No, it isn't. There are hundreds of millions of stars in our galaxy nearly identical to the Sun, and at least millions of billions in all the stars in all the galaxies in the Observable Universe.

That doesn't mean that any significant number of those stars have planetary systems exactly like ours. The planets formed from random collisions, and some of the later collisions and interactions with the smaller debris left over from their formation significantly affected their sizes, orbital sizes and compositions and physical features. Still, with millions of billions of stars like the Sun, it is quite possible that there are a few planetary systems sufficiently similar to ours that they would be considered essentially identical in terms of their gross properties. Still, if you want to take into account geological activity, specific patterns and timings of bombardment by other objects, and the development of various lifeforms, then if you insist on going into specific details, every planetary system is probably at least a little different than every other one.

Off-hand, I'd guess that so-called "M" systems are not nearly as common as in science fiction fare like Star Trek; but I'm sure there are plenty of them. But as to whether an M type planet would have an atmosphere and biosphere that wasn't so alien that it would be fatal to human life, that's another matter entirely. So to a certain extent I'd agree with the idea that in at least some ways our planetary system is unique; but as to its general structure, and the nature of the Sun, your proposal is far off the mark.

The truth is that we don't really know. We know that planets are very common, but it is much easier to detect large planets near to their stars. Therefore the systems we've discovered tend towards this pattern: you may have heard of 'hot Jupiters', named because they're big and gaseous (like Jupiter) and close to their stars (so, hot). Until we can reliably detect smaller planets like the terrestrial planets in our solar system we won't know if our system is 'normal' or not.

As for the Sun itself, it's relatively normal in the sense that stars of its mass and composition are very common. It's less normal in the sense that it's not part of a multiple-star system (i.e. a binary, etc.), so if our planetary system turns out to be 'special' that might have something to do with it.

Tangentially, probably one of the more special aspects of our planetary system is actually the galaxy in which it lives. The Milky Way is quite large and of a less common type compared to other galaxies. So again, if we're special in the universe, that might have something to do with it. But that would be much harder to determine because it would require comparison with planetary systems in different galaxies: MUCH harder than comparison with other systems within our galaxy.

At the moment we do not know of an exact analogue of our solar system when compared to the more then 4100 exoplanets discovered so far. But I think this is due to observational bias, with the methods currently employed it would not be easy to find our solar system in the vastness of space. I think we will have to wait, until finally a exoplanetary system is discovered around a G- or K-type star, which has a row of terrestrial planets close to its star and giant gas planets farther out. But I sincerely do NOT think, that our solar system is special on a cosmic scale.

Courtney Seligman ,

Thank you for your contribution to this thread. I have not heard of any solar system with rocky planets in the observable universe.

Anita Petzler ,

I appreciate your thoughtful reply. I agree with you that findings are, so far at least, that other suns have large gaseous satellites. The notion that our sun was once part of a binary star system appears in Stellar Evolution.

Tilmann Althaus ,

I am amazed that with all of the astronomical data you know about, and not any evidence of a solar system similar to ours, you remain so optimistic that this system is not unique!

Nancy Ann Watanabe ,

There have been detections of rocky planets around other stars, here's a paper that found 3 around a single star: Preprint Red Dots: A temperate 1.5 Earth-mass planet in a compact mul...

I think when Tilmann Althaus expresses sincere doubt that we are unique, it comes from a more scientific perspective: if our Solar system is unique, there must be a reason why. So from a scientist's point of view, the idea that the Solar system is unique requires much more evidence than the idea that it isn't unique. Therefore the fact that there probably is an observational bias against Solar-equivalent systems means we still need to keep an open mind and not commit to any conclusions just yet.

Anita Petzler ,

Thank you for the preprint. I agree with you that finding Earth-like planets is in the domain of frontier research and still remains rather speculative. It may well be that stars are comparable to snow flakes, i.e., each star is unique; thus, so, too, each satellitic body in every star system is unique. In this logical line of thinking, Earth is unique. There will never be another Earth; indeed, Earth itself is changing.

Nancy Ann Watanabe For sure! But then we could say 'How unique is unique?' I think what people want to find in order to say that the Solar system isn't unique is a big group of extra-solar systems with a few rocky planets close in and gas-giants farther out. I don't think they'd set the bar much higher, i.e. by saying that the most massive planet should be the first of the gas giants, for instance, or that the innermost rocky planet be the smallest. They definitely wouldn't require that these systems host a rocky planet with surface water, ice-caps and intelligent life. In that respect Earth may be very special, but the universe is too big for me to concede it's unique!

Anita Petzler ,

Thank you for your detailed answer! My impression is that the quest is to find, not so much a solar system that is identical to our own solar system, but, instead, anything that resembles the inner rocky planets, i.e., Mercury, Venus, Earth, and Mars. Even today, scientists are stymied by the presence in our solar system of the giant gaseous wanderers in the outer orbits, i.e., Jupiter, Saturn, Uranus, and Neptune. You may be right that in order to find another Earth, it is important that we better understand our own solar system!

