With admiration and kudos to "Labouts" for his superb previous answer to the
same question, we reproduce it below. If you haven't the patience to read it,
the loss is all yours. In summary, the answer to your question is "Lots".
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Astronomers estimate there are 1021 stars in the universe. With a conservative estimate of three planets per star (some could have many more, some would have none at all) this puts the estimated number of planets into millions of billions.
The actual number of planets in the universe is difficult to ascertain. However, we do know that the number is very, very large, and the true figure is completely beyond human comprehension.
No offence to the person who wrote this, but this doesn't make any sence.
The number of known planets changes by the day. So far, we've confirmed the existence of the 8 main planets of the solar system, a handful of dwarf planets (including Ceres, Pluto, Sedna, Eris, and a few others), and 429 extra-solar planets in the nearby portion of our own galaxy. Estimates on the number of planets in the universe are based on the observed distribution of these relatively few known planets.
It's unknown just how many planets exist in the Universe. The number is likely huge - trillions upon trillions!
On average half the stars might have planets, assuming around 10 planets per star (so an average of 5 planets for each star) around 500 billion, billion planets.
According to current research, it seems likely that each star (or at least most stars) has at least one planet.
Outside the solar system some have been discovered orbiting other stars. It is suspected that most stars possess planets because of a thing called angular momentum.
In the solar system most of the angular momentum is contained in the planets, which means that if the planets were collapsed into the Sun it would rotate on its axis about 50 times faster, which might cause it to fly apart. It's the same effect as when a ballerina is rotating, and when she pulls her arms in she rotates faster because of the angular momentum of her arms and hands.
The Sun is a very average star in many ways and the total angular momentum of the solar system is probably typical, so when we see other stars sitting there without flying apart, it's a good bet that they possess their own solar systems. But we can detect only the very biggest of the planets going round other stars.
There are 8 planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
There are eight confirmed planets in our solar system, orbiting around the Sun. The Milky Way galaxy contains billions of stars and is estimated to have billions of planets, but the exact number is still unknown.
The world is a planet; planets are not in the world. Your question is not clear.
There are many other planets in many other galaxies.
1...Earth
There are four gaseous planets.
There are eight planets.
there is many
700 quintillion planets There are over 700 quintillion planets in the universe — but there's no place like home.
the whole solar system
All the planets like the whole Solar system. But the sun is going to be really big!
the whole world should but not the whole world does
about 300,000,000,000-400,000,000,000 pyramids in the whole world
there has been 3,420 floods in the whole world
The "world" constitutes the planet Earth. There are 8 major planets around the Sun in our solar system, and many more orbiting other stars. (see related question)
There may be planets orbiting stars in the constellation Gemini, but planets do not orbit whole constellations.
There are 1,000,500 Brookyn's in the whole WORLD!
There are two billion in the whole world.