0:00:01.600,0:00:02.834
sᴜᴘᴘᴏʀᴛ ʙʏ
0:00:02.834,0:00:04.350
sᴜᴘᴘᴏʀᴛ ʙʏ[br]Protocol Labs
0:00:04.350,0:00:05.419
sᴜᴘᴘᴏʀᴛ ʙʏ[br]Protocol Labs[br]Follow your curiosity.
0:00:05.419,0:00:09.187
sᴜᴘᴘᴏʀᴛ ʙʏ[br]Protocol Labs[br]Follow your curiosity.[br]Lead humanity forward.
0:00:09.187,0:00:09.437
Protocol Labs[br]Follow your curiosity.[br]Lead humanity forward.
0:00:09.437,0:00:09.687
Follow your curiosity.[br]Lead humanity forward.
0:00:16.820,0:00:19.129
"In all the universe,
0:00:19.129,0:00:24.540
"In all the universe,[br]there stands only one known tree of life."
0:00:31.421,0:00:34.443
"Does it stand alone?
0:00:34.443,0:00:40.311
"Does it stand alone?[br]Or is it part of a vast cosmic wilderness?"
0:00:46.038,0:00:52.517
"Imagine a museum[br]containing every type of life in the universe."
0:00:58.362,0:01:00.757
"What strange things would such a museum hold?"
0:01:16.257,0:01:18.667
"What is possible under the laws of nature?"
0:01:39.767,0:01:40.906
LIFE
0:01:40.906,0:01:45.610
LIFE BEYOND
0:01:49.016,0:01:49.885
CHAPTER II
0:01:49.885,0:01:55.406
CHAPTER II[br]The Museum Of Alien Life
0:02:02.805,0:02:03.657
To have any hope-
0:02:03.657,0:02:05.506
of finding alien life,
0:02:05.537,0:02:07.408
we have to know what to look for.
0:02:12.060,0:02:13.945
But where do we begin?
0:02:15.303,0:02:16.446
How do we narrow down...
0:02:16.568,0:02:18.068
a seemingly infinite set-
0:02:18.068,0:02:20.175
of possibilities...
0:02:27.310,0:02:29.968
There's one thing we know for sure...
0:02:30.683,0:02:32.045
nature will have to play-
0:02:32.075,0:02:33.375
by her own rules.
0:02:36.791,0:02:38.166
No matter how strange-
0:02:38.196,0:02:39.806
alien life might be,
0:02:40.386,0:02:41.180
is going to be limited-
0:02:41.220,0:02:42.596
by the same physical...
0:02:42.606,0:02:44.756
and chemical laws that we are....
0:02:46.952,0:02:47.014
6
0:02:47.014,0:02:47.077
6 C
0:02:47.077,0:02:47.139
6 CO
0:02:47.139,0:02:47.202
6 CO₂
0:02:47.202,0:02:47.264
6 CO₂ +
0:02:47.264,0:02:47.327
6 CO₂ + 6
0:02:47.327,0:02:47.389
6 CO₂ + 6 H
0:02:47.389,0:02:47.452
6 CO₂ + 6 H₂
0:02:47.452,0:02:47.514
6 CO₂ + 6 H₂O
0:02:47.514,0:02:47.577
6 CO₂ + 6 H₂O +
0:02:47.577,0:02:47.639
6 CO₂ + 6 H₂O + L
0:02:47.639,0:02:47.702
6 CO₂ + 6 H₂O + Li
0:02:47.702,0:02:47.764
6 CO₂ + 6 H₂O + Lig
0:02:47.764,0:02:47.827
6 CO₂ + 6 H₂O + Ligh
0:02:47.827,0:02:47.889
6 CO₂ + 6 H₂O + Light
0:02:47.889,0:02:47.952
6 CO₂ + 6 H₂O + Light →
0:02:47.952,0:02:48.014
6 CO₂ + 6 H₂O + Light → C
0:02:48.014,0:02:48.077
6 CO₂ + 6 H₂O + Light → C₆
0:02:48.077,0:02:48.139
6 CO₂ + 6 H₂O + Light → C₆H
0:02:48.139,0:02:48.202
6 CO₂ + 6 H₂O + Light → C₆H₁
0:02:48.202,0:02:48.264
6 CO₂ + 6 H₂O + Light → C₆H₁₂
0:02:48.264,0:02:48.326
6 CO₂ + 6 H₂O + Light → C₆H₁₂O
0:02:48.326,0:02:48.389
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆
0:02:48.389,0:02:48.451
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ +
0:02:48.451,0:02:48.514
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6
0:02:48.514,0:02:48.576
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O
0:02:48.576,0:02:51.613
6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O₂
0:02:51.613,0:02:52.312
On top of this,[br]6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O₂
0:02:52.312,0:02:52.733
On top of this,
0:02:53.244,0:02:53.694
each alien environment will further limit-
0:02:53.694,0:02:55.239
each alien environment will further limit-[br]ʜʏᴅʀᴏɢᴇɴ
0:02:55.239,0:02:55.672
each alien environment will further limit-[br]ᴏxʏɢᴇɴ
0:02:55.672,0:02:57.374
what kinds of life forms can evolve there.[br]ᴏxʏɢᴇɴ
0:02:57.374,0:02:59.376
what kinds of life forms can evolve there.[br]ɴɪᴛʀᴏɢᴇɴ
0:03:06.992,0:03:09.189
Despite these natural boundaries,
0:03:09.243,0:03:12.206
the possibilities are staggering to imagine.
