How Do We Get to Mars?

This is the kind of question, “How do we get to Mars?” that normally would take a lot of discussion and involve a whole lot of mathematics.

I’m going to try to explain it simply and to the best of my limited ability.

Mars is in orbit around the sun. Earth is in orbit around the sun. Earth, being closer to the sun, orbits faster. Mars orbits more slowly. So you have to wait until the two planets are lined up to launch, which happens about every 2 years or so. But it’s not a straight shot out to Mars. Everything works following the rules of orbital mechanics.

Essentially, we launch a spacecraft from Earth into a highly elliptical orbit around Earth. This orbit is so elliptical, that it extends all the way out to the orbit of Mars. You time it so just as this spacecraft reaches it’s farthest point from Earth before beginning it’s return journey, Mars comes along in it’s orbit. The spacecraft meets up with Mars.

Transferring of orbit. A Martian bound spacecraft launches from Earth in an Elliptical orbit, catching up to Mars at the moment when Mars goes by in it’s own orbit around the sun.

The image above from the Jet Propulsion Laboratory website of NASA illustrates how this transfer of an elliptical orbit from Earth catches up to Mars. This process takes about 9 months for a spacecraft like this to reach Mars, and can be accomplished only about once every 2 years.

How often do all of the planets repeat their exact positions? For example, how often would the planets be just as they were on any given date/time, like a birthday or historic event?

by Wayne Boyd Studied Physics (college major) & Psychology (college major) at St. Mary’s University, San Antonio, TX

You see, each planet orbits the sun at different speeds. Those planets orbiting closest to the sun, like Mercury and Venus, orbit faster. Further out from Earth, Mars takes about 2 years to orbit the sun. Further out, Jupiter, Saturn, Uranus and Neptune all take progressively longer. Then the sun itself is orbiting the galactic center once every 250 million years, and the Milky Way galaxy is moving toward the Andromeda Galaxy at about 67 miles per second. So no planet will ever be in the exact position it was before, ever. The first image shows the planets orbiting the sun in relationship to our own solar system. The second image shows the planets orbiting our sun in relationship to the sun orbiting the galactic center of the Milky Way Galaxy.

How far and how big are the stars from the Earth?

We are in a galaxy with a lot of stars. It is estimated to contain 100–400 billion stars, The nearest galaxy to ours is Andromeda, but the stars within our galaxy, the Milky Way, are from about 4 light years away to about 100,000 light years away. We can see the Milky Way with the naked eye, and it looks, to the naked eye, like a light smear of milk across the night sky. You can’t see the individual stars that are far away, even within our own galaxy. In the Milky Way galaxy there are, as I said, many stars, but in our night sky we can only see about 9,096 individual stars.

Why aren’t humans drilling into the center of the Earth?

by Wayne Boyd

I’m a hypothetical billionaire, so let’s discuss financing this project and the chances of success, what we’ll need to get it done, and so forth. Theoretically, it would seem possible.

At the south pole the earth is 12,715 and a half miles in diameter, or about 7900 miles to the center, but at the equator the diameter is 12,756.32 kilometers or 7,926.41 miles to the center. The earth is thicker at the equator and it would take a deeper hole to drill from there. We can make a drill 12.7 miles shorter if we drill from Antarctica. So let’s start drilling there.

From Antarctica, our drill will need to be 3,950.5 miles long to reach the center of the Earth. That’s 300 miles longer than the distance between New York and Paris.

To build a drill like that we’ll have to use a modular design. We’ll start with a shorter drill bit and keep making it longer as we drill deeper until it reaches 3,950.5 miles long.

The drill would need to be really thick and made of some really strong stuff to get through granite and just generally tough layers of rock. A drill tip with diamond heads is probably the way to go. As we drill down, the bit will get dull from time to time and we’ll have to pull the whole drill bit out to replace the head. That might have to be done several times a day.

Can you imagine being 2,000 miles deep at some point and have to pull the whole bit out to replace the head? Sounds like a logistic problem that might slow us down.

Eventually, at some depth or other, we’re going to encounter molten rock. In the core itself is molten iron. Our drill bit will melt. All that trouble for nothing.

It doesn’t sound practical to drill to the center-most point of the earth by drilling from anywhere.

If I went into space with an open bottle and then sealed it, what would be inside the bottle?

by Wayne Boyd

A lot of space.

In theory, space is nothing, so the bottle will have a vacuum – an empty bottle. In reality, space is not empty, just mostly empty, so the bottle might have a molecule or two, but most likely it will have nothing.

If the first radio signals went into space over a hundred years ago and were received by a populated world how long at 10% speed of light would it take to get a visit or attack?

by Wayne Boyd – Philosopher, blogger, published author

Well, first of all, know that, as you pointed out in your question, we’ve been broadcasting radio signals for about a hundred years or so, which creates a radio bubble around SOL, our sun, with a radius of about 100 light years. So first lets look at how many stars are within that bubble.

According to A stars within 100 light-years

there are about 76 stars of type “A” within that distance, which is not very many compared to the estimated 100 to 400 billion stars thought to be in our own Milky Way Galaxy.

Of those stars, there just aren’t that many candidates for habitable planets in orbit around them.

At present speed and existing technology we could reach the nearest star system proxima centauri in about 10,000 years, which is 4 light years away. We can assume the aliens would have similar problems. If we could go as fast as 4.5% the speed of light, about 140 times faster than any spacecraft we have yet to create, then we could reach our nearest neighbor in about 100 years.

I really don’t think you need to worry. We don’t even know if microscopic alien life exists anywhere other than Earth, and we don’t have any evidence that anything more advanced is anywhere near us in the Milky Way Galaxy. Anyone who wanted to travel hundreds of years to try to invade us would be nuts.

How would life be for us if we were to colonize a super-Earth, assuming the planet is not too far from ours?

by Wayne Boyd – Philosopher, blogger, published author

I don’t know why I’d want to move over to that planet. I’d rather keep working to make things better on this planet. Also, I imagine it might be pretty expensive to move, then I have to buy some land and a house over there, make new friends, and so on. Too much trouble for me.

So to answer your question “How would life be for us if we were to colonize a super-Earth” I would think some people would migrate over there and some people or most people would stay here. I mean, people already have their lives set up here, why move over there?

SSL certificants aren’t free anymore

It’s been a pain and during the pandemic I’ve not been up-keeping with my self-installed, free SSL certificates for my websites, including rationalthinking101.com.

Alas, however, zeroSSL is now charging for SSL certificates if you want more than 3, and after 3 months you don’t get any more freebies.

So I did some research. GoDaddy wants to charge me $80 a year for one SSL certificate if I install it myself. zeroSSL charges $10/month for 3 domains. This means $180/year with Godaddy and $120/year with zeroSSL for 3 domains.

So I went again with zeroSSL.

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.