Mercury's diameter (at the equator) = 48,800,000cmVenus' diameter = 121,040,000cmEarth's diameter = 127,560,000cmMars' diameter = 67,940,000cmJupiter's diameter = 1,429,840,000cmSaturn's diameter = 1,205,340,000cmUranus' diameter = 511,140,000cmNeptune's diameter = 495,320,000cm
all
Half as many as in 1594 centimeters.
The number of planets is not known. The number of stars is not known either, nor if all have planetary systems. Certainly many billions of billions.
All the inner planets in our solar system are all terrestrial planets. They are all small rocky planets with a relatively small atmospheres when compared to the gas giants like Jupiter and Saturn or the ice giants like Neptune and Uranus. This however is not true of other stars. Many stars have large planets very small orbits.
Planets orbit stars, stars orbit a galaxy. Planets are not "on" anything. A lot of stars out there have planets - we are just finding out how many now that we have better techniques to find them. So probably all galaxies have at least some stars with planets.
15cm
Infinitely many.
all of them
All of them
Neptune has only 1 sun, like all planets
No many like Mars have no atmosphere at all.
All of them.
all
All of them
All planets have a core.
Half as many as in 1594 centimeters.
None of the terrestrial planets have "many" moons. Mercury and Venus have none, Earth has one, and Mars has two.