0:03:14.235,0:03:15.640
Trillions of planets,
0:03:15.778,0:03:17.878
each a unique cauldron of chemicals,
0:03:17.924,0:03:23.076
undergoing their own complex evolution.
0:03:28.150,0:03:29.360
To guide our thinking,
0:03:29.598,0:03:31.316
this museum of alien life-
0:03:31.316,0:03:34.396
will be divided into two exhibits...
0:03:35.668,0:03:36.929
Life as we know it,
0:03:37.194,0:03:38.295
home to beings-
0:03:38.295,0:03:40.950
with bio-chemistries like ours.
0:03:41.694,0:03:43.588
And life as we don't know it,
0:03:44.068,0:03:45.038
home to beings-
0:03:45.038,0:03:47.828
that challenge our concept of life itself.
0:03:54.022,0:03:54.986
Before we venture-
0:03:55.042,0:03:56.889
too far into the unknown,
0:03:57.103,0:03:59.177
we have to ask ourselves...
0:03:59.956,0:04:01.089
what if alien life-
0:04:01.183,0:04:02.253
is more like us...
0:04:02.253,0:04:03.939
than we think?
0:04:10.759,0:04:12.728
EXHIBIT I
0:04:12.728,0:04:14.746
EXHIBIT I[br]Life As We Know It
0:04:14.746,0:04:15.174
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ
0:04:15.174,0:04:16.307
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ[br]If there's one feature-
0:04:16.307,0:04:17.327
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ[br]that unites us...
0:04:17.327,0:04:19.510
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ[br]with these other specimes in this museum,
0:04:19.510,0:04:19.922
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ
0:04:19.922,0:04:21.245
EXHIBIT I[br]Life As We Know It[br]ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ[br]it's carbon...
0:04:21.775,0:04:24.670
Carbon
0:04:24.670,0:04:26.377
Carbon[br]Carbon is ubiquitous,
0:04:26.437,0:04:27.514
Carbon[br]it's one o' tho most-
0:04:27.514,0:04:29.450
Carbon[br]common elements in the universe,
0:04:29.515,0:04:30.923
Carbon[br]and is very good at forming-
0:04:30.923,0:04:33.505
Carbon[br]large stable molecules.
0:04:33.505,0:04:37.183
Carbon
0:04:37.183,0:04:41.563
Carbon[br]Carbon has the rare ability to form four way[br]bounds with other elements
0:04:41.563,0:04:41.807
Carbon
0:04:41.807,0:04:44.564
Carbon[br]and to bind to itself in [br]long, stable chains;
0:04:46.424,0:04:49.624
enabling the formation of [br]huge complex molecules.
0:04:56.197,0:04:59.093
This versatility makes carbon the center piece
0:04:59.093,0:05:01.130
in the moleculary machinery of life.
0:05:03.520,0:05:07.742
And the same carbon compounds that we use[br]have been found far from Earth,
0:05:08.736,0:05:10.087
clinging to meteorites
0:05:12.359,0:05:15.623
and floating in far off [br]clouds of cosmic dust.