Thanks, Pedro L. Contreras E. , for your recommendation! I appreciate your support! Best regards.

Thank you, Senapathy Marisennayya , for your recommendation! Best wishes.

My pleasure Dear Prof. Nancy Ann Watanabe

NASA DISCOVERS PLANET UNLIKE ANY IN OUR SOLAR SYSTEM ...

https://www.independent.co.uk/

It is just a miracle::: https://www.thesciencefaith.com/solar-system-the-name-of-a-miracle/

I will give two different opinions.

1. Its a Myth. There are billions of solar systems lying around. And I'm pretty sure that you know, our sun is in the category of 'Dwarf Star'. So obviously it's not the only one of its kind. And you can even find thousands or even millions of matches of our planets in the solar system.

2. Its a Reality. You must have the idea of how much luck is needed to be another planet like earth. To be in a sweet spot, the size, the weather, the temperature. You can understand my logic I think.

Thank You :)

D A Gayan Nayanajith ,

Thank you for your contribution to this discussion thread. It was not easy to locate the article; however, I think that the following matches your link:

www://independent.co.uk/life-style/gadgets-and-tech/milky-way-galaxy-stars-discovery-european-southern-observatory-telescope-b672510.html

ASTRONOMERS FIND HUGE, PREVIOUSLY UNKNOWN CLUSTER OF 'SURPRISING' STARS AT THE CENTRE OF OUR GALAXY

Astronomers have found a huge, previously unknown cluster of stars lurking at the centre of our galaxy.

The “ancient stellar population” is made up of a set of stars that the astronomers who found them said were surprising in a variety of ways.

The middle of our Milky Way is relatively full of stars, more full than most other places in the known universe. It is in that region that astronomers found the newly discovered stars.

They appear to have begun as a globular cluster within our galaxy that long ago migrated to the centre of the Milky Way, the astronomers said.

The centre of the Milky Way lies only 25,000 light-years from Earth, in the constellation of Sagittarius. It was only discovered last century and astronomers have been looking to learn more about it ever since.

Much of that research has focused on the extremely massive black hole at the middle of our galaxy. It is surrounded by a one of the densest fields of stars in the known universe, made up of 20 million stars spread across the 26 light-years at the centre.

Read more

• 📷Massive, mysterious stream of gas swirling around the Milky Way finally explained

But those stars are difficult to see, since they are hidden behind an array of dust clouds that block out the visible light, making the area appear dark despite it large population of stars. To peer through, astronomers are forced to use special equipment that capture light at shorter and longer wavelengths.

Astronomers have speculated that other galaxies probably have similar phenomena at their middle, with a central black hole and a cluster of stars around it. But the close distance of the Milky Way means that scientists are able to see with enough detail to spot individual stars.

The researchers did so and explored 700 stars, analysing not only their brightness and colour but also the way they are moving and what they might be made of.

✕

The researchers found that around 7 per cent of the stars had relatively low “metallicity” – or relatively small amounts of heavier elements – suggesting that they are older than the others, and older than expected. What’s more, they appeared to be moving differently to the stars around them, spinning more quickly and on a slightly different plane to the rest of the galaxy.

Simulations indicated that the stars had ended come from elsewhere, either further out in the galaxy or in another neighbouring one entirely. Scientists speculate that the former is most likely, partly because the stars looked more akin to those found in our own galaxy.

The discovery is reported in two papers – ‘On the Origin of a Rotating Metal-Poor Stellar Population in the Milky Way Nuclear Cluster’ and ‘Revealing the Formation of the Milky Way Nuclear Star Cluster via Chemo-Dynamical Modeling’ – both published in Astrophysical Journal Letters today. 

[End of cited online article from the United Kingdom].

Best regards.

Nancy Ann Watanabe

To All:

Here is the article referenced in my preceding post, as follows:

MASSIVE, MYSTERIOUS STREAM OF GAS SWIRLING AROUND THE MILKY WAY FINALLY EXPLAINED

Andrew Griffin@_andrew_griffin

Wednesday 09 September 2020 16:01

Scientists have finally explained a massive, mysterious cloud that is swirling around our galaxy.

Billions of years ago, our Milky Way captured two smaller galaxies, known as the Small and Large Magellanic Clouds. As our galaxy grabbed them, a huge stream of gas called the Magellanic Stream was pulled from them – and now stretches halfway across the night sky, visible with the naked eye.

Astronomers have never been sure how this huge stream was able to form with such a mass. Taken together, it is more than a billion times the mass of the Sun – and there is no explanation of why.

But now researchers have found that a halo of warm gas is wrapped around the Magellanic Clouds, protecting it like a cocoon. That keeps it safe from our galaxy's halo, as well as giving account for most of the mass of the cloud.

When the smaller galaxies moved close to the Milky Way, the halo was stretched out and sown across space, leaving the Magellanic stream.

The researchers detail their findings in a new article, published in Nature, which suggests that previous models of how the stream could form are wrong.

