Now if you see life from outer space than one question raise in your mind that How did life begin on earth? This is a fascinating question. We know that life began on about 3.85 billion years ago.
The Idea of Began Life
Now where did it began? Some people think that maybe in the shallow pond is present at the beginning or where water was standing on the surface, was the place where life began.
In fact one goal of ‘Perseverance’ rover which is exploring Jazero Crater is to check whether some evidence of Protolife is present there. Some other people think that maybe life started near the volcanic vents present under the Sea and this type of volcanic vents are present in the seas of ‘Enceladus‘ (moons of Saturn) but there is another fascinating idea is maybe came from outer space. This idea is called Panspermia.
Proof Life of Outer Space
NASA did a press conference on 6 August 1996. This it is an important press conference and actually it was significant because NASA announced at that time there is a rock of Mars named ALH84001 and we think on that rock for the first time was we have obtained proof of ancient life at some other place I mean in outer space that is on Mars.
This was big news in fact, the President of the United States at that time, President Clinton, did a press conference and said if this is theory is proved (because it had to be checked by other scientists) then it will be a very important discovery.
Proof for was life from Mars ?
This rock is found in area Allan Hill of Antarctica that is why it is called ALH,
This was discovered in 1984 that is why ALH84 and this was the first meteorite of that year. This is the story of its name why it is called ALH84001.
In the early 1990 century, scientist analyze this rock and they found multiple lines of evidence suggestion that maybe there are signs of ancient life of Mars in it. First of all, you will ask ‘JUST A MINUTES’ how do we know this rock came from Mars? This is a good question. Let me say that scientist do not have any disagreement among them regarding this matter. This is clear that this rock is really from Mars.
Actually this rocks was a part of Mars and a long time ago another meteorites collided with Mars due to which this rock ejected from Mars and it ejected so fast that is escaped from the gravity of mars and eventually landed on Earth. When that meteorite collided with mars this rock melted a little due to the heat of the collision (friction) and solidified after some time.
Between the smelting and solidification, a little atmosphere (air) of Mars was trapped in it in the shape of bubbles. Right! Now there are small bubbles of air in this rock ALH84001 and scientist analyzed these bubbles and came to know that its composition is the same as that of the atmosphere of mars.
This is a mind boggling a fascinating thing that we can find out what is the origin of that rock, so there is no disagreement that this has come from Mars. I know there were different pieces of evidence as to why scientists thought there were remains (fossils) ancient life in it. Not life, but remains of ancient life and also that may be some fossilized remains may be visible.
But I want a period of time we are talking about 1996 many scientists said though this is very interesting but the proofs are not so solid because maybe what we are saying is not the biology but chemistry so there was a lot of debate among them about whether remains of ancient life on Mars or president or not on ALH84001.
But if today you are most astronomers they will probably say no. This is good., because, as there are claims of UFOs when people say oh what did I say I don’t know maybe it’s alien spacecraft, so you can see when scientists actually analyse these sorts of things they do it very carefully because this is a very big claim. And this arrival of a Martin rock to earth is not something very surprising.
How Many Meteorites On Earth From Mars
Up till now, human have discovered 60 to 70 thousand meteorites (rocks) coming from space on Earth. Out of this, a teeny fraction a little above hundred are from Mars
And I think some rocks of the Earth must be present on Mars also. But just think that if life began on Mars a few billion years ago, maybe even before the beginning of life on Earth and if this type of rock containing life came to earth then maybe it seeded life on Earth. We are talking of March but a similar idea is called PANSPERMIA.
Idea of PANSPERMIA according to Mars Life
The idea says that it is possible that when life or series of life present on asteroids or comets or dust particles crash on such a planet where conditions are suitable for the development of life then life will begin there. This idea is called PANSPERMIA, but let me clarify that up till now we do not know whether this idea is correct or not. In a way this idea looks crazy but let me tell you this is not completely crazy for some reason it is an intriguing idea and may prove correct.
Why is this Panspermia idea appealing?
