The search for extraterrestrial life is one of the most important science endeavours today.
Life started and evolved on Earth over millions of years in a wide range of conditions.
And if life could be present on Earth, it could be also present on other planets in
our universe.
The Search for Extra-terrestrial life or SETI is an organisation responsible for the search
of alien life in our galaxy and universe, but so far they have studied only a handful
of planets.
But finding life on any other planet, the presence of any alien civilization, is fascinating.
The moment we find evidence and proof that life exists outside of Earth, it would be
a tremendous breakthrough for mankind.
As Arthur Clarke quoted, “We are either alone in the universe or we are not”, and
both these ideas are equally scary.
If you want to know more, you could watch our other videos on Alien Civilisations and
their possibility of existence.
But today we will discuss incredible news that has just been announced by a team of
astronomers, perhaps one of the most important discoveries in decades.
Possible evidence for life has been announced on another planet Venus.
For many years scientist theorized that liquid water may be present on mars and later they
found small clues pointing towards its existence.
Today it is an undeniable fact that water is present on mars and was plentiful in the
past.
This is how we should imagine the process of finding extra-terrestrial life outside
the Earth, where tiny clues build into a humongous mountain of evidence.
And a few days ago we made a breakthrough and made a significant discovery.
But how could Venus harbour life?
Join us today in this exciting discussion where we discuss the exciting announcement.
What an exciting day marked by the announcement of a chemical marker of biology in the atmosphere
of Venus.
For many years humans have looked for life on mars as their best bet for finding life
outside the Earth.
NASA has invested a lot more money in sending Landers and Rovers on Mars than Venus.
The soviets on the other hand have sent a lot of missions to Venus and are also the
only ones to ever land their probe on the surface of Venus because of the scorching
high temperatures on the surface reaching over 500 degrees and a very high pressure
similar to a kilometre beneath the ocean.
So how could life possibly survive on the surface of Venus when even the Soviet probes
hardly survived a couple of hours?
In 2019.
a group of scientists published a paper about how we could possibly detect life on exoplanets
using bio signatures and how a chemical called Phosphine is very promising bio signature
for life.
Biosignature is just a way of saying that a particular chemical indicates life.
Oxygen is a classic example and is produced by the process of photosynthesis and I present
in our atmosphere.
Phosphine as a biosignature is certainly less studied but produced by anaerobic ecosystems.
We don’t know about any other process which produces this gas in such large amounts.
Therefore, detection of Phosphine in significant amounts on any exoplanet is a powerful indicator
that life processes might happen on the planet.In September 2020 a group of astronomers announced
a significant observation of phosphine in the clouds of our nearest neighbouring planet
Venus.
So how could life possibly survive on the surface of Venus when even the Soviet probes
hardly survived a couple of hours?
Well, things are hard on the surface, but if we head up into the clouds, the pressure
drops and the temperature becomes mild.
On earth we find microbial life in the clouds, up to 3 million tons of bacteria are lofted
up from the ground via air currents and fungal spores and micro-algae.
So the idea of life In clouds is perfectly legitimate.
And because of the thicker atmosphere of Venus, they remain there.
The atmospheric composition of Venus is almost made entirely of carbon dioxide and the clouds
are highly acidic composed of Sulphuric acid, where most life that exists on Earth would
immediately perish.
But not all!
We know many microbial organisms to have survive in such extreme conditions by evolving themselves.
When the soviets probes reached the hellish like surface of Venus they took photographs
of the surface.
In one of these missions they seem to have detected particle that was about 1 micron
thick, which is equal to the length of a typical bacterium.
There is an interesting theory that these bacterial like particle might be covered in
a molecule called S8.
S8 is a ring like chain of eight sulphur atoms which is impenetrable by sulphuric acid.
This might be possible that these bacteria might have evolved themselves and developed
a way to coat themselves in S8 and protect themselves.
This theory is not as offbeat as it seems.
Life evolves and survives.
On earth we can see life surviving against all odds.
On Earth we can see organisms surviving in highly acidic environments much like Venus.
So what can be other possible explanations and clues to this new discovery?
We think Venus might have been habitable in
the past.
But scientists guess that Venus had liquid water for around 3 billion years, only becoming
uninhabitable just 750 million years ago.
After that there might have occurred some global resurfacing events.
Venus resembles Earth, but it doesn’t have plate tectonics ad so all the internal heat
and energy within that planet had no way to vent out until it reached some critical tipping
point which ultimately ripped apart the entire surface.
