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Supported by
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Supported by
Protocol Labs
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Supported by
Protocol Labs
Follow your curiosity.
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Supported By
Protocol Labs
Follow your curiosity.
Lead humanity forward.
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Protocol Labs
Follow your curiosity.
Lead humanity forward.
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Follow your curiosity.
Lead humanity forward.
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"In all the universe,
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"In all the universe,
there stands only one known tree of life."
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"Does it stand alone?
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"Does it stand alone?
Or is it part of a vast cosmic wilderness?"
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"Imagine a museum
containing every type of life in the universe."
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"What strange things would such a museum hold?"
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"What is possible under the laws of nature?"
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LIFE
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LIFE BEYOND
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CHAPTER II
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CHAPTER II
The Museum Of Alien Life
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To have any hope-
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of finding alien life,
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we have to know what to look for.
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But where do we begin?
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How do we narrow down...
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a seemingly infinite set-
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of possibilities...
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There's one thing we know for sure...
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nature will have to play-
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by her own rules.
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No matter how strange
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alien life might be,
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is going to be limited-
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by the same physical...
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and chemical laws that we are....
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6
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6 C
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6 CO
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6 CO²
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6 CO² +
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6 CO² + 6
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6 CO² + 6 H
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6 CO² + 6 H²
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6 CO² + 6 H²O
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6 CO² + 6 H²O +
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6 CO² + 6 H²O + L
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6 CO² + 6 H²O + Li
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6 CO² + 6 H²O + Lig
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6 CO² + 6 H²O + Ligh
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6 CO² + 6 H²O + Light
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6 CO² + 6 H²O + Light →
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6 CO² + 6 H²O + Light → C
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6 CO² + 6 H²O + Light → C⁶
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6 CO² + 6 H²O + Light → C⁶H
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6 CO² + 6 H²O + Light → C⁶H¹
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6 CO² + 6 H²O + Light → C⁶H¹²
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6 CO² + 6 H²O + Light → C⁶H¹²O
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6 CO² + 6 H²O + Light → C⁶H¹²O⁶
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6 CO² + 6 H²O + Light → C⁶H¹²O⁶ +
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6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6
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6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O
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6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O²
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On top of this,
6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O²
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On top of this,
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each alien environment will further limit-
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each alien environment will further limit-
-Hydrogen-
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each alien environment will further limit-
-Oxygen-
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what kinds of life forms can evolve there.
-Oxygen-
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what kinds of life forms can evolve there.
-Nitrogen-
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Despite these natural boundaries,
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the possibilities are staggering to imagine.
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Trillions of planets,
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each a unique cauldron of chemicals,
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undergoing their own complex evolution.
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To guide our thinking,
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this museum of alien life-
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will be divided into two exhibits...
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Life as we know it,
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home to beings-
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with bio-chemistries like ours.
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And life as we don't know it: home to beings
that challenge our concept of life itself.
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Before we venture too far
into the unknown,
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we have to ask ourselves:
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what if alien life is more
like ours than we think?
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EXHIBIT I
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EXHIBIT I
LIFE AS WE KNOW IT
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EXHIBIT I
LIFE AS WE KNOW IT
CARBON & WATER BASED
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If there's one feature that unites us with
these other specimes in this museum, it's carbon.
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Carbon is ubiquitous, it's one of the
most common elements in the universe,
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and is very good at forming
large stable molecules.
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Carbon has the rare ability to form four way
bounds with other elements
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and to bind to itself in
long, stable chains;
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enabling the formation of
huge complex molecules.
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This versatility makes carbon the center piece
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in the moleculary machinery of life.
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And the same carbon compounds that we use
have been found far from Earth,
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clinging to meteorites
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and floating in far off
clouds of cosmic dust.
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The building blocks of life drifting
like snow through the universe.
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And if alien life has selected other carbon
compounds for the biochemistry,
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they will have plenty to choose from.
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Scientists recently identified over a
million possible alternatives to DNA:
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all carbon based.
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If we ever discover other
carbon based life forms,
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we will be fundamentally related.
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They will be our cosmic brother.
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But would they look anything like us?
