Meteors that carry life forms

Generally, when we think of how certain complex things happen, we tend to think of complex ways to explain it. But, these complex issues may sometimes have very simple explanations.

The topic that we are going to discuss today is also such a concept.

Here is something exciting for you to think about. Have you ever thought of ways how life can move between planets, apart from the belief you have about using space ships and some other alien gateway? How about thinking of the ability of life to travel between planets using meteors as vehicles?

Going by the various experiments being carried out, this concept is pretty exciting. Even certain scientists believe that life on Earth came from a different world, packed in a meteor.

A lot of tests have been done on this subject, and scientists are revealing interesting information. So meteorites, while they can be destructive to life when they hit the Earth, can also create new opportunities for life to continue after an impact.

How can this happen?

Scientists have revealed that there is a possibility for life to travel on meteors to other planets. For your information, the theory of life travelling between worlds is known as Panspermia.

Just imagine a situation where a meteor strikes a planet and pieces of that planet flying into space as a result of the impact. It may not be a very large piece of the planet, but even a tiny piece of rock can jump into space in a collision between a meteor and a planet. These pieces can be attracted by another planet by its gravitational pull and these pieces would become meteors for that planet.

You may be aware that Earth has been struck by many meteors from outer space which are believed to be mostly from the Moon or Mars. In certain big collisions Earth had with meteors, pieces from Earth could have flown in to outer space and landed on our neighbouring planets.

No one can say no to this possibility. Certain scientists believe that life on Earth could have originated on Mars or even a planet further away and then brought to Earth by a meteorite.

Experiments

Scientists and astrobiologists are experimenting a lot on this concept under various aspects right now. When we talk of life, it need not be about just big creatures. Micro-organisms like bacteria are considered to be forms of life who can survive under extreme conditions.

Since they are so tiny, they can easily reside in any crack or on the surface of even a small meteor. But, there are many instances where they would have to face rigorous conditions.

According to a news item that appeared on the internet, Charles Cockell, a microbiologist at the Open University in the UK who was involved in this study has stated that, these organisms will have to survive atmospheric, the conditions in space, and also atmospheric re-entry when they reach the destination planet.

Scientists have experimented how bacterial spores (think of these as eggs of bacteria) can withstand the huge stress when they are driven out of a planet. They have found out that bacterial spores can withstand over one million G forces. G force is a measure of force.

You need not think of the exact meaning right now. They have also put bacterial spores in to bullets and shot them in to sand to find out how they survive under impacts. This has revealed that the shock has not killed the spores and they can survive high impacts.

This result has shown that bacteria has a big chance of surviving when the meteor lands on the planet. Further experiments have been done to check how micro-organisms can face shock pressures. For this, micro-organisms have been put between two plates and a small explosion has been done to shock the plates together. The microbes had survived.

This has made clear that certain micro-organisms can withstand the heavy pressure of being ejected from the planet as well as the impact of landing.

But, they still have to experiment how these organisms would survive during the journey in outer space.

The most important concern is how the organisms would withstand the immense heat generated during entering a planet's atmosphere. One idea is to have the bacteria or whatever micro- organism inside the meteor, so that they would get less affected by the heat. But, still this is considered to be a strong barrier in spreading micro-organisms among planets.

Aravinda Dassanayake