0:05:18.670,0:05:23.518
The building blocks of life drifting [br]like snow through the universe.
0:05:30.162,0:05:34.920
And if alien life has selected other carbon[br]compounds for the biochemistry,
0:05:35.783,0:05:37.413
they will have plenty to choose from.
0:05:42.088,0:05:47.570
Scientists recently identified over a [br]million possible alternatives to DNA:
0:05:48.588,0:05:49.862
all carbon based.
0:05:57.948,0:06:00.795
If we ever discover other [br]carbon based life forms,
0:06:01.650,0:06:03.973
we will be fundamentally related.
0:06:07.928,0:06:09.840
They will be our cosmic brother.
0:06:13.296,0:06:15.137
But would they look anything like us?
0:06:19.975,0:06:21.742
If they hail from Earth like planets,
0:06:22.857,0:06:24.471
we could share even more in common,
0:06:25.065,0:06:26.417
than just our biochemistry.
0:06:29.826,0:06:33.104
What would life be like in another[br]planets, if its evolved?
0:06:33.566,0:06:36.246
Would it be like, the world [br]today here on Earth?
0:06:37.477,0:06:38.736
Or would be completely different?
0:06:38.819,0:06:42.121
There are those, who argue that
0:06:42.456,0:06:44.470
from the argument of convergent evolution,
0:06:44.803,0:06:50.206
if conditions on other planets are similar to here, then we will see very similar life forms;
0:06:54.726,0:06:58.236
animal and plant-like organisms, that look very familiar.
0:07:12.238,0:07:16.618
On Earth, certain features like eyesight, echo-location and flight
0:07:16.628,0:07:20.812
have evolved multiple times, independently, in different species.
0:07:23.648,0:07:28.978
This process of convergent evolution could extend to alien planets like Earth,
0:07:29.222,0:07:32.242
where creatures share similar environmental pressures.
0:07:35.632,0:07:40.372
It's no guarantee, but there could be certain universalities of life;
0:07:44.337,0:07:48.337
the greatest hits of evolution on repeat across the Universe.
0:07:58.040,0:08:02.040
Each feature would be a tune to its local environment.
0:08:02.798,0:08:09.491
Dimly lit planets would produce huge eyes to suck in extra light, like nocturnal mammals.
0:08:14.190,0:08:19.231
Some people have gone so far as to say [br]that human type organism, humanoids,
0:08:19.231,0:08:20.809
will occur on other planets.
0:08:26.136,0:08:29.706
The existence of other human-like[br]organisms seems unlikely,
0:08:30.155,0:08:33.602
given the long convoluted chain[br]of events that produced us.
0:08:35.296,0:08:36.400
But we can't rule it out.
0:08:40.817,0:08:44.838
If just one in every 100 trillion[br]Earth-like planets produced
0:08:44.838,0:08:49.551
a human-like form, the could still be[br]thousands of creatures like us out there.
0:09:02.605,0:09:07.335
But in reality, we are more likely to find[br]something lower on the food chain.
0:09:10.171,0:09:13.423
Convergent evolution is also [br]rampant in plant life
0:09:14.037,0:09:19.312
and C4 photosynthesis has arisen [br]independently over 40 times.
0:09:21.799,0:09:25.178
Would alien plants look like ours or[br]something else entirely?
0:09:36.926,0:09:40.857
On Earth, plants appear green because[br]they absorb the other wavelenghts
0:09:40.997,0:09:42.537
in the Sun's light spectrum.
0:09:45.739,0:09:47.778
But stars come in many colors
0:09:52.629,0:09:56.984
and alien plants would evolve different pigments [br]to adapt to their sun's unique spectrum.
0:10:04.431,0:10:07.530
Plants feeding off hotter stars[br]could appear redder,
0:10:08.284,0:10:11.161
by absorbing their energy rich bluer light.
0:10:19.761,0:10:24.219
Around dim Red Dwarfs stars, [br]vegetation could appear black,
0:10:25.072,0:10:28.155
adapted to absorb all visible[br]wavelengths of light.
0:10:45.058,0:10:47.572
Earth itself may have once [br]appeared purple,
0:10:48.101,0:10:52.004
due a pigment called retinal, that was [br]an early precursor to chlorophyll.
0:10:55.019,0:10:57.779
Some think that retinal's molecular simplicity
0:10:58.189,0:11:00.547
could make it a more universal pigment.
