How big is the Moon compared to the Sun and Earth?

by Wayne Boyd

This is an interesting question. I’m going to answer it with illustrations.

In answer to “How big is the Moon compared to the Sun and Earth?” I’m going to give you some illustrations that will put all of this into perspective. First, let’s look at a comparison of our Moon with Pluto and other dwarf planets in our solar system. Here’s a picture to illustrate.

So here you can see our Moon is quite large! In fact, it’s so large, it’s bigger than all of the known dwarf planets in our solar system, including Pluto!

Even though the Moon is bigger than Pluto, it’s not big compared to Earth. Here’s the comparison of that.

So the moon is relatively small compared to our big Earth. But when you bring the Sun into the mix, then you have to understand that Earth itself is not very big. In fact, the Sun is so big it dwarfs even Jupiter. Here’s the image of that comparison:

So to sum up, our Moon is big compared to Pluto and other dwarf planets in our solar system, but small compared to Earth. Earth itself is like a pebble of sand compared to the size of our Sun. Fortunately for us, the sun is also a long way away, and therefore looms the same relative size as the Moon in our sky.

I hope that sheds some light on the subject! Thanks for asking a cool question.

Why is the Moon not being pulled into the Earth from gravitational forces? Is the Moons mass stopping gravity from pulling it any further?

The Moon is being pulled toward the Earth, but it’s forward momentum causes it to miss Earth each time it goes around by a wide margin. This is called an orbit.

However, let it be known that because the oceans slosh around on Earth as it rotates about it’s axis (these are called ocean tides), the speed of Earth’s rotation is gradually slowing down. Billions of years ago a day on Earth was only about 8 hours, and now it continues to slow down. We compensate this twice a year by adding leap-seconds as needed.

This slowing of the earth’s rotation causes the moon to drift further away from us every year by about 1.5 inches, so eventually the Moon will escape Earth altogether and drift away.

It will never crash into Earth.

The Universe is a very big thing…

When will the next Super Blood Moon be seen in the U.S.?

So you know what a blood moon is? It’s when the moon moves into the shadow of the earth (a total lunar eclipse), which causes the moon to grow fairly dark and at the same time pretty reddish as the image below shows.

A red moon, sometimes called a blood moon, takes place during a total lunar eclipse when the moon moves into the shadow of the earth and turns red color and quite dark.

Next, do you know what a supermoon is?

The moon has a slightly elliptical orbit around Earth. Sometimes full moons are further away and appear slightly smaller from Earth. Sometimes full moons are slightly closer to us and they appear larger. When the latter happens it’s a super moon.

The moon’s orbit around the earth is elliptical. The closest approach is called the perigee and the farthest point is the apogee. If there’s a full moon during the perigee, the moon appears larger and is called a supermoon.

A super blood moon simply means when the moon is slightly closer to Earth because of it’s elliptical orbit and it passes into the earth’s shadow. The last one was on January 20, 2019, and will be the only one in 2019.

The next total blood moon lunar eclipse won’t be until May 26, 2021, but it will not be visible from the United States or North America. North and South America won’t see a total lunar eclipse again until May 16, 2022. It will not, however, be a super moon at the same time. For that you’ll have to wait about 19 years.

Why have humans never been back to the Moon after 1972?

By Richard Muller, Prof. Physics UC Berkeley, author “Physics for Future Presidents”

There never was much value in going to the Moon in the first place, so there was no good reason to return.

When J.F. Kennedy proposed we go to the moon by the end of the 1960s, his goal was to raise American spirits, to return us to a belief that we could win in a competition with the surging Soviet Union (which was not only beating us in space, but even in the Olympics!).

When Kennedy died, I think we were determined to get to the Moon in the now sacred deadline of the late 1960s, to fulfill Kennedy’s dream.

Scientists liked the Moon shot, primarily (this is my observation, not based on a careful poll) because it injected a lot of money into science in space. If the same money had been made available for science in space, but not involving human transport, then most scientists would have favored unmanned experiments, including unmanned exploration of the Moon. It made much more financial sense, but most people (especially at NASA) believed that without the human involvement, the public would not support high levels of spending.

Once we met Kennedy’s goals, of restoring the US spirit and self confidence, then the financial considerations took over. There simply is not much value added by putting men on the Moon; arguably, there is much science value lost. (Science experiments that have to be man-safe are far more expensive.) On the other hand, you’ll notice that not a lot of money has been spent on sending robots to the Moon. Some, and they’ve done some remarkable things, but not the many billions that go along with a man shot.

Instead, we have spent our resources with unmanned exploration of the solar system, with truly spectacular results. We’ve discovered that every moon of every planet appears to be different from every other moon! (That’s only a slight exaggeration.) The great glory of NASA in the last few decades has been its unmanned program. In comparison, the Space Station has accomplished very little. (Again, that is my personal evaluation.)

What will be the main economic gains of colonies on Mars, or the Moon?

You don’t want me to answer this question. You are looking for a great, positive answer that will make the future look bright not only for colonies on these places, but an economic base for those colonies.

Meanwhile, I’m going to say I don’t think there’s much justification even for people walking on Mars when our robots can do it more safely and less expensively and achieve the same or better results…. what to speak of “colonies.” I think it’s almost laughable and mostly just science fiction dreaming.

People may or may not one day walk on Mars at great risk, and some will probably die in the attempt. There is little reason to go there from a scientific point of view other than to say we did, just like we walked on the moon and then went away.

In the meantime, a safer, cheaper way is send our machines to go.

You see, what this is all about is finding life. What scientists want to do is prove that life can evolve elsewhere than Earth – a so far unproven theory. We want there to be life elsewhere because we want to prove that life was not “created” on Earth alone, but life naturally develops from matter when conditions are ideal.

We don’t need “colonies” or economic bases in space to prove that. We just need to find some germs under some rocks or on some moon around some planet in our solar system. For that we just need space vehicles and robots like the Mars Rovers.

Whether we find life or not is anyone’s guess, but it is still science fiction thinking we will colonize anything off planet.

Why should we focus our “space efforts” on Venus, instead of Mars?

Well, in my opinion we should focus on the Moon.

As for Mars vs. Venus, both have unbreathable atmospheres. Mars is very cold, hundreds of degrees below zero cold. Venus is hot, melt stuff in a few minutes hot.

Mars doesn’t have rain or surface liquid water.

Venus also doesn’t have liquid water on the surface, but it does rain. The problem is it’s raining sulfuric acid.

Any probes we’ve tried sending to Venus have become dysfunctional within minutes.

Why does the moon revolve around the earth?

It just moves forward. The moon isn’t stationary. It has inertia and no atmosphere in space to slow it down. It just goes. As it moves forward, the gravity of Earth tugs on it and it falls, but because it’s moving forward it misses Earth as it falls and goes around, again and again. That’s called an orbit.

Simply said.

Did we “accidentally” bring new bacteria to the moon or Mars via our space exploration programs?

Probably, and that’s why terraforming is a bad idea. Inside the scientifically minded community, there are two distinct ideas.
  1. Don’t contaminate. Leave whatever planet it happens to be in the original pristine condition so we can study it. (This is the predominant, tree hugging concept.)
  2. Screw number 1. Terraform the planet. Make it livable for humans, existing organisms, if they exist at all, be damned.

That being said, we do try all we can not to contaminate planets we send probes to even though some microorganisms may have made it through.

At present, and probably rightly so, NASA does not want to introduce organisms to other planets – or visa versa – introduce to Earth organisms from other planets on Earth. We may have already failed, but we still try.