But before that life could have been present on the surface and later evolved and adapted
the ability to survive in the clouds.
Astronomers could detect the presence of life on another planet without physically going
there.
They just have to look for the biosignature gases.
In this recent discovery astronomers used two telescopes here on earth which specializes
in observing the sky at wavelengths in between the radio and infrared part of the spectrum.
What the team found out was that the Venus’s atmosphere had an absorption feature which
indicated the presence of a phosphine molecule, which as we mentioned earlier is a positive
sign of existence of life on any exoplanet.
The amount of phosphine that seems to have been measured is in the order of 20 parts
per billion which is a tiny amount but comparing this to how much life it would require to
produce this, the amount seems significant.
But don’t get too much excited here.
We have to remain cautious and wait for the theory to be independently verified.
But even if we prove the team securely detected phosphine it doesn’t mean we have a direct
evidence or life.
Phosphine is indeed produced by anaerobic ecosystems but is also produced by other non-life
processes such as geochemistry and photochemistry.
Authors are certainly aware of this and argue that no chemical pathways are likely responsible
for this that is without life, but chemistry can be strange and complex.
And so there’s always a chance for the unknown.
So we should be cautiously excited about this discovery.
But we can definitely be sure of one thing, that this discovery is going to prompt a lot
of new inquiry into this area and also a lot of investments as NASA has focused little
on Venus.
After this, the most troublesome part is to really convince us that Phosphine has no other
source than life.
The chemistry that might happen in the upper Venusian atmosphere is very much complex.
Some of the biggest mysteries on Venus are the dark lines that wrap around the planet;
these lines are known to absorb UV light from the sun and can be found in the earth-like
band of Venusian atmosphere.
Could these be large colonies of UV absorbing organisms?
If you combine the ultraviolet light coming from the sun we have an opportunity of a process
called photochemistry.
Photochemistry is an awfully complex phenomenon and will take a lot of work to understand
whether or not it happens in the Venusian atmosphere and also to convince us that there
is no other way to make phosphine other than the anaerobic life process on Venus.
Because the production of phosphine is not very well understood, even here on earth.
We think it happens because of the organisms processing organic material like phosphates
and turning them into phosphine as a by-product, but we still don’t have a full picture of
what happens and leads to the ultimate thing.
The most convincing thing for us would be if we could get the cloud samples of Venus.
But it is not possible and a drawback of remote sensing because we cannot be presents everywhere.
We are just making inferences about everything after observing them, and this is hard when
we are talking about life on any other place outside of Earth.
People have proposed to the possibility of dropping balloon like payloads into the atmosphere
that can scoop up samples and then return them back to the orbiter which will bring
the samples back to Earth.
This idea is an easier one to implement than spending decades analyzing chemical models
and arguing whether or not life might be present.
And this news will renew people’s interest to know more about Venus.
Venus has long been enticing to us and this result is capturing the world’s attention
today and if indeed Venus has life, it would be a breakthrough in the history of space
Exploration.
But at the same time we should be cautious, because we should not forget Bill Clinton
on the white house lawn in 1996 announcing the discovery of life on mars, which today
is rejected by everyone.
But now e can re-analyze the data and collect new independent observations of Venus to check
if this claim is real.
If this discovery instils excitement in new Venus missions it’s a massive win for planetary
science and looking ahead if we confirm life on mars one day then we must solve the last
lingering question whose answer could change the way we think about ourselves in the universe.
Is the life on Venus an example of an example of an independent start to life?
Or maybe the life on Earth and Venus might be inter-related to each other.
Its quiet possible that all the life on earth originated from Venus, and this is known as
the theory of panspermia.
It suggests that life is spread throughout the universe travelling on comets and other
planetary debris, and if in case this life differs from the life present on earth it
will be a turning point in the history of mankind.
It might be possible that this life is not using DNA but some other form of biological
representation and many other aspects would be related to it.
And if that would be the case that would prove that there has been a second genesis of life
that has started in our solar system itself for the second time.
And if it can happen for two times in our own backyard, the universe would be teeming
with possibilities of life waiting out there to be discovered.
It might take some time for us to figure things out, but if we can prove the existence of
life, it would be the most exciting and historical thing to happen in the history of mankind.
So what do you all think about this new announcement?
Are you guys skeptical or excited about this discovery?
Let us know your thoughts and other questions in the comment section below.
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exciting news.
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