on planet earth
Cosmology is the study of the universe as a whole (as compared to our particular corner of the universe, the planet Earth, which we naturally have studied very closely). Cosmology is concerned with such questions as, how was the universe created and what is its past history, how big is it, what does it contain, how does it evolve, what will it be like in the future.
Besides Earth? Saturn.
If it's any planet other than Earth, always capitalize it. If you're talking about the planet Earth in an astronomical context, or in any other context where you feel a need to clarify you are specifically talking about Earth and not some other planet, capitalize it. For example: "Temperatures on Earth range from -89°C to 57°C." If you're using the word 'earth' in more of a casual, day-to-day sense, don't capitalize it. For example: "The tree branch broke off in the wind and fell to the earth with a thud."
Time on Earth began approximately 4.5 billion years ago, with the formation of the planet.
Earth does.
The earth has very unique weather when compared to other planets. It is the only planet that experiences the four different seasons due to the planetÕs tilt. The planet earth is the only planet to experience temperate climates.
It takes one year to complete one revolution around the sun. This is the definition of a year. All planets take one (local) year to do so. Years are of different lengths of time depending on what planet you are referring to. A year on earth is different from a year on a different planet
Not compared to earth!
The tilt of the earth causes different day lengths.
In size and mass it is enormous compared to it's parent planet - The Earth.
Long before. By the ancient Greeks, who compared the lengths of shadows of a stick at different latitudes on the same date.
It is about three times larger than planet Earth.
It is about three times larger than planet Earth.
0.2408 of an Earth year.
Venus is often compared as Earth's "sister planet", being similar in size and internal composition.
Rotation for a planet means spinning, and one complete rotation is a day (on that planet). All of the planets have different spin velocity, and therefore different day lengths. The shortest is Jupiter at under 10 Earth hours, and the longest is Venus (which rotates "backward" or clockwise) taking 243 Earth days.