radiation levels a

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thousand times higher than a dose fatal

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to humans.

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Its superpower is its ability to

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reassemble its own shattered DNA,

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rebuilding its entire genome in a matter

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of hours.

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Heat. Heat.

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Dead microbial remains contain fragments

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of DNA that carry valuable information.

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These fragments could have spilled out

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into Earth's primordial soup, providing

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readymade materials to jumpstart life.

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This is the theory of necropanspermia.

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Like mana from heaven, the essential

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molecules of life could have rained down

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on our planet

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from some ancient branch of life.

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If true,

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Earth life could be written with

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borrowed words from a story that began

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far from our shores,

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delivered here by microbial martyrs.

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But perhaps it was the other way around.

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Perhaps Earth was the cradle for life

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and a launch pad for its journey to

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other worlds.

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Tens of millions of rock fragments from

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Earth have made it to Mars.

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But due to its closer orbit, Venus may

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have received far more,

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potentially 100 times more over the

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eons.

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Together, these three planets formed a

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bustling meteoric trade network, sharing

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billions of fragments over billions of

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years.

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Some rocks travel as far as Jupiter and

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its moons,

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potentially seeding their underground

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oceans.

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Even Saturn is thought to have received

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possibly millions of Earth fragments,

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some splashing down into the liquid

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methane lakes of Titan.

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Seen in this way, the solar system could

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be a constellation of life

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intermixing its biochemistry through an

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interplanetary asteroid highway.

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But this might only be scratching the

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surface.

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In fact, life could be connected not

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just between planets,

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but between entire star systems.

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The average distance between neighboring

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stars in our cosmic neighborhood is

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about four light years, around 40

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trillion km.

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This journey would take millions of

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times longer, making survival even less

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probable,

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but not impossible.

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Studies show that microbes shielded

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inside 3 ft of rock could survive the

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cosmic radiation of deep space for tens

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of millions of years.

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Comets could make the perfect

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interstellar arcs as their thick mantles

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of water ice form a natural radiation

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shield for any microbial passengers.

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But the best way to close the gap is to

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pack the stars closer together.

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Most stars in the universe are born

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within dense clusters

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packed in tight with other suns.

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In these crowded cosmic neighborhoods,

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the distance between stars isn't

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measured in light years,

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but in light months or light weeks.

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Our

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own son was no exception.

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Born inside a crowded stellar nursery

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with neighbors far closer than they are

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today.

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During this period lasting up to 90

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million years, our solar system and its

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nearest neighbor could have swapped up

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to 30 quadrillion solid objects.

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As many as 200 billion rocks from the

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young lifebearing Earth could have

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reached alien star systems.

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If we ever touch down on nearby alien

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worlds,

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we might just find that they are part of

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our family tree.

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And some star systems could be even more

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interconnected.

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Globular clusters, the dense swarms of

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stars that orbit our galaxy, contain

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thousands or millions of suns packed

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into a tight ball.

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For any planets inside these clusters,

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the night sky would be permanently

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ablaze with thousands of nearby stars,

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some shining as brightly as full moons.

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At these stellar densities, an asteroid

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carrying microbial life wouldn't need

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millions of years to reach the next star

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system,

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but perhaps only thousands.

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Across our galaxy, trillions and

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trillions of rogue planets wander the

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darkness alone, cast out of their home

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system,

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their surfaces frozen to near absolute

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zero.

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But deep inside, some could retain a

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molten core which could supply heat to a

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subsurface ocean.

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A perfect sanctuary for an interstellar

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journey

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down here. Hidden biospheres could sail

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safely through the void for millions or

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even billions of years using the planet

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itself as a starship.

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A lucky few could even make the epic

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journey to an entirely new galaxy.

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potentially making panspermia an

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intergalactic phenomenon.

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But what if life didn't need to ride a

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planet or rock at all?

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By constructing a living shell to keep

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in heat and block radiation, communities

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00:20:45,520 --> 00:20:51,120
of cells could weave their own wandering

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00:20:48,240 --> 00:20:53,280
habitats,

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00:20:51,120 --> 00:20:55,600
self- sustaining bubbles of life that

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float through space like miniature

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living planets.

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Inside they'd hold liquid water, recycle

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nutrients, and use distant sunlight for

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energy.

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All without ever landing on a planet.

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By optimizing their size to a few meters

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wide, they'd be strong enough to hold

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pressure, yet light enough to drift

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00:21:31,520 --> 00:21:36,520
through space like cosmic plankton.

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Imagine

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a creature so large that it rivals the

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size of entire planets.

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It glides gracefully through the void,

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guided by an internal organ that senses

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the faint gravitational pull of distant

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suns.

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Despite its completely alien nature,

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this titanic creature voyages the

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darkness for a familiar reason.

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to raise its young.

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Using entire worlds as incubators

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Heat up here.

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Heat.

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Heat.

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Heat.

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Heat.

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00:24:51,600 --> 00:24:56,799
Like cosmic gardeners, advanced

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civilizations could be casting seeds of

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life across the universe, possibly as

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backup copies of their species. She

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00:25:26,080 --> 00:25:31,679
could treat the galaxy like a vast

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garden bed, spreading seeds and watching

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how they take root on different worlds.

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And we could even discover that our own

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tree of life is just a branch of another

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civilization's ancient grand experiment.

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Heat.

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Heat.

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Heat.

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Heat.

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Heat. Heat.

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Heat up

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here.

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Heat

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up

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here.