0:11:04.070,0:11:09.146
If so, we may find that purple,[br]is life's favorite color.
0:11:19.820,0:11:23.713
But the color of alien vegetation[br]is more than just a curiosity,
0:11:25.696,0:11:29.155
it's chemical information that could[br]be seen from light years away.
0:11:34.504,0:11:38.528
Earth plants leave a signature bump [br]in the light reflected off our planet.
0:11:40.306,0:11:43.434
Finding a similar signal from another [br]world could point the way
0:11:43.647,0:11:45.116
to alien vegetation.
0:11:50.376,0:11:53.866
Perhaps this will be our first glimpse at alien life;
0:11:54.965,0:11:58.375
a vibrant hue, cast by a distinct world.
0:12:12.005,0:12:20.055
But the biggest influence on life won't be it's host star; it will be it's home planet.
0:12:20.715,0:12:23.415
What happens, when you change the day - length of a planet?
0:12:23.495,0:12:25.465
What happens when you change the tilt of a planet?
0:12:25.545,0:12:27.626
What happens when you change the shape of the orbit?
0:12:27.965,0:12:30.637
What happens when you change the gravity of a planet?
0:12:34.498,0:12:38.938
Planets with long, elliptical orbits would see drastic seasons.
0:12:41.298,0:12:44.823
There could be worlds that appear dead for thousands of years,
0:12:45.528,0:12:47.496
then suddenly spring to life.
0:13:02.583,0:13:07.073
Most of the rocky planets discovered so far have been massive "Super Earths".
0:13:09.243,0:13:12.433
GJ 357 DSuper Earth Distance : ~ 31 Light Years Mass : ~ 7× Earth Temperature : ~ -53°C
0:13:12.570,0:13:15.097
How would life evolve on these worlds?
0:13:18.580,0:13:21.656
In the seas, gravity may not matter much at all.
0:13:29.590,0:13:32.120
A high - gravity planet isn't high - gravity all over.
0:13:33.680,0:13:37.660
If you're in the sea, that's where all life starts, there's very nearly no gravity,
0:13:37.660,0:13:40.225
cause you're much the density as the stuff around you.
0:13:43.450,0:13:47.270
It's when the animals come out on land, that they feel the gravity.
0:13:51.628,0:13:53.628
High G - forces [vaguely, gravitational forces] would necessitate
0:13:53.628,0:13:57.458
large bones and muscle mass in complex life on land.
0:13:59.748,0:14:03.178
They would also demand a more robust circulatory system.
0:14:04.958,0:14:10.578
And plant life could be stunted by the energy cost of carrying nutrients under stronger gravity.
0:14:17.318,0:14:21.446
Low - gravity planets would more easily lose their atmospheres to space;
0:14:21.838,0:14:25.158
and lack a magnetic field to protect from cosmic rays.
0:14:35.821,0:14:39.091
But smaller worlds could be home to secret oases;
0:14:46.251,0:14:49.451
huge cave systems that provide hide-outs for life.
0:15:02.751,0:15:11.242
With steadier temperatures and protection from cosmic rays, life could thrive underground on planets with deadly surfaces.
0:15:26.732,0:15:33.093
The smallest possible habitable planets are estimated at 2.5% Earth's mass.
0:15:35.042,0:15:37.735
If surface life does evolve on these worlds,
0:15:38.822,0:15:40.766
it could be a sight to behold.
0:15:44.584,0:15:47.064
Plant life could grow to towering heights,
0:15:47.484,0:15:50.594
able to carry nutrients higher, at lesser gravity.
0:15:59.194,0:16:02.611
And without the need for bulky skeletons and muscle mass,
0:16:02.904,0:16:06.031
animals could have body types, that boggle the mind.
0:16:22.292,0:16:28.347
Despite our eager imagination, large complex lifeforms are probably a cosmic rarity.
0:16:31.631,0:16:34.920
Here on Earth, it took three[br]billion years for evolution
0:16:34.920,0:16:37.234
to produce complex plant and animal life.
0:16:39.723,0:16:42.584
Simple organisms are hardier, [br]more adaptable
0:16:42.986,0:16:44.041
and more widespread.
0:16:48.383,0:16:51.390
The largest collection in the[br]museum of alien life
0:16:51.390,0:16:54.309
would likely be the Hall of Microbes.
