Researchers from the University of Auckland in New Zealand say that they have developed a new method for discovering Earth-like planets and that they estimate that the number of these planets may reach 100 billion
The strategy they used is known as gravitational microlensing, on which a joint Japan-New Zealand telescope known as MOA (Microlensing Observations in Astrophysics) on Mount John in New Zealand is based. Their work was published in the Journal of the Royal Astronomical Society.
The group led by Dr. Phil Yoke from the Department of Physics at the University of Auckland explains that the work will require a combination of data from gravitational microlensing observations and NASA's Kepler space telescope.
"Kepler discovered Earth-sized planets but only those that are very close to their parent star, and it is estimated that there are about 17 billion such planets in the Milky Way. These planets are hotter than the Earth, although some of them may have temperatures similar to the Earth and therefore may also contain life, if they happen to orbit a cold star of the type known as a 'red dwarf'."
"Our idea is to measure the number of planets with a mass similar to Earth orbiting stars up to twice the distance between the Earth and the Sun. These planets will be colder than Earth. By matching the Kepler and MOA data we can get a good estimate of the number of habitable Earth-like planets in our galaxy. We estimate that the number will be in the order of 100 billion. Of course, there will still be a long way from counting these planets to actually finding habitable planets, but this is a step in the right direction," he said.
The first planet orbiting the Sun and similar to Earth was discovered only in 1995 despite tremendous efforts by astronomers. Dr. Yoke explains that this fact reflects the difficulty in remotely detecting non-luminous objects such as the Earth surrounding a bright object like the Sun. The planet is lost in the star's glow, and therefore indirect methods were required to discover these planets.
While Kepler measures the loss of light from the star when the planet orbits it and passes between us and the star, the gravitational microlensing method measures the deflection of light from a distant star that passes through the path of light from the distant system to Earth - a phenomenon predicted by Einstein in 1936.
In recent years, the method has been used to discover several planets the size of Rahab (Neptune) and Jupiter. Dr. Yoke and his colleagues proposed a new way to use the gravitational microlensing method to detect the tiny deflection created by a planet the size of the Earth. Simulations carried out by the members of the group with the reinforcement of researchers from France - showed that Earth-like planets can be discovered more easily if a global network of medium-sized robotic telescopes is built to track them simultaneously.
By chance, such a network of telescopes with a diameter of 1-2 meters Las Cumbres Observatory Global Telescope Network (LCOGT) is being established in collaboration with St Andrews (Scottish Universities Physics Alliance) which includes three telescopes in Chile, three in South Africa, three in Australia, one telescope in Hawaii and one in Texas. The network will be used to study gravitational microlensing events in conjunction with the John Moores University telescope in Liverpool located in the Canary Islands.
It is expected that data from these telescopes will augment measurements at the existing MOA telescope on Mount John, and additional telescopes in Chile and Tasmania.
The paper was published in the Monthly Records of the Royal Astronomical Society.
The article will be published in Monthly Notices of the Royal Astronomical Society. (DOI 10.1093/mnras/stt318.)
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Eric L's long response is the most accurate I've read from what we know from the National Geographic films.
In my opinion, they should have really complicated the criteria for a land-like and include things such as: and it has independent volcanic activity at a moderate level, which allows for the creation of a permanent atmosphere, and in addition a magnetic field, which protects against solar radiation. If such parameters can be measured remotely. It seems to me that it is not possible because otherwise they would have been measured. In the method suggested above, Mars is also Earth-like. That is, out of these, a second scan is required that will apply a more country-like criterion.
You guys are fun…. Miel -,_
Abi, there is no doubt that what you described is their intention "in the form of XNUMX" - in the article itself it is written that what characterized the difficulty in finding these stars is the fact that they are not bright.
And still 100 billion of this type of stars is very encouraging since the probability that among them there will be some that contain life is reasonable
Eric L,
The question here is what do they mean when they say "like a God"...
According to information I read on other websites, it seems to me that the reference is not to planets bearing life on them, but to planets in the category of the earth - terrestrial, as opposed to, for example, gas giants, or "super terrestrial". This category includes both Mars and Venus.
So when they estimate 100 billion planets, they include Venus-like stars, Earth, Mars and other possible variations. The question is what English term did they use in the original article.
Regarding the development of life forms, we do not exactly know what the main mechanism is responsible for the development of a large variety of life forms, and why in certain periods there is an explosion of new life forms, or massive extinctions...
In addition to this, when we talk about the existence of life, we are also looking for simple life forms like unicellular, and not only developed ones like humans. Therefore, a planet with a static and safe environment is also a point of interest in terms of looking for life.
You also mentioned that such life would be in danger of extinction from some kind of catastrophe, but if there were catastrophes in such an environment, then the environment could no longer be considered "static and safe", and then the catastrophes could cause the evolutionary changes that would improve the species.
GUY
The tides certainly affected life on Earth. But that says nothing about other stars. No one has any idea what the effect of tides is on the development of life, compared to development without tides.
Hey
The Earth has what no other planet has - as far as I know, and that is a satellite with a mass of one sixth = the Moon. As far as I know, KA is extremely unusual because of this, and I also read a theory that it was the tides caused by the moon that led to the emergence of life from the water to the land. I think it would be interesting to check it out.
NASA, please put the test results in writing on the science website by next week, thanks 🙂
Eric L
I understood what you are saying. Makes sense.
