Everything humans know about Mars (Part 2)
Read as ‘a few things some people know about Mars’
This is the second part of a two-part series on Mars. You can read the first part here.
Part 1
Part 2 (You are here)
Mars
Mars, the red planet is the second smallest in our solar system (the smallest is Mercury.) Mars is named after the Roman god of war because of its reddish colour. A colour that is caused by the presence of iron oxide on the planet. Humans have known about Mars for a really, really long time. Sightings of the planet date back to as far as the 2nd millennium BCE. That’s like 4000 years ago. The earliest records are attributed to the ancient Egyptian astronomers (yup, that’s a thing) who described the orbital movement of a reddish body in the night sky. The Chinese also have records of the planet dating back to about 1045 BCE. A while later, the ancient Greek’s developed a geocentric model to describe the planet’s motion. You can find the angular diameter of Mars in ancient Greek and even Indian text. Kepler’s work on orbital mechanics yielded more conclusive findings on the behaviour of Mars as a body moving around the sun. It wasn’t until 1610 that man finally got a close look at the planet. The man who had the honour was Galileo Galilei with the help of a telescope. Within the next century, astronomers learnt a lot more about the planet, including its rotational period and axial tilt. With the development of better telescopes, people learnt more and more about the red planet. And there were even times in the 1800s where scientist believed they had detected the spectroscopic signature of water and some people went crazy for a while with the idea of life on Mars. These days, we don’t have to study Mars through telescopes; we can do it through microscopes. The discovery of meteorites(Mars rocks, essentially) originating from Mars has made it possible for us to know what the chemical makeup of the planet might be like. We also have robots (or at least one right now) collecting data on the planet.
Fun diversion: There is a small thought that some scientists have had but don’t take really serious about the presence of Mars rocks on earth. Since these rocks came from Mars to earth, there is an ever so small possibility that they brought what we now know as Earth life to the planet. As I said, that’s not a thing people take seriously. It’s just a thought. By the way, for life to have existed there already, Mars would need to have water, which it doesn’t. Actually, it does, but not really. It’s kind of complicated. We will get to that in a moment.
Deep Dive into Mars
If humans are going to live on Mars, we need to know more than just its colour. In this post, I will be exploring things you should know about what is soon to become a human colony, starting with its surface.
Surface of Mars
Mars has a diameter of about 6779km, roughly half the diameter of Earth. Its total surface area is just a little less than the total land area on Earth (mind you, land area is only 30% of the earth.) Mars is less dense than Earth, with less mass and less volume. By comparison, the Earth’s mass is about 6,000,000,000,000,000,000,000,000 kg (intentionally wrote out all the 23 zeroes) while Mars is 600,000,000,000,000,000,000,000 kg. When you look at it written out like this, it is difficult to tell how much of a difference exist between the two planets but Mars is only about 11% of Earth’s mass and 15% of its volume, resulting in Mars having about 38% of Earth’s surface gravity. The red colour of the planet is caused by the presence of Iron(III) oxide also known as rust. Mars is one big giant rusty ball (for the most part.) The main minerals on Mars are silicon, oxygen, metal and other elements that makeup rocks. It’s a rock in space unlike earth that feels almost like a droplet. Unlike Earth, Mars doesn’t have a global gravitational field which makes it susceptible to solar winds. Scientists believe that Mars used to have a magnetic field just like Earth but something happened that turned it off. In fact, scientists believe that a very long time ago Mars was similar to current day Earth, with a thicker atmosphere and with more water. Humans have the crazy idea that they can return Mars to this glory period but that’s the last part of this post. The theory humans have about Mars not having a magnetic field is that the core was put out by water. So the way things work on earth is that in the core, dense materials sink down to the core while lighter materials rise. This movement of iron through the planet’s centre causes a charge and if you know anything about physics, you know electric charges also cause magnetic charges. Too much hydrogen can shut down the process and some scientists think this is what happened on Mars. However, it is simply speculation and we can’t know for sure what happened. The “Mar’s insight mission” will hopefully give us some insight into that. The soil on Mars has elements like Magnesium, Sodium, Chlorine and potassium which are typically important nutrients for plant growth… Right? No, while plants love nutrients, there is also a lot of percolate in the soil of Mars which is toxic but of course, that’s the least of plant’s problem when it comes to things on Mars trying to kill them. There is no water on Mars… sort of, it’s tricky. The planet has polar caps on top and under the planet just like earth. There is no liquid H2O on the planet because it can’t exist in the planet’s terribly low atmospheric pressure which is less 1% that of Earth. Not to mention that the temperature on Mars ranges between -126 degrees C and 20 degrees C (with 20 degrees being a hot day). There is however a lot of frozen water in the polar caps. If the caps were to be melted, the volume of water recovered would be enough to cover the entire planet in about 11-meter deep water. As a planet that is mostly hills and valleys and rocky terrains, Mars happens to have the solar record for the highest mountain and deepest, longest valley.
Olympus Mons is a volcano on Mars that also happens to be the highest single elevation on any planet in the solar system. It is about 27km high, standing at a height that dwarfs the Everest which is only about 1/3 of that height. This volcano stretches over 370 km. 370 km is a lot of ground to cover. The volcano is believed to still be active but not violently so, only spewing lava peacefully (I stan a volcano with class.)