0:17:10.306,0:17:14.674
Yet finding even the tiniest alien microbe[br]would be a profound discovery.
0:17:30.735,0:17:33.619
And bite-sized life could leave[br]a big footprint.
0:17:35.892,0:17:39.997
Like stromatolites on Earth, layers of[br]microbes could build up into huge
0:17:39.997,0:17:41.170
rock mounds over time.
0:17:41.642,0:17:43.876
Leaving behind eery structures.
0:17:48.780,0:17:51.202
And in big enough numbers [br]some alien
0:17:51.202,0:17:54.004
bacteria could leave a [br]distinct biosignature,
0:17:55.964,0:17:58.622
by exhaling gases that wouldn't [br]coexist naturally:
0:17:59.453,0:18:01.124
like oxygen and methane.
0:18:07.406,0:18:08.996
There's ways to make oxygen without life.
0:18:08.996,0:18:10.579
There's ways to make methane without life.
0:18:11.067,0:18:12.582
But to have them in the atmosphere together?
0:18:13.212,0:18:16.501
Is almost impossible unless you've got [br]biology making those gases at the surface.
0:18:17.883,0:18:20.828
And it would have a imprint on[br]the planet's spectrum of colors.
0:18:22.945,0:18:26.267
Next generation space telescopes[br]could find a signal like this,
0:18:28.574,0:18:30.531
on a world not far from home.
0:18:32.274,0:18:36.578
The closest Sun-like star with an[br]Earth-like exoplanet in the
0:18:36.578,0:18:40.206
habitable zone is probably only[br]20 light years away
0:18:40.489,0:18:42.409
and can be seen with a naked eye.
0:18:46.298,0:18:52.373
But there may be an even easier target to aim for than tiny Earth-like planets.
0:18:54.805,0:19:02.008
The Brown Dwarfs: too small to [br]be stars, to big to be planets.
0:19:06.389,0:19:09.928
Most Brown Dwarfs are too hot[br]to support life as we know it.
0:19:11.136,0:19:12.604
But some are just cold enough.
0:19:13.978,0:19:14.558
WISE 0855-0714
0:19:14.758,0:19:15.008
WISE 0855-0714[br]Sub-Brown Dwarf
0:19:15.008,0:19:15.258
WISE 0855-0714[br]Sub-Brown Dwarf[br]Distance: 7 Light Years
0:19:15.268,0:19:15.518
WISE 0855-0714[br]Sub-Brown Dwarf[br]Distance: 7 Light Years[br]Mass: 3.10x Jupiter
0:19:15.518,0:19:22.724
WISE 0855-0714[br]Sub-Brown Dwarf[br]Distance: 7 Light Years[br]Mass: 3.10x Jupiter[br]Temperature: -50 - -13ºC
0:19:24.457,0:19:28.640
All the prime elements for life have[br]been detected inside their atmospheres.
0:19:31.588,0:19:35.755
And within these clouds, some layers[br]would provide ideal temperatures
0:19:35.755,0:19:37.456
and pressures for habitability.
0:19:46.176,0:19:48.938
There could be photosynthetic [br]plankton in these skies,
0:19:50.092,0:19:52.500
kept aloft by churning upwinds.
0:19:57.603,0:20:01.186
And with enough force, these upwinds[br]could even support larger,
0:20:01.186,0:20:02.722
more complex life.
0:20:06.101,0:20:06.754
Predadors.
0:20:15.348,0:20:19.238
There are over 25 billion Brown [br]Dwarfs in our galaxy alone,
0:20:19.238,0:20:24.396
and their sizes will make them [br]easier targets for study.
0:20:27.046,0:20:35.235
The first specimen we discover from the museum of life may not be from a planet at all.
0:20:44.142,0:20:46.054
This raises a crucial question:
0:20:47.920,0:20:50.253
what if we've been looking in[br]all the wrong places?
0:20:52.618,0:20:54.896
What if nature has other ideas?
0:20:58.925,0:21:01.213
EXHIBIT II
0:21:01.213,0:21:03.494
EXHIBIT II[br]LIFE AS WE DON'T KNOW IT
0:21:03.494,0:21:08.057
EXHIBIT II[br]LIFE AS WE DON'T KNOW IT[br]EXOTIC BIOCHEMISTRIES
0:21:21.172,0:21:25.627
Most of the Universe is too cold or too[br]hot for liquid water and the
0:21:25.627,0:21:28.161
biochemistry that supports [br]life as we know it.
