Sailboats Sale Chicago Astrobiology

June 15, 2009

Astrobiology.

Juan Fernando Sanin

Note 2.

As the only life we know is that of the Earth, the definitions have been through the centuries, are related to terrestrial life . CH TMLXC

remember that at school I was taught that a living being is one who is born, grows, eats, reproduces and dies . It is a good definition, but it lacks the modern terms to describe each of these stages. In addition, one might argue that hybrids, like mules do not reproduce, surely this idea will cause controversy. Of course, now the mules could reproduce by cloning, but have not yet done the experiments and the respective findings.

The same definition, but in scientific terms might be: A living organism is a physical system that grows through reproduction, metabolism and adaptacióny that is capable of responding to stimuli . A third more sophisticated definition would be: A living organism is one that is able to reduce its entropíaa expense of substances or energy environment. Another even more complex: Living organisms are self-perpetuating chemical physical systems of chemical reactions catalyzed organiccomplex, which itself is produced by the system.

The four definitions of a living being above are equivalent, but the former is more understandable for those who are not physicists, or biologists. The fourth definition gives us a broader vision that would allow us to recognize living organisms in space, which may not be known on Earth.

In any of the four definitions is implied some propertieslife, which also will help astrobiologists to recognize where to find it. These are:

1. Homeostasis: internal regulation to maintain state. Eg sweat to keep warm.

2. Autopoiesis: The ability to continuously regenerate itself.

3. CH TMLXC Metabolism: Conversion of substances to produce new components (anabolism) or to destroy those that have (catabolism).

4. Growth: Faster anabolism to catabolism, at least in the early stages of life. Tamanoo means increased capacity to produce more than destroy components.

5. Adaptation: The ability to change in response to environmental changes. CHT MLXC

6.

Response to external stimuli, such as geotropism or heliotropism.

7.

Reproduction: Capable of producing nearly identical copies of themselves. The sexual reproduction is not necessarily because it is known that in plants is more common asexual reproduction and also experienced success in cloning animals. CH TMLXC

is so complicated the concept of being alive, even on earth there are living beings who do not fulfill all these properties. Such is the case of viruses, which have no metabolism and reproduced at the expense of other living beings. The same happens with humans in a coma, unresponsive to stimuli.

chemical conditions for life

chemical elements that help shape and sustain life must be followed thementities characteristics:

1.

should form molecules that are neither too volatile nor too stable. 2.

must have internal energy, usable by the body. 3.

should be dissolved in some way to get around and find each other and produces chemical reactions. 4.

must be found in adequate amounts to ensure growth.

Life on Earth is mainly based on carbon. The silicon and boron partially meet the conditions listed. It is likely that a life based on silicon or boron, has similarities but also differences with the life that produces carbon. Elements such as hydrogen, oxygen, sulfur, phosphorus and halogen alson satisfy the above conditions and also are a source of energíay animation.

What is the medium that allows the mobility of these elements? The most obvious is liquid water, although there may be others. Therefore, life as we know on Earth, is closely linked to liquid water, to the point that we can sense that there is water, there may be life.

But not only the environment that water would be conducive to life. There are compounds such as ammonia, which, under certain conditions, could also serve comaparicióny or medium for the sustainability of life.

For all these reasons, the search for extraterrestrial life, but is closely associated with what we know on Earth, may have strange ingredients, which hinder their recognition. Hence the need to revise the concept that we have had for centuries, so that our search is not frustrated, or, to a manifestation of life, to reject it because it is not 100% like we know it as such .

If a planet is found that:

A hardware for life. liquid water exists.

has abundant carbon, hydrogen and oxygen.

This planet or moon would be a good place to try to find extraterrestrial life.

Astrobiologists are clear, most likely, if there is life in space, it will have common factors with the Earth, iero also differences. As for intelligent life, future exoplanetary findings might show that the appearance of these beings, if we manage to contact them and see them, could be very different than terrestrial humans. Most likely not be like the gray man, with large eyes, whose image is universalized, after Rostwell flying saucers.

In the next post will discuss the possibilities of finding life within the solar system.