Today it is not possible to determine whether life is possible on the new planet, partly because it orbits a red dwarf type star, something that could pose difficulties for the development of life. On the other hand, in a recently published article, Yosef Gil and Amri Vandel from the Hebrew University show that The aforementioned difficulties do not necessarily constitute an obstacle to the development of life
It's been weeks Rumors are flying around About discovering a world with the potential for life orbiting the closest star to our sun, Proxima Centauri. It is actually a small red sun (red dwarf) that is about 4 light years away from us. Yesterday (24.8) the official article reporting on the fascinating discovery was published in the prestigious journal Nature. See also the scientist 25.8: "A terrestrial planet has been discovered around Proxima Centauri, the closest star to the Solar System".
This discovery does not come as a surprise to astronomers who study planets outside the solar system, who are familiar with the discoveries of planets in recent years, mainly by the "Kepler" space telescope. Two years ago, Omri Vandel from the Hebrew University published a study based on Kepler observations, which estimates that the nearest planet to us May be found at a distance of about 10 light years.
The current discovery is based on observations made this year for 54 nights with the help of the 3.6 m diameter telescope and the HARPS system of the European Space Agency in Chile and additional observations from 2000-2014. These observations confirmed the existence of a planet with a mass of 1-3 times the mass of Earth, orbiting Proxima Centauri in a period of 11.2 days. It follows from this that the new planet, called Proxima Centauri b, is about 7.5 million km from its sun, which places it within the "Habitable Zone" that allows liquid water to exist on its surface (it is important to note that the existence of water liquids depends not only on the distance from the sun but also on the atmosphere of the planet).
Naturally, the discovery caused a wave of rumors and discussions regarding the possibility of life on the surface of the new planet. "A sedentary, rocky planet around Proxima Centauri would be the most natural location for an alternate location for our civilization after the Sun dies, in about five billion years," says Avi Leib of the Harvard-Smithsonian Center for Astrophysics and advisor to the groundbreaking Starshot project, announced in April of this year and offering to send tiny spacecraft that will move at about one fifth of the speed of light to the Alpha Centauri system.
See also a full interview with Prof. Leib published at the same time as this article:The Israeli astrophysicist's journey to Proxima Centauri"
But what are the chances that the neighboring planet does have life?
As exciting as it is, the new discovery does not allow astronomers to know whether Proxima Centauri b is a good host for life as we know it. For now, scientists don't know enough about the planet to estimate conditions on its surface. As mentioned, these conditions depend, among other things, on the type of its atmosphere. But even based on the data known today, it is unlikely that this is a twin to Earth. The main reason for this is the sun of the new planet - a red dwarf type star, whose properties are very different from the properties of our sun.
"The planet itself is in the habitable zone, but that does not mean that it will return, that it has life conditions as we know it on Earth," says Anglada-Escudé, the lead author of the discovery article. "This question requires a lot of work."
As mentioned Proxima Centauri is a red dwarf. This means that it is much dimmer than the Sun and emits most of its light in the infrared range. Its mass is about 12 percent of the mass of the Sun, and it has a magnetic field 600 times stronger than the Sun. In addition, it emits X-ray radiation, about the same amount as the Sun, but due to its proximity to its Sun, Proxima Centauri b absorbs an X-ray radiation flux 400 times higher than that of the Earth. Also, early in their lives, red dwarfs have strong bursts of UV radiation. In other words, red dwarf planets, close enough to be in the habitable zone, i.e. having a temperature that allows liquid water, may be exposed to high intensities of life-threatening energetic radiation.
The German astronomer Arti Hatzes listed these problems in an article also published in the journal Nature. The eruptions and X-ray radiation may erode or change the composition of the atmosphere, leaving the surface unprotected against deadly radiation, but this does not rule out the existence of life. "If the atmosphere is thin, more UV radiation will hit the ground," says Lisa Kaltenegger of Cornell University. "Life on the surface of the planet will have to take shelter underground or underwater, or rely on some other mechanism to protect themselves from the radiation."
Another potential problem for sustaining life is that planets very close to their sun like Proxima Centauri b tend to be "tidally locked", that is, always face the same side to the sun. The side facing the sun will be very hot and the other side - very cold.
