Earths atmospheric size and composition is unique among all of the planets.
earth
The planet, within our solar system, that has nearly the same diameter as Earth, is Venus.
If the planet is smaller, then it can't have the same size. If you assume that a smaller planet has the same density as Earth (and therefore less mass), its surface gravity will be smaller. If you assume that a smaller planet has the same mass as Earth (and therefore more density), its surface gravity will be greater. This is because we would be closer to the planet's center - or to the planet's matter in general.
field or atmosphere
Is it the planet Mars.
Venus has an atmosphere, though the "air" is not the same as on Earth (and would, in fact, instantly kill you).
no planet
Beacuse earth has water air and Sun the moon has no air or no Sun or water only earth is a life planets the other planets are the same like moon they had no air or Sun and water
Yes earth
earth
No planet is exactly the size of Earth. Venus is close to Earth's size but slightly smaller.
The planet, within our solar system, that has nearly the same diameter as Earth, is Venus.
It depends on what type of air
Because it is the only planet that has air
It doesn't have air for people to live on that planet
Air is retained on Earth due to Earth's gravity.
Venus has almost the same mass as Earth.