0:21:31.514,0:21:33.544
But in case our biases are misleading,
0:21:34.680,0:21:36.307
we have to cast a wide net.
0:21:38.908,0:21:41.431
To search for life outside [br]the habitable zone,
0:21:42.271,0:21:44.881
in places that seem wildly hostile to us.
0:21:49.586,0:21:53.085
Exotic environments will demand[br]exotic biochemistries.
0:21:53.646,0:21:56.533
And while no element can match [br]carbon's versatility,
0:21:57.125,0:21:58.918
one contender is a front runner.
0:22:07.707,0:22:10.713
At first glance, silicon seem [br]similar to carbon.
0:22:13.025,0:22:16.850
It forms the same four-way bonds and is[br]also abundant in the Universe.
0:22:19.462,0:22:23.215
But a closer look reveals that these [br]two elements are false twins.
0:22:27.388,0:22:32.397
Silicon bonds are weaker and less prone[br]to forming large complex molecules.
0:22:36.420,0:22:39.961
Despite this, they can withstand [br]a wider range of temperatures,
0:22:41.050,0:22:43.670
opening up intriguing possibilities.
0:22:47.381,0:22:50.405
Life based on the silicon atom [br]instead of carbon,
0:22:50.698,0:22:53.262
would be more resistant to [br]the extreme cold.
0:22:54.722,0:22:57.982
Providing a whole new range of weird forms.
0:23:01.491,0:23:02.755
But silicon has a problem:
0:23:04.616,0:23:08.125
in the presence of oxygen, [br]it binds into solid rock.
0:23:10.373,0:23:13.339
To avoid turning to stone, silicon beings
0:23:13.339,0:23:15.970
might be confined to oxygen free environments.
0:23:16.598,0:23:18.717
Like Saturn's frigid moon, Titan.
0:23:18.717,0:23:23.048
TITAN[br]Saturnian Moon[br]Distance: 1,2 Million KM[br]Mass: .023X Earth[br]Temperature: -129ºC
0:23:23.048,0:23:27.089
Its vast lakes of liquid methane and[br]ethane could be an ideal medium
0:23:27.089,0:23:28.755
for silicon-based life,
0:23:29.204,0:23:31.472
or other radical biochemistries.
0:23:37.433,0:23:39.913
Without ample sunlight, beings on worlds
0:23:39.913,0:23:42.961
like Titan, would likely be chemosynthetic.
0:23:43.337,0:23:46.043
Deriving their energy by[br]breaking down rocks.
0:24:01.536,0:24:03.770
Such life forms could have ultra slow
0:24:03.770,0:24:07.906
metabolisms and life cycles [br]measured in millions of years.
0:24:16.015,0:24:21.377
And frozen worlds aren't the only possible[br]harbor for exotic life.
0:24:22.566,0:24:23.026
CoRoT-7B
0:24:23.026,0:24:23.376
CoRoT-7B[br]Super Earth
0:24:23.376,0:24:23.626
CoRoT-7B[br]Super Earth[br]Distance: ~520 Light Years
0:24:23.636,0:24:23.886
CoRoT-7B[br]Super Earth[br]Distance: ~520 Light Years[br]Mass: -8x Earth
0:24:23.886,0:24:25.961
CoRoT-7B[br]Super Earth[br]Distance: ~520 Light Years[br]Mass: -8x Earth[br]Temperature: 1026-1526ºC
0:24:25.961,0:24:30.279
In high temperatures, typically rigid[br]silicon oxygen bonds become more
0:24:30.279,0:24:31.780
flexible and reactive.
0:24:33.003,0:24:34.831
Triggering more dynamic chemistry.
0:24:40.080,0:24:42.846
This has led to a truly bizarre proposal:
0:24:43.704,0:24:48.609
silicon-based life forms that live[br]inside molten silicate rock.
0:25:01.093,0:25:03.424
In theory, these forms could even exist
0:25:03.424,0:25:06.104
deep beneath the Earth inside [br]magma chambers
0:25:06.306,0:25:08.460
as part of a shadow biosphere.
0:25:12.472,0:25:16.505
If so, then the aliens are right[br]under our noses.
