Q: Is there anything unique about our solar system?

Physicist: Maybe.

As far as stars go, ours is a dull as dishwater, middle of the road, dime a dozen, main sequence star.  You can’t spit in space without hitting a Sun-like star.  So this question is really about the stuff around our Sun.  But, beyond their stars, comparing solar systems is a little tricky.

A solar system is basically a star (sometimes a couple of them) with a tiny bit of grit left over.  Not only does our Sun comprise 99.86% of the mass of our solar system, but it’s disproportionately “loud”.  While the Earth may have a smattering of radio antennae pumping signals into space, the Sun is a screaming ball of electromagnetic noise almost a million miles across.  And not for nothing: it’s seriously bright.  So finding stuff around other stars is difficult, not just because everything other than stars is tiny, but because of the stars themselves.  In fact, most of the techniques we have for detecting stuff around other stars involves looking at the effect of said stuff on their host stars.  Ultimately, if you really want to get a good look at other solar systems you’ve got to get off of your podunk planet and go there.

That said, we are now living in the century of planetary discovery.  Every civilization has known about 6 planets: Mercury, Venus, Earth, Mars, Jupiter, and Saturn.  Uranus, Neptune, and Ceres were discovered in the 19th century.  Pluto and the first few exoplanets were discovered in the 20th century.  But in the first decade and a half of this century we’ve discovered dozens of new dwarf planets in our solar system and thousands of exoplanets in other solar systems.  The rate of discovery is ramping up exponentially.

The planets we know about.

The planets that are easiest to detect are massive (vertical axis) and close to their stars (horizontal axis).  We would probably miss most of our planets (blue) if we were looking for them from another solar system.

The methods we use to detect planets around other stars are much better at detecting planets that are big (which isn’t surprising) and close to their stars.  So the easiest planets to find are “hot Jupiters“.  But based on what we’ve seen so far it looks like damn near every star in the sky, even binary and trinary stars, have planets in orbit around them.  Despite the difficulties in finding any planets, we’ve confirmed hundreds of solar systems with multiple planets (which strongly implies that practically all of them have multiple planets).  And that’s based on methods that look at only a tiny fraction of the sky and miss the majority of planets.

The majority of exoplanets have been found by the Kepler telescope. Guess where it's pointing.

In this picture our solar system is in the center and the exoplanets we’ve found are red dots.  The majority of the exoplanets have been found using the Kepler space observatory (guess where it’s pointing).  The point is: we’ve discovered thousands of planets around other stars and we’ve barely scratched the surface.

Even better!  By far the most common element in the universe is hydrogen with oxygen a distant third.  So we can expect to find H2O (water) all over the universe, including on exoplanets, and when we look that’s exactly what we find.  That doesn’t necessarily mean that there’s life out there, but if it’s around it’ll definitely have lots of places to do its living.

So here’s the point.  It’s really hard to see planets around other stars, we miss most of them, and we’ve only looked at a tiny fraction of the nearby stars.  And yet!  We’re finding planets freaking everywhere.  Big, small, hot, cold, rocky, gaseous, short years, long years, dry, or wet.  The shocking variety and preponderance of planets has completely rewritten our ideas about planetary and solar system formation.  We once thought that solar systems would all more or less “follow the same script” during their formation and end up as variations on our own.  Instead we find that each is surprising and unique.  Our solar system is unique like a snowflake in a blizzard is unique.

Some podunk planet.

Some podunk planet.

The top two pictures are from the (free as of writing) exoplanet app and that picture of Earth is from space.

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5 Responses to Q: Is there anything unique about our solar system?

  1. Elvince Ager says:

    The astronomical number of the stars and planets out there is simply mind blowing. I read some time back that the number of stars in the visible universe alone is greater than the number of sand grains in a beach. If that’s so then the number of planets would be wild.
    But getting back on the question at hand. I believe our solar system is unique in one fundamental way. It is the only star system that boasts of having life as far as we know. I understand there are speculations about life in other star systems but until evidence is given this solar system is unique. Given that it took the universe 30% of its entire life to create the first bacteria, I believe life may be too deficcult a feat to accomplish over and over again and getting intelligent life harder still.
    Thus I believe only life makes our star system unique

  2. Bert says:

    To me, our big bang is chock full of life. Trillions and trillions of planets like our earth,
    with different evolutions depending on the atmopheres, gravities,chemicals etc..
    But do other big bangs big bang like our big bang? The day before our big bang,
    a singularity, a ball of somethings. The super gravity had reduced all the matter it
    attracted to be only somethings, the smallest particle that has only mass and gravity.
    Only when they combine with other somethings do other properties develop.
    Is our dark energy somethings?
    Thank you infinity.

  3. Naresh Kumar Pal says:

    I want to know that can we start nuclear fusion or Thermonuclear reaction by using high energy Gamma Rays.

  4. Leo says:

    To develop complex life like on Earth many hundred of million years of stability required. In a system with many planets collisions happen too often which may destroy all complex life. But in fact collision of Earth with a very large planet which killed dinosaurs, did not destroy the whole of life , so maybe its OK..

  5. ENGLISH BOB says:

    HI; It’s funny you should mention that particular solar system. My companions and i , Had decided to take the scenic way home, after a lovely day trip to Orion’s nebula. So, on reading the local tour guide, that had mentioned , that the 4th rock had a very large volcano on it, and as some of the crew needed a comfort break. We decided to kill two birds with one stone. Unfortunately the guide went on to say, that the entire solar system, was subject to a GOD’S ORDER, that’s the. GALACTIC-OBNOXIOUS-DECARBONISATION-SERVICE. It would seems, that a not to bright and very aggressive life form on the 3rd rock. Had just finished, its 2nd global conflict, and had ended up killing over 65 million, of its own species. Apparently over some land dispute, of all things! Anyway to cut a long storey short, the GODS had been talking about upgrading the ape’s to the states of a Virus, so that they could, under the Andromeda Convention, be exterminated ! Personally i think they should. If they ever get off that rock and into spaces, well who knows what damage they could do ? Any way, all the very best, from concerned of M38. cheers!

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