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Astrobiology - Black plants and twilight zones / Bryn Nelson

A distant planet challenges the theorists and stimulates them to think deeply about extraterrestrial life

The six-planet model of Gliese 581
The six-planet model of Gliese 581

Astronomers have been searching for a long time for a planet outside our solar system that could support life. The reports that arrived in the early fall of 2010 about the exoplanet, Gliese 581g (581g), which is neither too hot nor too cold, were like a dream come true. "If the report is confirmed, I think this is the planet we've been waiting for for a long time," says Roy Burns, an astrobiologist at the University of Washington who was not involved in the study.

But we may have to wait a little longer. Immediately after astronomer Steven Vogt of the University of California, Santa Cruz, and his colleagues reported a "golden planet" (the Three Bears constellation), a rival group in Switzerland was quick to announce that there was no evidence for the existence of Galisea 581g in its data. Confirmation of the new finding, which is based on 11 years of sensitive and indirect measurements using a telescope, will probably take a few more years.

But the tantalizing data has already encouraged the astronomers to advance their research about the necessary conditions for existence of life outside the Earth. The possibility of the existence of Galiza 581g is, according to them, an injection of energy to build sophisticated models using supercomputers that will demonstrate life on other planets that are similar in size to Earth.

Scientists, including theoretical physicists, combine astronomical observations with the knowledge of life we ​​know on Earth to build computer simulations of the extraterrestrial environments. Now, amid a wave of discoveries of such planets, realistic models could provide important guidance for future space missions that will search for signs of life in the universe. Recently a 581g slide was made for this research focus. Its almost circular orbit around a red dwarf type star places it at exactly the optimal distance for temperatures that allow the existence of liquid water on the surface - a necessary sign of life. But the red dwarf emits little light, only 1% compared to our sun. It is likely that photosynthetic creatures on its surface will try to absorb as much light as possible from their star. Such plants will have a black appearance, according to the model of Nancy Kiang of NASA's Goddard Institute for Space Studies in New York and her colleagues at the Virtual Planet Research Laboratory at the University of Washington.

Preliminary calculations also support the view that Glyza 581g always faces only one side of it towards the Sun. This side will scorch with temperatures reaching 64 degrees Celsius, while the dark side will have a brutal winter like the North Pole. This angle, which is still in dispute, may leave a strip of "eternal sunset" conditions, as Vogt calls them, that are more suitable for life. If this hypothesis is confirmed, the light falling on each longitude will be of a different wavelength and this will cause, according to Kiang, plants in the colors of the rainbow due to the different pigments (pigments) that will be adjusted to the light that washes the surface.

Apart from the breath of life that Galiza 581g has breathed into theorists, it has also whetted the appetite of astronomers hoping for hundreds of similar discoveries outside the solar system. "Either we've been very lucky, and we won't find another one for a long time," says Vogt, "or there are many of them out there."

19 תגובות

  1. Avi:
    really read
    I also read it and the idea you brought up in response 16 is correct and interesting.
    Regarding improving the odds calculations - I would not go into it for two reasons:
    1. Even in the current Drake formula, you can get any result you want (and this is because a lot of values ​​used in it are unknown).
    2. Today we still have quite a hard time discovering planets outside the solar system and we have not yet reached the discovery of moons.

  2. Thanks for the correction Max Power, "in the heat of writing" I didn't notice that I didn't mention Saturn in the sentence - but it's nice to know that people are reading your comments 🙂

  3. Commentator 16 Mr. Cohen The moon Enceladus orbits the planet Saturn, the idea is generally correct.

  4. The question is whether methane concentration can be created by a geological rather than a biological process.
    In Europe we have to go through a very thick ice sheet to reach the ocean we suspect exists there. The important thing to understand in the case of Europa and Enceladus is that the energy that heats them does not come from the sun, but from the gravitational tidal forces exerted on them by Jupiter.
    If in the future we manage to overcome all the existing technical obstacles, and discover life there, this greatly increases the possibilities for other life forms throughout the universe. Today, most of the planets we find are gas giants (this may be due to the technical limitations of the methods of discovering the planets that exist today), and if there is life on the moons of gas giants, there is a chance that we can find them there as well.
    Does anyone know how to calculate how much the chances of finding life increase if there is life on the moons of gas giants?

  5. There is an unexplained methane concentration gradient on Mars that raises the suspicion of microscopic life there.

    And there is Jupiter's moon Europa and Saturn's moon Enceladus which are actually balls of ice and it is possible that within them there are warm areas with life forms similar to those in the smokestacks of the central oceanic ridges here on Earth. (In Enceladus there are literally geysers of ice in the south pole that hint at internal heat)