0:25:20.799,0:25:23.017
Other shadow biospheres have [br]been proposed:
0:25:23.570,0:25:27.036
forms of life living alongside us[br]that we don't even know are here.
0:25:27.528,0:25:30.416
Including tiny RNA-based life, small
0:25:30.416,0:25:33.543
enough to go undetected by [br]existing instruments.
0:25:46.821,0:25:50.797
Clouds of dust and empty space might [br]seem like the last place you'd expect
0:25:50.797,0:25:52.092
to find anything living.
0:25:54.398,0:25:57.207
But when cosmic dust makes[br]contact with plasma,
0:25:57.570,0:25:59.006
a type of ionized gas,
0:25:59.494,0:26:00.717
something strange happens.
0:26:05.770,0:26:08.338
In simulated conditions, dust particles,
0:26:08.341,0:26:11.105
have been seen spontaneously [br]self-organizing
0:26:11.105,0:26:13.623
into helical structures that resemble DNA.
0:26:18.848,0:26:22.262
These plasma crystals even begin[br]to exhibit life-like behavior:
0:26:23.728,0:26:28.464
replicating, evolving into more stable[br]forms and passing on information.
0:26:35.715,0:26:38.878
Could these crystals be considered alive?
0:26:41.564,0:26:48.715
To some researchers, they meet all the criteria[br]to qualify as inorganic life forms.
0:26:52.469,0:26:57.113
So far, we have only ever seen them in computer simulations.
0:26:58.443,0:27:04.672
But some speculate we could find them[br]among the ice particles in the rings of Uranus.
0:27:12.270,0:27:15.761
Plasma is the most common state [br]of matter in the Universe.
0:27:17.666,0:27:20.769
If complex evolving plasma [br]crystals really exist
0:27:21.252,0:27:22.758
and if they can be considered life,
0:27:23.377,0:27:25.253
they could be its most common form.
0:27:38.505,0:27:43.043
Or perhaps life is lurking in the [br]polar opposite environment:
0:27:43.043,0:27:46.997
inside the hearts of dead stars.
0:27:51.400,0:27:54.319
When massive suns explode, some collapase into
0:27:54.319,0:27:57.044
ultra dense cores called neutron stars.
0:27:57.044,0:27:58.168
PSR B1509-58[br]Neutron Star[br]Distante: 17,000 Light Years[br]Spin Rate: ~7/second
0:27:58.168,0:28:01.902
Hulking masses of atomic nuclei [br]crammed together like sardines.
0:28:05.556,0:28:07.774
Conditions on the surface are mind-boggling:
0:28:08.922,0:28:12.210
gravity is a hundred billion times [br]stronger than Earth's.
0:28:15.724,0:28:19.243
But beneath their iron nuclei [br]crust lies something strange:
0:28:21.474,0:28:25.358
a hot dense sea of neutrons[br]and subatomic particles.
0:28:34.550,0:28:36.827
Stripped of their electron shells, these
0:28:36.827,0:28:39.906
nuclei would obey entirely [br]different laws of chemistry,
0:28:40.486,0:28:42.714
based not on the electromagnetic force,
0:28:42.994,0:28:44.956
but the strong nuclear force,
0:28:45.227,0:28:46.655
which binds nuclei together.
0:28:49.720,0:28:52.129
In theory, these particles could link-up
0:28:52.129,0:28:55.406
to form larger macronuclei, [br]which could then
0:28:55.406,0:28:58.253
combine into even bigger super nuclei.
0:29:06.696,0:29:09.665
If so, then this bewildering environment
0:29:09.665,0:29:11.714
would mimic the basic conditions for life.
0:29:12.484,0:29:16.745
Heavy nucleon molecules floating [br]in a complex particle ocean.
0:29:22.729,0:29:25.221
Some scientists have proposed [br]the unimaginable:
0:29:26.532,0:29:30.326
exotic life forms drifting through [br]the strange particle sea,
0:29:31.143,0:29:35.880
living, evolving and dying on [br]incomprehensibly fast time scales.
0:29:55.942,0:30:01.025
There's probably no chance of ever detecting[br]such a strange breed of life.
0:30:02.572,0:30:07.802
But there may be hope for finding [br]an even more exotic form.
9:59:59.000,9:59:59.000