But as of today, Kepler has found over 11,000 stars with at least one planetary candidate, and over 18,000 potential planets around those stars, with periods ranging from 12 hours up to 525 days. In other words, there are:
1. a huge variety of planetary systems out there, most of which are very different from our own,
2. orbiting a wide variety of stars, including binary and trinary systems,
3. and we are only seeing the ones that are large enough, orbiting their stars close enough, that also have unlikely, fortuitous alignments with respect to our line-of-sight.
You may have read this week that there are at least 100-to-200 billion planets in our Milky Way, and that’s true, but that’s not an estimate; that’s a lower limit. If you instead were to make an estimate, you’d get a number that’s at least one (and more like two, if you’re willing to make inferences about outer planets) orders of magnitude higher: closer to ten trillion planets in our galaxy, alone!
This doesn’t even include orphan planets (without a parent star), which we know exist, even if we don’t know their numbers yet. Over time, we’ll continue to learn more and refine our estimates, but right now, there are at least about as many planets as there are stars in our galaxy, and quite possibly many, many more than even eight times that number.
Our solar system may turn out to be average, slightly above average, or somewhat below average; we’re still not sure. But regardless of which way it goes, we’re talking about trillions of planets in our galaxy alone. And remember, our galaxy isn’t alone in the Universe.
With at least 200 billion galaxies out there (and possibly even more), we’re very likely talking about a Universe filled with around 1024 planets, or, for those of you who like it written out, around 1,000,000,000,000,000,000,000,000 planets in our observable Universe.
How Many Planets Are In The Universe? – Starts With A Bang
What a great time be alive. Even though we'll probably never find out much about these planets.
What if we all got our own galaxy after we die.
1. a huge variety of planetary systems out there, most of which are very different from our own,
2. orbiting a wide variety of stars, including binary and trinary systems,
3. and we are only seeing the ones that are large enough, orbiting their stars close enough, that also have unlikely, fortuitous alignments with respect to our line-of-sight.
You may have read this week that there are at least 100-to-200 billion planets in our Milky Way, and that’s true, but that’s not an estimate; that’s a lower limit. If you instead were to make an estimate, you’d get a number that’s at least one (and more like two, if you’re willing to make inferences about outer planets) orders of magnitude higher: closer to ten trillion planets in our galaxy, alone!
This doesn’t even include orphan planets (without a parent star), which we know exist, even if we don’t know their numbers yet. Over time, we’ll continue to learn more and refine our estimates, but right now, there are at least about as many planets as there are stars in our galaxy, and quite possibly many, many more than even eight times that number.
Our solar system may turn out to be average, slightly above average, or somewhat below average; we’re still not sure. But regardless of which way it goes, we’re talking about trillions of planets in our galaxy alone. And remember, our galaxy isn’t alone in the Universe.
With at least 200 billion galaxies out there (and possibly even more), we’re very likely talking about a Universe filled with around 1024 planets, or, for those of you who like it written out, around 1,000,000,000,000,000,000,000,000 planets in our observable Universe.
How Many Planets Are In The Universe? – Starts With A Bang
What a great time be alive. Even though we'll probably never find out much about these planets. What if we all got our own galaxy after we die.
to me is all that matter and space was at one time in an infinitely small point. 