"Life in Proxima Centauri b, if it does exist, probably had a more difficult start than life on Earth," Kaltenegger said. "But that's exactly why it's so exciting to explore these other worlds. They are just a little different, and therefore may reveal an incredible variety of life forms that we can't even imagine."
In an article published a few months ago in the International Journal of Astrobiology (see also in "Hidan") Yosef Gil and Amri Vandel from the Hebrew University of Jerusalem showed, because there is no obstacle to the development of life similar to that which developed on Earth on planets surrounding red dwarfs, contrary to what was commonly thought until a few years ago. In particular, Gil and Wendel show that such planets have suitable conditions for photosynthesis, which is considered essential for the existence of most forms of life on Earth.
In conclusion, despite the fact that Proxima Centauri b is a very different world from Earth, life may have developed on it, and perhaps even life that is not very different from that on Earth.
The Israeli partner in the discovery - Dr. Aviv Ofir from the Weizmann Institute
Editor's note - The following paragraph is based on a Weizmann Institute press release:
Dr. Aviv Ofir, from Prof. Oded Aharonson's research group in the Department of Earth and Planetary Sciences at the Weizmann Institute of Science, is a partner in the international research team.
Proxima Centauri is a "red dwarf" star. Its diameter is about one-seventh the diameter of the Sun, and its brightness is much smaller than its brightness (the sunlight is almost 600 times stronger than its brightness). Measurements made by the scientists showed that a small planet revolves around Proxima Centauri, whose mass is at least 1.3 times the mass of the Earth, and it orbits its sun every 11.2 days. This planet was named Proxima Centauri b.
The discovered planet moves in an orbit very close to its sun (only about 5% of the distance between the Earth and the sun), but since its sun is so pale, the temperature on the surface of Proxima Centauri b apparently allows the existence of liquid water on -His face. Dr. Ophir says that, despite this possibility, at this stage we have no ability to determine whether the conditions on the surface of the planet are suitable for life as we know it.
The planet was discovered using a method called "radial velocity", in which the speed of the sun is measured (using the Doppler phenomenon) with great precision - about one meter per second (about 4 km/h). In fact, the expression "a planet moving around its sun" is not accurate, since in fact, the planet and the sun both move around their common center of gravity (which is naturally close to the center of the sun). When the scientists notice that the sun (the star) accelerates its movement towards us, cyclically, they conclude that there is another body in the system that pulls the sun back and forth. In the case of Proxima Centauri b, this additional body turns out to be a low-mass planet.
The discovery of a planet orbiting Proxima Centauri (undetected by many studies carried out in the previous 100 years) was possible because the new observations were specially designed to be highly sensitive to this type of planet, which previous measurements had hinted at.
Dr. Ofir, who participated in the establishment of the research team, and in other studies designed to definitely identify a planet moving around Proxima Centauri, adds that it is actually not possible to see Proxima Centauri from Israel, since it is a very southern planet, which is below Israel's horizon line all year round.
11 תגובות
Exploring the moon Europa is better and better than exploring Kantori.
Proxima b, the newly discovered planet - relax! According to Stephen Hawking; We have about a thousand years to live until the greenhouse gases run out on us. And his research has no God to help. And on earth the countries are busy with fratricidal wars and live today and die tomorrow. And Khomeini (a Persian religious fanatic who rules and is mentally ignorant) threatens to destroy Israel with atomic bombs, and Israel will return fire,,,,, and everything will ignite into a world war! So we will miss the greenhouse gases on the way and the remaining thousand years.
Regarding conditions for sustaining life.
The question arises whether to base it on findings or on logical possibilities.
If we base ourselves on findings, we can only relate to lives similar to our own. They are based on the chemistry of the carbon compounds, and need water and energy differences in their environment. Therefore we can say that any environment that has carbon, liquid water and energy differences - life can exist in it. (and energy differences are everywhere).
If we base it on logical plans - here you can already run wild. Let's start by narrowing down the requirements. Why only water and not any other means of transport such as liquids or plasma? Why only carbon and not silicon and others? Any energy differences are enough for us to live.
So at the time I had an idea that seemed wild at first. Why shouldn't there be life in the sun and other stars?! Energy differences - there are. Means of transport - Yes. So it would be life based on nuclear reactions. They may be thinking so fast that they will never be able to communicate with us. Or vice versa: so slowly that even then they won't be able to communicate with us.