Apart from the Olympus Mons, Mars has the largest volcanoes in general of any planet in our solar system. Which says a lot about the second smallest planet we have.
On the other end of the spectrum, we have the Valles Mariners which is about 10 km deep and runs for 4000 km. I really can’t say much more about this, that’s just crazy.
Finally, one last thing about the surface of Mars and this is about it shaking — Marsquakes. Just like earthquakes, this is the shaking of the planet’s surface or interior due to a sudden release of energy in the interior. Marsquakes are theoretical (meaning it’s not something we know but something we expect to happen.) Mars doesn’t have tectonic plates like Earth and it is the presence of these tectonic plates that cause quakes on our planet. However, quakes can be caused by volcanic activities and this is what scientist believe might cause quakes on the planet. While there is no substantial knowledge on the matter, there are some really smart people that believe quakes do happen but might be as rare as one every couple millions of years. We will be able to find out more about the seismic activity on Mars from the Insight Mars lander.
Physics of Mars
Let’s talk about some of the important numbers of the planet. We know the mass of the planet already and we know the temperature. Let’s talk a little about some other numbers like the distance of Mars from Earth (which changes.) Because Mars and Earth are constantly on the move, there is no fixed distance between the two planets. When they are closest to each other, the distance between the two planets is about 55 million kilometres and when they are farthest, it is about 400 million kilometres. For humans to be able to launch things from Earth to Mars, they need to have knowledge of not just the distance between the two planets but also something funky known as the synodic period. The synodic period is simply the time it will take for any terrestrial body to return to an observable location in the Earth’s sky. Knowledge of Mar’s synodic period is what we need to know how best to launch a rocket from Earth so we can anticipate its location. Mar’s moves at 86,900 km per hour. The acceleration due to gravity on Mars is roughly 3.7 m/s² meaning humans would weight 1/3 of the weights here, imagine doing high jumps on Mars, that’d be fun.
The atmosphere of Mars
You might have heard people say that Mars doesn’t have an atmosphere which isn’t technically correct. An atmosphere is an envelope of gas surrounding a planet and Mars has that. Mars’ atmosphere is about 95.3% carbon dioxide and 2.7% nitrogen, not a very human-friendly atmosphere. The atmosphere is also very thin, about 1% of Earth’s. In fact, the atmosphere is probably the first thing that would kill a human on Mars, you’d literally fizz to death, like a popped can of coke. Muse over that. There’s also not a lot of oxygen in the atmosphere and humans sort of need oxygen to live so there’s that. Anyway, the sphere that Mars doesn’t have is a magnetosphere (a fancy way of saying it doesn’t have a magnetic field.) It turns out that having a magnetic field is kind of important for a planet. For one, it protects planets from solar winds. Solar winds are charged particles released from the upper atmosphere of the sun. Solar winds don’t have much effect on Earth apart from the Nothern Lights thanks to the fact that we have a magnetosphere. but on Mars, those solar winds directly slam into the planet. I know you might be wondering what bad that could cause but let me just say one word to you: Radiation.
One last thing to know about the Martian atmosphere is whether or not it has clouds. It does but not the type you are accustomed to. There isn’t a lot of water vapour on Mars so the clouds aren’t made of that, instead, they are made of something Mars has a lot of — dust. They have quite a lot of this funky thing known as a dust devil. Mars has a lot of dust which also means it has a lot of dust storms. The dust storms cover entire regions more often than you might expect and sometimes the dust storms occur globally. You read that right. A global dust storm. Where do you run to? Where do you hide?
Statistics of mars
A day in Mars is referred to as a ‘sol’. It is how long it takes for the planet to complete one rotation and it is equivalent to 24 hours and 37 minutes. It takes Mars 687 sols to revolve around the Sun which is known as a sidereal year or just year on Mars.
You know how on earth, we have beautiful red/orange sunsets, on Mars the sunsets are blue. The reason for this is similar to the reason our sky is blue and you can read what I wrote about that here.
Mars’ average distance from the sun is about 227,936,640 km. The planet has two moons namely Phobos and Deimos which were named after the sons of the Greek god of war.
Fun fact about the person that discovered the moons: Asaph Hall. He discovered them both over the course of a week. Hall was literally on the verge of giving up on the search for Mars’ moon but the night that he said ‘it’s all over Jackie’, his wife gave him the type of pep talk only one’s wife can give him. The next day, he found Deimos and six days later discovered Phobos.
Phobos is closer to the planet and rises in the East every 11 hours. Because of how close it is, tidal force of Mars is pulling it closer and in the next 50 million years, it will either crash into the planet or break into a ring around it kind of like what Saturn has.
And on that very bright note of the potential destruction of Mars, we have come to the end of this series. I grossly underestimated how long this post would be so I still have an entire section omitted from this. I will be posting that sometime in the future so you can look forward to that.
In the meantime, thank you for reading all the way to the end. I know it’s hard work
Plug (cool stuff on the internet)
This week on the internet, I think you should check out this news newsletter a couple of my friends make. It’s called “That New News” and yup, it’s a newsletter about the news, it’s great. You can subscribe here or check out their newest issue. They also started a news podcast and you can subscribe to that on Spotify, Apple podcasts or Soundcloud. Or just follow them.
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