Astronomy/Science question.?

Question

"Explain why observation of the size of the moon for a year would suggest that the moon is a small body revolving around the earth rather than another planet around the sun - ignoring moon phases and focusing on the changes in the radius of the circular part you see."

I need help and science is not my area of expertise. Thanks in advance.

Answer 1

Well it sets and rises so that's our clue that it's not part of the Earth. Then we would notice that it's appearent radius does not change dramatically. Another planet would appear to grow larger as it's orbit brought it closer to us and smaller as it drew away (or we drew away). A planet in another orbit would not move along with us because the farther out from the sun you are, the longer it takes for you to move around it (complete your orbit), fairly uniformly.

Answer 2

Good question!

Here are some things for you to consider:

1. The Moon is going around the Sun. It is in a partnership with the Earth. They are both going around the Sun together.

2. The Moon is called the Moon because in ancient times that was how they defined one month: the time the Moon took to reach the same position in the sky as when you started counting.

3. Since the Earth only takes 24 hours to rotate one time, it is easy to watch the Moon and see that at times it is on the far side of the Earth, and sometimes closer to the Sun than the Earth. Then it repeats the path again, once each month.

4. The ancients watched the sky. It was important to them. They named the patterns of the stars - the Constellations. But they saw that some of the stars wandered in strange paths. They named these stars 'Wanderers.' Or in their language, 'Planets."

5. If you were on another planet and did that, the Earth and the Moon would both be called planets. Probably 'The dancing twins.' Maybe 'I gemelli ballanti!'

;-D Astronomy is a blast!

Answer 3

iMi has it right. The other two are telling you correct information, but it's info that doesn't answer your question.

If the Moon orbited Venus, say, then as Earth and Venus got closer, the Moon would appear larger in the sky. As Earth and Venus got farther away, the Moon would appear smaller in the sky.

Venus *does* appear to get larger and smaller, but you can really only see the change through a telescope, over the course of weeks or months.

The planets all orbit the Sun at different speeds and different distances, so the actual distance between any planet and Earth is always changing. Imagine two cars in a traffic circle, in different lanes, going different speeds. Sometimes they will be right next to each other, sometimes they will be across the circle from each other.

Answer 4

Well even Ptolem thought the moon revolved around the earth. Tycho did think the Moon revolved around the sun along with Venus, and Mercury but then thought that the Sun revolved around us. The answer above is a great answer