2012-03-25 12:11:20
In recent years, some space missions are dedicated to the identification of planets orbiting distant stars, to the discovery of other solar systems. There are even smartphone applications that notify when a new extrasolar planet is discovered and offer a database about them that is regularly updated with the latest findings.
This database contains fascinating information about the 759 extrasolar planets confirmed to date. For example, the database lists the distances of planets from their stars, and their masses. Many extrasolar planets orbit very close to their star and are extremely hot. Some are similar in size to our Jupiter, although they can be much larger. In fact, the largest discovered to date has a mass 37.5 times that of Jupiter. Others, however, are similar in size to Earth. These are the most interesting, since if they orbit at a suitable distance from their central star they could harbor life.
LIFE TEST
Obviously, finding at least one planet with life is the primary objective of these studies, which not only aim to find out if other planetary systems exist and their shape and frequency around different types of stars. These are interesting scientific questions, but their interest is less compared to the question of whether life exists beyond our beloved Earth, a topic that is not only scientific, but also affects philosophy and religion.
However, a major problem with science is that it is science, and not philosophy or religion. Science, if it intends to continue being such, cannot be satisfied with indications, ideas, speculations, or wishes. Science needs confirmed data, data that is as solid as possible about the reality that surrounds us.
The above means that it is not enough to discover the existence of an Earth-like planet orbiting a star like the Sun to conclude that that planet contains life. It is necessary to confirm the presence of life in some form. It is necessary to find out if the planet has properties that would only be possible if it contained life, including, among others, the presence of high levels of oxygen in its atmosphere, and the presence of water in large quantities.
This seems very difficult to achieve, considering that the closest planet discovered is more than 10 light-years from Earth, and in general, they are much further away from us. It is impossible to send any type of space mission to such worlds to check if they are populated by living organisms.
How could this problem be solved, if it can be solved?
ANALYZE THE LIGHT!
Fortunately, science aided by modern technology has unsuspected resources. Furthermore, the imagination and intelligence of scientists never ceases to amaze ordinary mortals, among whom I find myself regarding this topic, of which I am not an expert at all, but only a mere amateur.
A group of astronomers from several observatories had the brilliant idea of trying to find out if the light from the Sun reflected by the Earth, thus sent towards the Moon, and reflected back from the Moon to the Earth, contained information about the presence of life. on our planet. After all, light is a very important vehicle of information. Our visual system uses it on a daily basis, precisely, to obtain information about the world around us.
The interaction of sunlight with the Earth, as happens with any object, modifies it in a way that acquires information about the properties of our planet, including the presence of life. For example, the reflected light is much greener than that falling on Earth, due to vegetation. In addition, light becomes polarized when passing through the Earth’s atmosphere, another property that indicates the presence of life on Earth.
All this was already known thanks to the analysis of the light reflected by the Earth, captured by satellites in orbit. But if we want to know if the light that reaches us from a distant planet, after its long journey through space, can reveal the presence of life there, it is necessary to check if the light reflected by the Earth maintains information about life even in adverse conditions, such as, for example after being reflected again by its natural satellite.
Well, the light that the Moon sends us from its regions not illuminated by the Sun (for example when the Moon is in its first quarter) comes from that captured by the Earth and reflected back to us. Analysis of this light using various techniques has revealed that its properties continue to reveal that our planet contains vegetation, oxygen-rich atmosphere, water and life. These results have been published in the journal Nature.
Studies of this nature lay the foundations for improving light analysis techniques that we can capture one day from distant planets and determine whether they are full of life, like ours, or, on the contrary, are barren. Science advances step by step, surely; security that will perhaps one day finally allow us to answer the question of whether life is common or rare in our universe.
WORKS BY JORGE LABORDA.
One Moon, one civilization. Why the Moon tells us that we are alone in the Universe
One Moon one civilization why the Moon tells us we are alone in the universe
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