Sorry, a slight correction - actually both the moon, which relative to the size of Mars is quite close to the size of the Earth, and also the mini-planet Sirius, are located in the golden zone, which means that 80% of the planets / moons located in the golden zone in our solar system are lifeless and unconditioned for life
Nissim, I tend to agree with you. In connection with your first lament, the intention was that originally the earth was not in its current state - flowing water, an atmosphere with a comfortable temperature for organic chemistry processes, etc. According to the currently assumed model, the Earth was for hundreds of millions of years with a completely different atmosphere and a completely different temperature to what we understand today as an environment suitable for life. As fate would have it, out of the three planets located in the "golden zone" as defined by scientists - Venus, Earth and Mars - only Earth currently has life, and only it is defined as a planet welcoming to life. At the time I read that if Venus had not gone through the greenhouse process it went through due to extensive volcanic activity in the past, the temperature on it (a function of distance from the sun + reflection of solar radiation) should have been about 4-5 degrees higher than Earth. And if Mars had a magnetic field that would have prevented the erosion of its atmosphere by the solar wind, it would have been "only" 10-15 degrees colder than Earth. That is, in this situation, even if we assume that life would not develop on these planets due to some peculiarity of the Earth, we could still find ourselves with 3 planets that at least support the existence of life. That is, a position in the golden zone, a correct mass (Nega's mass is 0.9 that of the Earth) does not necessarily guarantee the existence of life or the existence of favorable conditions for life as we know them on Earth.
Here, our solar system as an example, 66% of all the planets that exist in the golden zone and with a mass very close to that of the Earth, are frozen or hot wastelands without life or conditions that allow the existence of life as we know it.
Eric L
I agree if what you say, but there is always a but....two even
The first is simple - you said that in the beginning the conditions on Earth were not suitable for the existence of life. But, they may have been very suitable for the formation of life. This is an unfounded opinion, but we know that life began when the Earth was a billion years old. Maybe such conditions are necessary for the beginning of life?
The second is more complex. I believe that one of the conditions for the success of the evolution process is actually a constant change in conditions. Constantly - but at the right pace.
I think so for two reasons. The first is completely rational: without a change in environmental conditions, creatures that are a "local maximum" may develop. Sewell Wright wrote about a "service landscape" that has mountains and valleys. If the environment is static then life will reach some peak of the landscape and stay there. Not many species will develop and any catastrophe could destroy all forms of life. Changes in the environment can improve life forms, similar to a process called annealing. The second reason is empirical - we know that there were periods of a jump in the number of species and periods of slow changes. I believe that these periods correspond to changes (at the appropriate rate) in environmental conditions.
Miracles, the meaning was that our planet was originally not suitable for life, and even today it remains so mainly thanks to being geologically active but not overly so.
For example, Venus was supposed to allow life to exist similar to Earth. But due to too much geological activity, it was filled with greenhouse gases, which created an impossible temperature for life to exist there.
Mars, on the other hand, is an example of a planet that, due to geological inactivity, its magnetic field ceased to exist, and thus the solar wind could erode its atmosphere and lower its temperature to its current state.
Earth, however, is in a unique situation. On the one hand, it is very exposed to influences from the sun, similar to Venus and similar to Mars, so it could easily reach a similar state to these two planets.
On the other hand, all its geological activity, or its internal engine, depends solely on it - that is, it is not driven by any external engine, and therefore can easily stop working or overwork.
In addition, life itself apparently changed the earth to the state it is in today - whether in terms of the concentration of salts in the oceans (which was supposed to be much higher), or in terms of the concentration of oxygen and greenhouse gases. Therefore, the unique chemistry of life has preserved our planet as suitable for life as much as its internal engine. Even if the internal engine would cause too much destruction to life, and this preservation mechanism would be destroyed with it.
This is compared to life that could exist on Europa's moon. In such a model, there is no dependence on the star, under an ice shell of tens of kilometers at minus 200 degrees, no radiation affects life that developed there. In addition, the vast ocean there (2-3 times the volume of the oceans in the Earth) remains warm as a result of gravitational interaction with Jupiter, and not as a result of internal geological activity that may be unstable.
In addition, life there will likely be much more resistant to mass extinctions such as the dinosaurs, caused by meteors.
So even though on the face of it, the area of the solar system where Europa is located seems clearly unlikely for life to exist, there is a possibility that in the universe, these places are much more common with life on them than the Earth, which is supposedly located in the "golden zone" of our sun, but could easily find itself with a destiny like Mars or Venus.
Asaf
What Eric L says, among other things, that there may be such a star in our solar system. The chances of finding evidence of life at great distances is small. It is not zero because there are indeed methods to discover life from a distance.
Talk talk... before they find at least one planet worthy of habitation, in the meantime everyone presents beautiful numbers without evidence in the field.
p.s. Why do I need to fill in the email and website fields to post a comment?
Eric L
I'm not convinced you're right. There is life on Earth starting around a billion years from the formation of the star. Life has lasted for 3.5 billion years and will probably continue for at least a similar period.
It is precisely the changes in our living conditions that have led to rapid evolution. Static conditions are less good for development - there is a greater danger of a "local maximum".
Of course you could be right...
The definition of where life can be sustained is very, very problematic.
In fact the Earth in its unique form is probably much rarer than the other life-bearing planets in the universe.
Earth was originally a very inhospitable place for life as we know it today. In addition, the fact that even today, for billions of years, it remains hospitable to life, is a fact that is not obvious at all. So I don't know how to estimate that Earth-like stars are so common in our galaxy. It is enough for the Earth to cease to be geologically active, and our fate will be similar to the fate of Mars due to the destruction of the atmosphere by the solar wind.
And enough that there was more volcanic activity on Earth, and our fate was like Venus.
I think that a model similar to what is probably happening right now on Europa's moon is much more likely: a large moon that surrounds a gas giant, much less sensitive to atmospheric changes because of the great distance from its star, and is completely covered in ice as hard as granite, while beneath the ice is an ocean hundreds of kilometers deep that remains warm due to Interaction of the gas giant's magnetic field with the moon's metal core.
Living on such a moon would be much more resistant to changes, asteroids, and radiation than living on a planet like Earth.