  6. Yehuda,
    I agree with you that we should not conclude from the life forms on Earth, which are the only possible life forms in the universe, for the simple reason that it is not possible to conclude from the characteristics of any individual, that they are statistical predictions about the rest of the group. It is very possible that we are actually the exceptions in terms of life forms that exist (if they exist) on other planets.
    In my opinion, we suffer from some kind of arrogance in relation to our perceptions of ourselves. In the beginning, God was the center of the universe and we are the crown of creation. After that we realized that we actually revolve around the sun, but the other stars probably revolve around us. After that we realized that we are at the edge of the galaxy and not in the middle, and in general, our galaxy is just one of many and not at all special in a universe of enormous dimensions. Little by little, we are leaving the center. Today we are beginning to understand that it is very possible that we are not the only planet that sustains life, but still "we are the only intelligence in the universe-the tiara of creation."
    "But" and it's a big but, unfortunately, we don't have any other point of reference at this time, so the only life forms we know are here, and currently they are the only point of reference.
    Therefore, if we plan a study to explore life on other stars that costs millions of dollars, and thousands of hours of work, we will try to rely on what we know for sure and not on what we believe or speculate, and that is that life forms can develop on Earth-like stars.
    The options are as follows:
    1. Kaduha is the only planet with life.
    2. Kaduha is a unique planet in terms of the life forms on it, and in the other planets life developed in a different way.
    3. As Earth and the life forms on it developed in a similar way to life on other stars.
    4. Earth and the forms of life on it are similar to some of the forms on other planets and different from some of the other forms.

    I believe it's option 4, but I really don't know for sure.

  7. Yigal c.
    These key words signify their fulfillment in all the planets and moons.
    Of course, the expression "enough time" is a possible refuge in any situation where you will not find life, but if you are talking in terms of the time when life was created on Earth, then all the planets had already had more than enough time.
    That's why I said that the conclusion from your words is that there is life on all the planets and moons and I asked if this is what you think.
    Reproducibility does not exist wherever there is chemical activity. It is also important what the possible chemical activity is.
    Therefore, in my opinion, there is quite a bit of exaggeration in your words.
    It should also be remembered that there is a difference between the situation in which already formed life adapts to conditions of a certain type and the possibility of life forming in this particular type of conditions.
    Evolution can allow existing life to adapt to a wide spectrum of situations and conditions, but this does not mean that in any combination of these situations and conditions life can arise in the first place.

  8. Mr. From response 9: Key words in what I wrote are "possibility of chemical reactions" and "enough time". And again, the term "life" should be expanded and redefined. And to your question, yes, I think that the power inherent in the ability to reproduce results in the appearance of life in a much wider range of conditions than is commonly thought.

  9. M*CXL
    Note that Gael wrote the word "apparently" so you should keep looking. But I believe that soon there will be life on all planets. We have already polluted the moon with all kinds of spores and in a short time we will no longer be able to distinguish whether the animal we discover is a local product or our import.
    Good night

  10. Yigal C:
    If we take your words in response 2 seriously, then from the sentence "life will probably appear wherever there is a possibility for chemical reactions and where there will be more or less constant conditions for a long enough time" it follows that there is life on all the planets and moons in the solar system and you don't have to go far to find it .
    do you really think so?

  11. A nice story indeed. I understand now why they don't let the master of the stage here anymore.

    Yom Tov Sabdarmish Yehuda.

  12. Yehuda,
    Your story is indeed very nice. But you Vigal ignore some simple points:
    1) In order for there to be life there must be chemical complexity.
    2) In order for there to be complexity, macromolecules need to be formed (such as in our case proteins and nucleic acids, but of course this is not mandatory and it must be assumed that many other macromolecules will be the basis of life).
    3) From a chemical point of view, there is a relatively narrow window of temperatures and pressures that allows the creation and stabilization of macromolecules.

    Just look at the difference between the diversity of life in Antarctica and the deserts on the other side and that in the temperate regions. Have you ever wondered why there is no diversity of life in Antarctica?

  13. Karchoni and R.H., there is nothing to "believe" here, nor to look for "guys" with whom we can interact.
    Life embodies additional things to these. The meaning of the term "life" should be much more extensive than usual and it should include everything that is created spontaneously and reproduces during development with the possibility of mistakes in the reproduction phase. The ability to develop intelligence is embodied in this process.

  14. Yehuda Vigal,

    It's not accurate. In order for there to be life, you probably need a large molecular diversity. Such a variety exists only in a relatively narrow temperature range. In the sun or even Jupiter there is no variety of gaseous and solid liquids and conditions that allow the variety of reactions seen on Earth. From a chemical point of view, these stars are much more "boring", so it is hard to believe that life would be created there.

  15. Yigal and Yehuda, even if you are right, you can elaborate and say that the researchers are focusing on life forms that are more similar to us (relatively) and that we could have some kind of interaction with them..

  16. Yehuda, I'm with you. The determination of the researchers on the subject is really unlikely. Life will probably appear wherever chemical reactions are possible and where conditions are more or less constant for a sufficient period of time. The organic molecules discovered in space indicate, perhaps, life that has a common basis for life on Earth, but it is possible that other molecules found in space and perhaps even in larger quantities than the organic ones, indicate life on a different basis that we do not hypothesize. The great power inherent in self-replication leaves little doubt as to the explosive potential of life in the universe.

  17. Again and again it is spoken as if life is only an earth-like life and it has already been proven that life is capable of being in a huge range of temperatures of hundreds of degrees and pressures of thousands of atmospheres.
    The claim that life needs the sun for its existence is also a claim that is unacceptable to me. I'm sure life would be fine on just a warm planet. The earth sustains a fruitful life precisely in chimneys in the depths of the ocean where no ray of light from the sun reaches and I imagine that these chimneys have been emitting heat for billions of years.
    Good night
    Sabdarmish Yehuda

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