Milky Way likely has more planets than stars

When the AI enhanced remnant that had once been fictional astronaut David Bowman in Arthur C Clarke’s 2001: A Space Odyssey looked into the monolith, he said “My God, it’s full of Stars!” A sharper-eyed super-being might have mentioned the many more planets our home galaxy has been tightly hiding away these many megayears.

Thanks to the Kepler mission, astronomers now estimate there are at least one or more planets for every star in the Milky Way. And just today Kepler reported back it has found a brother and sister for the double start circling planet nicknamed Tattooine from Star Wars announced last year. Click on the image at the top of the post to learn more about Kepler’s 34 and 35!


  1. sumdum says

    More planets than stars ? That sounds so bizarre. Is it ? I mean, I have no idea about what is and is not weird in the universe, but this sounds really odd to me.

  2. fredbloggs says

    It would be surprising if it were not otherwise. Stars form from nebulae. A load of crap is left over after star formation. That crap forms planets. I think it would be rare to find stars that DIDN’T have planets, so that there are more planets than stars seems obvious.

  3. scenario says

    There are many more little stars than big stars. In our solar system there are a lot more asteroids than planets. It only makes sense that planets will outnumber stars.

  4. Trebuchet says

    This is cool, and makes sense at the same time. The only star system we can study in detail, our own, has at least eight planets and many thousands of other orbiting objects. It’s a pretty common type of star, formed in what is no doubt the usual way, so there’s no reason to expect other stars to be wildly different. We don’t have the technology, yet, to really look at earthlike exoplanets but its getting better every day. Science rules!

  5. The Lorax says

    Considering our own system, which yes, has a lot of planets, but more importantly has a metric shit-ton of asteroids, comets, and assorted space-junk, I would imagine that most stellar systems have equivalent junk, and it would thus stand to reason, planets. There are probably many rocks just floating aimlessly through space, lost from their parent star during the formation of their brothers and sisters.

    Life on other planets? Yes. It’s not a question of if, it’s a question of when.

  6. jerthebarbarian says

    The reason why this is interesting is because previously there was an assumption that very small stars like Red Dwarfs and smaller would not necessarily have planets. Because the assumption was that most planets would be gas giants like Jupiter, Saturn and so on and the small stars wouldn’t have the mass to hold onto massive bodies like that.

    The new estimates suggest that a lot more planets are going to be rocky bodies rather than gas giants – which means that it’s far more likely that small stars can hold onto them and have planetary systems – to the point where EVERY star is likely to have more than one planet attached to it. Since a large percentage of stars are the small ones, that means it’s much more likely that there are a ton of planets out there.

    Phil Plaitt has a little bit of this and some links to more information on the Bad Astronomy blog.

  7. henrikbn says

    Another reason that it is surprising, is that most stars are thought to form in groups. As double stars or more (sometimes in large clusters of thousands of stars or even more). In such an environment, planet forming is traditionally thought to be unlikely because of the chaotic dynamics. And if planets formed, it is unlikely that they would survive for long. It is simply too unstable.
    This wisdom seems to be challenged by observation now. Does anyone know if planets have been found in multple star systems?

Leave a Reply