Because we know the element of which our life is made of carbon hydrogen and oxygen nitrogen are very common in our universe. Not only this but complex organic compounds such as amino acid, glycine are also present as we know own comets and asteroids.
Similarly, phosphorus which is an important component of our DNA is also present. Some sugars such as xylose or arabinose have also been discovered on comet etc and then ribose which is very important for ribonucleic acid (RNA) that also has now been discovered in space.
Up till now, we know that, not life itself, but the building blocks of life have been found in different places especially on asteroids and comets. Now they are present on asteroids and comets then how will they reach earth.
Well, we know comets and asteroids have been colliding with art because there are a lot of creators present here. In fact, at the beginning of our life, there was an age of bombardment in which a large number of comets and asteroids had come and collided.
So if this type of building blocks were present, maybe they brought it to earth. But Panspermia says not only building blocks of life maybe life, but it’s its also come to earth in this way. Leave aside comets and asteroids, every day interplanetary dust (cosmic dust) fall on Earth’s atmosphere approximately 100 MT falls daily on our atmosphere and a little fraction of it reaches earth also.
Some controversial ideas are there Two astronomers Fred Hoyle (now dead) and Wickramasinghe think that maybe there is life in the interplanetary dust what it brings here. So Hoyle and Wickramasinghe, since 1970 are proponent of this panspermia idea and they say that in space, there are not only building blocks of life but according to them actual life is also present.
How Life Began on Earth
Our life on Earth began this way that some comet and asteroid brought the seed of life here and then because the condition on earth were favorable for life, so life developed, evolved, and now today, you and I are talking about it.
But the idea that this type of life (not one causing disease) what does ignite mean in space and came here from there like as Mars life. Fred Hoyle and Wickramasinghe have a big hand in promoting this idea.
Significant Objections regarding Panspermia
There is one significant objections regarding panspermia that, Ok if life is there on asteroids, comets, or on those dust particles, how will it survive the harsh environment of space? This objection is very correct.
But now even on earth, we are slowly finding out such life forms, which stay alive in extreme temperatures. Among them, one, which is famous and fascinating is a small animal named ‘TARDIGRADE’
These TARDIGRADE survive in extreme temperatures that is if you go in the extreme cold these TARDIGRADE survive even in -250 degrees centigrade(which is near absolute zero) because they go into a state of cryptobiosis they slow down their metabolism and when conditions return to normal, they become normal as well.
Not only in cold but TARDIGRADE survive an extremely hot temperatures also almost 150°C which is much more than the temperature of boiling water. Not only this, a harsh radiation environment 1000° more than the little dose, is lethal for us, but is no problem TARDIGRADE.
TARDIGRADE can survive in space
This is an interesting life form which can survive in space. In 2008, a European mission took these tardigrades into space and on the return checked, whether they survived or not and in fact, those who returned what in the state of stasis.
Not only does that they came back birthday important thing is they had offspring’s (children) meaning their line could continue, one mission of tardigrade was in Israeli mission which was going to the moon with tardigrades (a few years before) and it crashed on the moon. Now these tardigrades are present on the moon and who knows when we go back to the moon we see a colony of tardigrades. The chances are slim, because the condition over there are such that will not thrive there, but can survive there.
TARDIGRADE are fascinating creatures and because live on Earth is linked with one another through evolution so it is possible. There may be other creatures of this type that can survive in the extreme environment of space.
Good Size is a combination of imagination and good testing so I think this Panspermia is a fascinating idea, but up till now we do not know if it is correct or not. More testing is required for that.
But before finishing, I will see up in now we have been saying that life came to earth from somewhere else. But now the space exploration is being carried out and human spacecraft are reaching other places such as on Mars. When they go there, we should see that they are properly sterilized because the danger is our own life forms (once which can space combinations) may get introduced there and (who knows) take over, such a place where there is Local life.
I am only talking about robotic spacecraft now. After sometime, humans will also start going to other places. Then we will be taking not only our life (human life) but the whole microbiome, to another place. So space exploration is a good thing but with that, responsibility is also necessity.