Astronomy: The Sun

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Above is an image of the different layers of the Sun.

Table of Contents

  1. General Facts
  2. Layers of the Sun
  3. Surface Phenomenona
  4. For Educators

General Facts

The Sun is an above average sized star that holds our solar system in place. It is in the top ten percent, in terms of size, of all stars as most stars are red dwarves. A star is a ball of plasma(super-heated gas) that releases energy in the form of heat and light due to the fusion of gases(this is called fusion, it’s when atoms combine to form heavier ones due to the energy in the surroundings). Even though our Sun is 99% of the mass of the solar system, there are stars that are a thousand times larger(the star Betelgeuse is 700 times larger than our sun). The mass of our sun is what holds our solar system in an elliptical orbit, masses exert a force on each other called gravity(insert link to gravity post here). We do not know much about gravity but the link will lead to a post about what we believe happens.

Layers of the Sun

Just like Earth has different layers(Core, Mantle, Crust), the Sun has different layers. The innermost layer of the sun is the core. The pressure in the core of the sun is 260 billion atm(1 atmosphere, or atm, is the air pressure at sea level on Earth) and 15 million Kelvin(at this large scale, 1 Kelvin is approximately 1 Celsius). This is the layer where most of the hydrogen fusion happens, because the pressure(and thus energy) is immense. Every second the sun converts 700 million tons of hydrogen, forming 695 million tons of helium and 5 million tons of energy. To convert it, this is where Einstein’s classic E=mc^2, so 5 million tons of energy is 4,535,923,700kg(5 million tons as kg)*(3*10^8)^2=124,827,108,157,891,338,889 Watt*hours(so this number is the number of joules of energy expended in an hour, and it is gigantic) . For reference, your powerful home lightbulb is 100 Watts, so yes, the Sun produces a crazy amount of energy.

Above the core is the convective layer, this is where all the hydrogen moves up to because it is less dense than helium. This is called convective layer because the temperature gradient between this layer and the core causes the hydrogen to become less dense, float up, cool down, and then sink again.

The circles in the convection zone are the cycle of hydrogen atoms. The image was retrieved from http://burro.case.edu/Academics/Astr221/StarPhys/opacity.html

Above this is the photosphere, which is thin enough for the light to escape. The top layer is the corona, which is thinner than the photosphere but much hotter than it. The corona stretches for many million kilometers. The solar wind is over a million km/hr

Surface Phenomenon

The first important thing to know about the surface of the Sun is that light is emitted from it. This light is what we see. You have heard that it takes 8 minutes for light to be made from the Sun and seen by us. This is only partly true. The distance from the Earth to the Sun is such that it takes 8 minutes for the light to reach us(the speed of light is 3*10^8 meters/second so multiply that by 480 seconds to get the total distance from Earth to Sun). However, the light we see is often more than 100 million years old! This is because of the fact that fusion, where light is produced, occurs in the core. So this light has to escape to the photosphere where it has some potential to escape. While in the core, it will just be circulated for many millions of years until it may escape.

That is how light comes to us, but there are a lot of cool phenomena that happen on the Sun also. These are invoked by the Sun having a significant magnetic field. This magnetic field is induced by a flow of electric charge in the Sun(a current can create a magnetic field, this is Ampere’s law). The flow of charge occurs in the convection zone, because of the high temperatures, not just hydrogen atoms but also free electrons get circulated. Related fact: The earth has a magnetic field for the same reason, but it is because of liquid metals flowing in the outer core that causes a flow of charge. This magnetic field on the sun causes many interesting phenomena on the sun.

Sun Spots

Sunspots are formed when the magnetic field doesn’t allow the plasma to return down the convective layer, causing it to dim on the surface. These sunspots appear in pairs(imagine a North pole and south pole of a magnet, sunspots occur in such a fashion often).
Faculae are the bright rings around the sunspots formed by the concentrated magnetic field. These are very bright due to the heavy magnetic field causing significant circulation.

