This is a collaboration video with RealLifeLore.
Be sure to follow the link at the end of this video to check out his work!
This is Earth.
Every human being that's ever lived has called it home.
A seemingly lone bastion of life in an otherwise barren universe.
Earth is something very special.
Despite our best efforts, we've never detected any form of life beyond our pale blue dot.
Why is that?
What attributes make planet earth a better host for life than any other celestial body?
First and foremost, the presence of liquid water
Based on our current understanding, liquid water is a pre-requisite for life as we know it.
Thanks to a number of crucial factors not present on a number of other planets, Earth is perfectly suited for water.
The primary factor we are going to consider is the
Earth's location relative to the Sun.
Our little blue planet resides in what's
called the habitable zone which is the
range of orbits around a star within
which a planet could support liquid
water, given sufficient atmospheric
pressure. This limited band is often
aptly referred to as the "Goldilocks
zone". Any closer to the star and the
planet is too hot.
Any further and it's too cold. Luckily
for us the planet Earth sits comfortably
within the habitable zone of our sun.
Because of this prime galactic real
estate, earth has played host to a
dazzling array of life forms, from single
cells all the way to incredibly complex
beings. You might be thinking, with all the
billions of other planets out there
surely earth can't be the only one so
perfect for life can it? On February 22nd
2017 NASA held a press conference to
reveal some very exciting news.
This is Trappist-1. It's an ultra-cool
dwarf star about 40 light-years away in
the Aquarius constellation. Astronomers
first discovered three earth-sized
planets orbiting the small star back in
2015.
NASA's exciting announcement? Not only
did they discover four new exoplanets
bringing the total to seven, but three of
those planets fall well within the
habitable zone of Trappist-1. Let's take
a look at the full roister. Here they are
in all their glory! Trappist B, C, D, E, F, G and H.
Not exactly the most elegant names but
we'll make do for now. Part of what makes
these planets so exciting is that
they're all rocky like Earth and they
all have a radius between
0.75 and 1.08 times that
of earth. Of these seven planets, e, f and g
orbit within the habitable zone. This
habitable zone is quite different from
that of our own Sun as Trappist is
significantly dimmer and less powerful.
This means that even though all seven
planets orbit closer to their star than
mercury orbits the Sun, the comparatively
mild radiation from Trappist still allows
for potential liquid water. As exciting
as that possibility is, it's important to
note these planets are suspected to be
tidally locked. When a celestial body is
tidally locked it always faces the same
direction,
much like the Earth's moon. That means
that one side of each planet receives
all the radiation from Trappist and the
other side remains in perpetual darkness.
Since Trappist-1 is so relatively
milder star, it's not yet certain whether
its planets would suffer from extreme
heat on one hemisphere and extreme cold
on the other.
However, even if that is the case, it's
thought that a proper atmosphere on any
of these planets would help dissipate
the heat and allow for a milder climate.
As fascinating as the discovery itself
is, what's equally fascinating is
considering what life would be like on a
Trappist planet.
What would it be like to stand on the
surface? One of the first things you
would notice is that the light is
significantly dimmer on Trappist planets.
Since Trappist-1 is an ultra-cool dwarf
star, most of its radiation is in the
form of infrared wavelengths rather than
visible wavelengths. According to NASA's
report, the day side of Trappist planets
would never get brighter than Earth's
skies just after sunset.
Once you got used to this perpetual
Twilight and looked out into space you
would see something remarkable. From any
given Trappist planet you would be able to
see most of your planetary neighbors
drifting across the sky and they
wouldn't be tiny specks of light like
Mars is to us. From a Trappist world you'd
be able to see the texture on your
neighbour planets, much like we can see the
craters on the moon.
Think about it, someday far into the
future residents of one planet could
look up into space and see the
crisscrossing lights civilization on
their neighbouring planet. Imagine one day
a child is born on Trappist-F. Since these
exoplanets are so close to their star it
takes in almost no time at all to
complete their orbit. That means that on
Trappist-F, little Johnny will be
celebrating his birthday every nine days!
As of right now we can't see the Trappist
planets directly to get detailed
findings on what their terrain or
atmospheres are like. Luckily with the
James Webb telescope launching in 2018
astronomers will be able to more
accurately determine the chemical makeup
of each planet's atmosphere. Newer
telescopes like the James Webb will be
able to assess the greenhouse gas
content of the atmosphere and give
scientists a better understanding of
surface conditions on the planets. The
ideal scenario would be discovering the
presence of what are referred to as bio
signatures such as methane or ozone.The
presence of such bio signatures would be
a strong indication of past or present
life. The star itself is classified as an
M-Dwarf star. This is extremely promising
for the possibility of life. An M-Dwarf
star is known for burning very slowly
and at very low temperatures, the lowest
of any other type of star.
This means that they can burn for up to
trillions of years unlike larger hotter
stars like our Sun which have a lifespan
measured in billions or tens of billions
of years.
What does that mean for the possibility
of life? Well, if Trappist-1 has been
providing warmth to its planet for such
a vast amount of time that means life
has had ample opportunity to emerge or
even develop into more complex forms. If
life is actually discovered in the
Trappist system, it bodes well for the
existence of life elsewhere in the
universe. Not only because we would have
found one example of it, but because
M-Dwarf stars are among the most plentiful
varieties of star. With billions of
M-Dwarf stars in the universe providing
warmth to billions of planets over
incalculable stretches of time, just
imagine the potential for life out there
among the stars. With the launch of the
James Webb telescope fast approaching,
we're into a very exciting next few years.
Imagine the significance of discovering
life in the Trappist-1 system. Not only
will the great question of "Are we alone?"
finally be answered, but the discoveries
we make on the Trappist planet would
dramatically increase our understanding
of habitable planets and pave the way to
greater and more frequent discoveries in
the future. Who knows, maybe the
discoveries we make in the next few
years will lead us to the greatest
discovery of all, a planet just as
suitable to life as Earth. It's all
incredibly exciting and Trappist-1 is
just the beginning.
These seven exoplanets are just a tiny
fraction of the confirmed number outside
our solar system.
Many of them are far stranger and more
exotic than the worlds of Trappist-1. You
can learn more about the amazing variety
of planets in the universe by checking
out this video by RealLifeLore where
he explores the incredible things you
could see and do it would be impossible
on earth.
Tthanks for watching and I'll see you in
the next video!