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If they hail from Earth like planets,
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we could share even more in common,
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than just our biochemistry.
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What would life be like in another
planets, if its evolved?
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Would it be like, the world
today here on Earth?
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Or would be completely different?
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There are those, who argue that
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from the argument of convergent evolution,
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if conditions on other planets are similar to here, then we will see very similar life forms;
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animal and plant-like organisms, that look very familiar.
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On Earth, certain features like eyesight, echo-location and flight
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have evolved multiple times, independently, in different species.
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This process of convergent evolution could extend to alien planets like Earth,
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where creatures share similar environmental pressures.
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It's no guarantee, but there could be certain universalities of life;
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the greatest hits of evolution on repeat across the Universe.
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Each feature would be a tune to its local environment.
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Dimly lit planets would produce huge eyes to suck in extra light, like nocturnal mammals.
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Some people have gone so far as to say
that human type organism, humanoids,
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will occur on other planets.
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The existence of other human-like
organisms seems unlikely,
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given the long convoluted chain
of events that produced us.
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But we can't rule it out.
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If just one in every 100 trillion
Earth-like planets produced
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a human-like form, the could still be
thousands of creatures like us out there.
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But in reality, we are more likely to find
something lower on the food chain.
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Convergent evolution is also
rampant in plant life
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and C4 photosynthesis has arisen
independently over 40 times.
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Would alien plants look like ours or
something else entirely?
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On Earth, plants appear green because
they absorb the other wavelenghts
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in the Sun's light spectrum.
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But stars come in many colors
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and alien plants would evolve different pigments
to adapt to their sun's unique spectrum.
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Plants feeding off hotter stars
could appear redder,
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by absorbing their energy rich bluer light.
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Around dim Red Dwarfs stars,
vegetation could appear black,
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adapted to absorb all visible
wavelengths of light.
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Earth itself may have once
appeared purple,
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due a pigment called retinal, that was
an early precursor to chlorophyll.
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Some think that retinal's molecular simplicity
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could make it a more universal pigment.
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If so, we may find that purple,
is life's favorite color.
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But the color of alien vegetation
is more than just a curiosity,
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it's chemical information that could
be seen from light years away.
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Earth plants leave a signature bump
in the light reflected off our planet.
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Finding a similar signal from another
world could point the way
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to alien vegetation.
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Perhaps this will be our first glimpse at alien life;
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a vibrant hue, cast by a distinct world.
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But the biggest influence on life won't be it's host star; it will be it's home planet.
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What happens, when you change the day - length of a planet?
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What happens when you change the tilt of a planet?
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What happens when you change the shape of the orbit?
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What happens when you change the gravity of a planet?
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Planets with long, elliptical orbits would see drastic seasons.
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There could be worlds that appear dead for thousands of years,
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then suddenly spring to life.
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Most of the rocky planets discovered so far have been massive "Super Earths".
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GJ 357 DSuper Earth Distance : ~ 31 Light Years Mass : ~ 7× Earth Temperature : ~ -53°C
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How would life evolve on these worlds?
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In the seas, gravity may not matter much at all.
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A high - gravity planet isn't high - gravity all over.
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If you're in the sea, that's where all life starts, there's very nearly no gravity,
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cause you're much the density as the stuff around you.
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It's when the animals come out on land, that they feel the gravity.
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High G - forces [vaguely, gravitational forces] would necessitate
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large bones and muscle mass in complex life on land.
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They would also demand a more robust circulatory system.
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And plant life could be stunted by the energy cost of carrying nutrients under stronger gravity.
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Low - gravity planets would more easily lose their atmospheres to space;
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and lack a magnetic field to protect from cosmic rays.
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But smaller worlds could be home to secret oases;
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huge cave systems that provide hide-outs for life.
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With steadier temperatures and protection from cosmic rays, life could thrive underground on planets with deadly surfaces.
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The smallest possible habitable planets are estimated at 2.5% Earth's mass.
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If surface life does evolve on these worlds,
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it could be a sight to behold.
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Plant life could grow to towering heights,
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able to carry nutrients higher, at lesser gravity.
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And without the need for bulky skeletons and muscle mass,
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animals could have body types, that boggle the mud.