Since
past few decades we have been searching for any extra terrestrial bodies in the
universe that support life, similar to the Earth. It has been a subject of
human interest to explore more! Aliens, since this fictitious character known
to humans, had been widely discussed with a lot of interest all over the world.
Many eyes all around the globe are searching for just a little sign of life in
infinite space. Though writers and movie industries were benefited the most to
include them as a character in their work till now. Sci-fi movies and novels
including this fictitious characters are now-a-days most frequent far and wide.
These movies give a rough idea that how would it be like to meet an alien, some
of them depict that aliens are friendly whereas rest of them show them as our
enemies who came to conquer the earth. But the only question arises in our mind
is that “Do they really exist?”
Source: Google Images
Recently
NASA had spotted a very similar solar system as of ours. Scientists and Astronomers
are yet studying about them, and one amongst the seven planets of that solar
system is comparable to the Earth. It’s not the first time that NASA has found
such evidences. Hubble Space telescope, an eye in space, has helped NASA in
collecting many such evidences. All such discoveries are being executed as a
separate project and constantly monitored by NASA. Latest discovered solar
system is named as TRAPPIST 1. It has seven planets in orbit and the star is of
the same size as that of our sun.
Credits: NASA/JPL-Caltech
Source: Wikipedia
Even though
if we found any evidence of life, reaching there would not be so easy, as it is
39 light years away, which means if the light signals are sent from Earth to
those planets, it will take, for the fastest travelling thing in the Universe,
39 years to reach there! Again by any chance if there are any smart creatures
on those planets, to understand those signals and respond back, it will take 39
years more to receive their answer! Till then we might have been dead if there
isn’t anyone among us to survive till eternity. And yet God knows if
government will be still paying to work on that project! This leaves us with a
conclusion that yet if we recognize life on that planet; we cannot reach there,
using our recent technology. According to Albert Einstein no object with mass
can reach the speed of light, which makes it impossible to reach there, and even
if our Homo-sapiens brain could find
an alternative way to reach there, which again, say, will take about more than
a century, we are just on an assumption that life may exist in the cosmos on
planets other than the Earth.
Searching
just for water and land on any planet doesn’t mean that it is surely life
supportive. Water and land are the only primary two factors that can give a
possibility of life as we know it. There are millions of other factors that are
to be given secondary importance in search of life, thus reducing the
probability of their existence.
Talking
about the probability of life in cosmos, one might say that there are infinite
number of planets out there and one of them might be biologically active. But the
fact to be noticed here is that half of the stars are to close to the center of
a galaxy they belong to, where life cannot exist due to the presence of densely
packed star systems which might produce extreme physical conditions to support
life, whereas it does on earth because sun is at the outermost edge of Milky
Way. Other than that there are many Binary star solar system in the universe
which again cannot support life. Binary star system are those which have two
stars in a single solar system. Planets in such solar system have a complex
orbit, which is again repulsive to life because planets have to undergo extreme
weather changes while orbiting.
One more
essential condition for life to develop in a sustainable solar system is that
the age and size of the star heading that solar system should be accurate, most
probably same as that of our sun. Based on their birth and death stars are
classified accordingly. New born stars or baby stars have an ad hoc situation in their solar system,
where planets are not even in their correct orbit. Second stage of stars is as
of sun with a proper and well settled solar system. During the third stage
where most of the fuel of a star is exhausted they turn into a red giant. And
later either becomes a neutron star or a white dwarf. In a very rare case stars
form a black hole. Stars biggest of their catagories in the universe turn into
black holes. When star dies it is left with no fuel to keep itself to its
original size so it starts shrinking due to its own gravity. Neutron stars are
the smallest stars, only thousands of kilometers wide whereas white dwarfs are
a little more bigger than them, too cold to heat nearest orbiting planets. Conversion
of any star into a red giant indicates that life of the star is about to end.
Thus reducing the work of astronomers to explore certain specified solar
systems only!
Deeper into
a solar system, location of a planet is must. Too close to a star makes it very
hot whereas far planets are colder. Moderate location also known as Goldilocks zone of a planet is the most
preferred in search of life. After all these considerable factors, comes the significant
ones: land and water. Satisfying all these factors, on no basis will give
definite signs of life. These factors are followed by a sustainable atmosphere
with a suitable weather conditions which are not too extreme for a living creature
to adapt. The amount of elements present in the atmosphere also must be in
proper proportion. For example if there is excess of CO2 in the
atmosphere it will trap more heat, or absence of ozone will allow highly
destructive UV rays into the atmosphere. One more leading feature is the
magnetic field of the planet. It also plays the most important role in
maintaining weather conditions of a planet. All the above factors combined may
give us quite a small probability of existence of life. Searching for life in
space is much like searching a needle in hay.
Aliens are
not the characters recently created in the beginning of Space exploration. Ever
since the ages they have been in the Myths and Mythology of many tribes like
the Egyptians, Mayans, etc. But they are mentioned as helpers from outer space
sent by God. Their pictures reveal that they were very different from humans.
If it was so then, where are they now? Why aren’t they helping us, when humans
are on the verge of destroying this beautiful planet? According to these
stories they will come to help us when it is necessary, and may be the time
will come very soon.
But till now
we haven’t found any such creatures in space since the research began atleast
for more than half a centuary now. There are many questions in people’s mind
related to them like, when will we find them? What would it feel like, to know
that we are not all alone in this dark universe? How would we be able to
communiate with them? If there are such creatures in the universe, then are
they trying to communicate with us? Or did they already found us and are
keeping a watch over our actions? But the most important question remains, DO
THEY REALLY EXIST? Or we just got lucky with all the perfect conditions and we
are the only living creatures in the vast infinite universe!