2 Questions about the Earth?

Question

Is the Earth the only planet with an ocean? And can you name three ways to assess that the Earth is round? I've read like hell to find out the first one and the book doesn't really give an answer to the second one. That one seems to be a common sense question that I must not have the sense to figure out. Maybe I'm thinking too much.

Answer 1

There are other worlds in our own solar system with an ocean, though not necessarily like our own, Jupiter being one of them; it is also believed that there was, at least at one time, water on Mars.

As for the Earth being round, I would say the fact that it has been viewed from orbit and the moon would be good evidence.

I will also put forth the historic fact that ships have been sailing around it for nearly five hundred years as proof.

I will finish by saying that the time zones are also evidence that the Earth is round. If it were flat, we would only have one time zone. It is the curvature of the Earth's surface, as well as its rotation, that gives the illusion of the sun rising and setting. I hope this helps.

Answer 2

Depends on the definition of ocean. Jupiter has a liquid surface, so the whole planet is an ocean technically (though it isn't water).

Observation is the only method of assessing that the Earth is round that I know of. Past that you can have observation from space, observation from a high flying aircraft, obervation based on angles to objects (the sun for example), etc.

Answer 3

An additional way to determine that the earth is round is the shape of its shadow as the moon goes into it during an eclipse of the moon - curved edge.

Answer 4

Earth is Earth ,ear and hear.