"That's why we came out with a new solution that is excellent at explaining the mass of the stream, which is the most urgent question to solve," adds Elena D'Onghia, a professor of astronomy at UW-Madison who supervised the research.

There is still more work to be done. That includes tests of the proposal: if the cloud formed as the new paper claims, then Hubble Space Telescope should be able to see the corona of gas that surrounds it.

"The stream is a 50-year puzzle," says Andrew Fox, one of the co-authors of the study and an astronomer at the Space Telescope Science Institute, which operates the Hubble Space Telescope. "We never had a good explanation of where it came from. What's really exciting is that we're closing in on an explanation now."

[End of the cited article.]

Best regards,

Nancy Ann Watanabe

Dear all, I think there are multitudes of univers with their own form of structures and forms of life (if any), but I am sure that the uniqueness is in as. May be no other humans exist in other places besides earth. My Regards

I think nature is consistent.

Think of making a cup of coffee.

It takes 60 seconds to come from room temperature to boil.

In this time the blood completes one cycle in the body.

A lecture is 60 min.

The moon completes two cycle around the earth in 60 day.

The earth completes one cycle around the sun in 360 days.

I think all of this is related to one consistent law in nature.

Abdelkader BOUAZIZ ,

I thank you very much for contributing to this discussion thread. Your answer happens to agree with my opinion that our life here on Earth, which is unique among the planets that belong to the cosmos of the solar system, is most probably unique as well in the universe of stars. Nevertheless, many people, including scientists who belong to the community of experts in the scientific community, have published articles in which they suggest the possibility of other planets in distant star systems that closely resemble Earth, and indeed, may possibly be inhabited by humans, or, possibly, may one day be habitable to future generations of present-day humanity. The future possibility that there will exist another planet in the universe of stars contributes to my optimism about the future of humanity because of the fact that our Sun is in the process of evolving from a "middle-age" star belonging to the main sequence category of stars that is developing and headed toward eventually becoming a red giant that will expand and engulf Mercury, Venus, and Earth, before it actually will no longer have any more hydrogen and other gases to burn as the fuel that currently provides it with life-sustaining energy, at which point, evidently, it will shrink, perhaps thereby to become a white dwarf. Although there appears to be no immediate danger, the idea that Earth and the cosmos of our solar system are unique is being viewed by some scientists as "myth," not "reality," based on their knowledge about the inevitable fate (or destiny) of our Sun, which is to expand into a red giant before collapsing into a white dwarf. Best regards, and thanks again!

Abdelkader BOUAZIZ ,

I thank you very much for contributing to this discussion thread. Your answer happens to agree with my opinion that our life here on Earth, which is unique among the planets that belong to the cosmos of the solar system, is most probably unique as well in the universe of stars. Nevertheless, many people, including scientists who belong to the community of experts in the scientific community, have published articles in which they suggest the possibility of other planets in distant star systems that closely resemble Earth, and indeed, may possibly be inhabited by humans, or, possibly, may one day be habitable to future generations of present-day humanity. The future possibility that there will exist another planet in the universe of stars contributes to my optimism about the future of humanity because of the fact that our Sun is in the process of evolving from a "middle-age" star belonging to the main sequence category of stars that is developing and headed toward eventually becoming a red giant that will expand and engulf Mercury, Venus, and Earth, before it actually will no longer have any more hydrogen and other gases to burn as the fuel that currently provides it with life-sustaining energy, at which point, evidently, it will shrink, perhaps thereby to become a white dwarf. Although there appears to be no immediate danger, the idea that Earth and the cosmos of our solar system are unique is being viewed by some scientists as "myth," not "reality," based on their knowledge about the inevitable fate (or destiny) of our Sun, which is to expand into a red giant before collapsing into a white dwarf. Best regards, and thanks again for your answer.

Dear Nancy Ann Watanabe, in my previous answer I avoided to add my personal believe related to my religion Islam. In Islam doctrine de believe about the existance of seven skyes and seven earths, but in this later it is not said if they have inhabitants or any other forms of life or livings. This goes with the suggestion of the possible existance of other forms of life far away in this wide univers.

Another information is that there many tendencies thinking that the core of earth is empty and there exists cities, people and whole civilization. I am sure you have an idea on that Dr. Nancy Ann Watanabe. My Regards

I would think that solar systems, like stars, planets, galaxies, etc., represent basic components of the universe.

Nancy Ann Watanabe RE: The boldfaced claim in "Nevertheless, many people, including scientists who belong to the community of experts in the scientific community, have published articles in which they suggest the possibility of other planets in distant star systems that closely resemble Earth, and indeed, may possibly be inhabited by humans, or, possibly, may one day be habitable to future generations of present-day humanity."

I doubt that any scientist who is in the biological sciences believes that. Humans are a biological species (homo sapiens) that evolved on earth and even if a similar species evolved on another planet they would be a different species, not humans, but perhaps developed enough to qualify for personhood, i.e. for status as nonhuman persons.