If our goal (the human race) is to exchange information with other civilizations - we will look for life according to approach B. And if our goal is to settle, we will adopt approach A.
a life that.,
You present a theory called rare earth theory, which in fact its failure in my opinion is that it uses the only case we know of the development of life and claims in fact that this is the only way complex life can exist.
Actually, in the habitable zone of the solar system, there are 7 planets and moons. Of these, only 1 of them developed life (as far as we understand). This is a statistic not seen at all. In fact, we still do not know if there is life on Mars or if there was no life - according to a study published by NASA in March of this year, methane emissions on Mars are irregular and difficult to explain by a geological source. Maybe it's bacteria - maybe the remains of bacteria. Which means that Earth may very well not be the only planet in the solar system that has life on it.
In addition to that, the most suitable object for life - probably - after the Earth, is not a planet at all and is not in the habitable zone of our Sun - it is of course Europe. I am convinced that if there is an ocean there at a temperature favorable for organic chemistry (that is, above 0 degrees Celsius and below 60 degrees), then there is life there.
In any case, in my opinion there should also be life on Nega - it is simply too strange a planet - it does not rotate almost, does not contain a magnetic field - in my opinion I would focus much more on the study of Nega to understand how it happens that a planet is so similar to Earth (much more from Mars) which is in the habitable zone of the solar system, is so different.
In any case, I don't think there is an intelligent technological civilization on Proxima B, because we would have already found signs of this. What's more, we still don't even know how rare life is - certainly how rare intelligent life is.
Chaim P.
I agree with you. I would be even more extreme, and claim that water is not a necessity either. There is no reason to discard other liquids. or even a gas that will be used as a basis for dissolving various chemicals.
to cheers
You have exaggerated your demands.
What is the requirement for sustaining life? Scientists tend to answer: water. point. end. (The water also defines a range of temperatures. Their presence also indicates a suitable chemical environment)
There is life at the bottom of the ocean on Earth. These do not need the sun, moon or seasons. They may be the ones who preserved life on Earth during the ice ages. They exist from the inner heat of KDA!
I actually reject all the requirements A-F that you presented.
I think these scientists are either crazy or looking for headlines. The chance that life will exist there does not aim for 0- but exactly -0-. It is a small red dwarf that is actually similar to our Sun at its twilight, with a large magnetic field. Around it revolves a tiny sphere slightly larger than the Earth, which makes a revolution for about 12 days. There are no seasons, there is no moon that stabilizes the rotation and it probably has no magnetic field either. Its temp is probably in the range where there can be water on it. no more. The biological complexity is so great that the statistical chance that there is any Earth-like life in the cosmos, something previously thought does not reach 3 possibilities and I am saying about the entire cosmos and not our galaxy where the statistical chance of life existing is still -0-.
Therefore, it is not for nothing that no biological marker is found either on Mars or on any planet in the immediate vicinity. Also the chance of finding a biological entity in our galaxy is still -0-. The reason is simple. The complexity of such a large biological entity that includes: a. A super nova explosion. B. A gathering of mass in the form of a sun and around stars with a precise composition of the material ratio of oxygen, nitrogen, carbon, chlorine, sodium, water, and everything else. third. A ball of mass that will hit the earth and move it by about 37 degrees, in order to create the seasons. d. May he have a moon to stabilize the rotation angle. God. to rotate at the correct speed. and. It will be located at the edge of the galaxy so that it will not be disturbed by damage from the masses running around. And a million more reasons.
Please stop getting excited. This is an interesting scientific discovery and nothing else.
Reinforces Danny's words.
There is a lack of data regarding the new star and according to the situation in our solar system, most likely it is a lifeless star
And exactly in the area of the equator, A. Benner will live and there will be camels, in the north, and bears, in the south. And so they will live.
If Proxima Centauri b is gravitationally locked to its sun, then on its hot side, the one facing the sun, camels will live, while on its cold side, the one hidden from the sun, polar bears will live.
Proportion is needed, both Mars and Venus are planets that theoretically allow life, and this is much clearer to us because they are not just a point blocking some light on a distant sun 4 light years away. But really close to us.
So what exactly have we discovered there so far?
Calm down your exaggeration with the media publications.