Solar Flares

A solar flare is when the magnetic field snaps, ejecting material into space. These often occur around sunspots because, as we discussed, the magnetic field around the sunspots is extremely prominent. A solar flare is like a slingshot of solar mass(the components of the Sun) being shot. When you hear of the risk of the Sun eliminating radio communications, flares are the reason

Solar Prominence

A solar prominence is when the sun’s magnetic field pushes the plasma out toward the surface. The difference between a flare and prominence is that a prominence does not eject anything. Rather, a large ring of plasma is formed on the surface of the Sun, directed by the magnetic field.

Coronal Mass Ejections

Coronal mass Ejections(or CMEs) is similar to a flare except its stronger and covers a wider area. These often occur when a solar prominence snaps, because the prominence holds a lot of energy it ejects much more mass. A CME in 1989 caused a total power outage in Quebec. In 2012, another CME occurred but in a different direction, saving the Earth from huge damage. These caused concern because the Earth’s atmosphere protects us from solar emissions, but a CME is so powerful that it gets free electrons through our atmosphere and can cause damage to a lot of our technology.

For Educators

After doing a short presentation about the concepts in the post, I would recommend doing a demonstration on the concept of convection. Check out this you tube video if you need inspiration for how to set one up(or would like to show it yourself). Teaching about the Sun is easiest using diagrams, so I would recommending making diagrams for the different layers of the Sun. Finally, teach about the phenomena by explaining their impact, like the examples I gave in the CME section. This is so students understand that the Sun is more than what we think of it, and that there is a lot to learn about it.

Thank you!

Thank you for reading about the Sun! If you have any comments, let me know at vijaypbharti01@gmail.com or in the comment section below.

Astronomy: The Moon

Before I talk about astronomy, I want to thank you for visiting and ask that if you enjoy what you just read or value our mission here at STEM Enterprises, please support our cause by donating here. Any donation will be used to provide our highly engaging and effective education(check out the website for what all we do) to students deprived of the opportunity to have a meaningful STEM education experience.

Table of Contents

Feel Free to Skip Ahead to Any of These:

Moon Composition

Phases of the Moon

For educators

Welcome to the Moon!

I hope you enjoyed your flight as we reached the Moon. The Moon(notice the capitalization, our moon is capitalized because it is special) is a 3500 kilometer(2200 miles approximately) wide rock floating about 240,000 kilometers from us.

What is the Moon made Of?

You probably have always wondered this, and no, it is not cheese 🙂 Rather, the moon has very large, smooth surfaces called maria(mare singular) which means sea in latin(they truly look like large seas but just black). These are made of basaltic rock, which is the rock that forms from dried lava(just like obsidian from volcanoes). Since it is very glassy, it cooled quickly(more of a fun fact than a major topic, but feel free to read more into rocks to understand how this works). The other part of the moon, the highlands, is also basaltic, but made of slow cooling rocks(as such it is much more bumpy and uneven).

The dark parts are the maria and light parts are the highlands

Phases of the moon

the phases of the moon in a nice diagram

Now that we know what the moon is made of, we should talk about the other important concept of the moon, which is how the phases work. This is diagrammed above but is still very confusing, so do not expect this to come easy. But let’s get started!

The moon cycles through its phases in 30 days(29.5 to be a little more accurate). There are 8 phases total so each phase goes for 3-4 days. Before we talk about them, let’s understand why these phases happen. The half of the moon we say is always the same, this is because the moon is “tidally locked” as its rate of rotation(how long it takes to spin around itself) is equal to the rate of revolution(how long it takes to circle the Earth).

Since we always see the same half, based on where the moon is in reference to the Sun is how much of it we see lit up. The moon itself is extremely dark, the only reason it is seen as bright is because of the amount of sunlight that hits it. When you imagine this, please use the photo above and just remember that the Sun is always on the inside(where the sunlight arrows come from) because of the fact that we orbit the Sun once a year(thus we get the moon to cycle 12 times a year).

We start with the moon being between the Sun and Earth. This means the half of the moon we can not see is getting all the Sunlight, so the half we see is entirely dark. This is important, half of the moon always is lit! If you remember this, the rest will make more sense. This is called a new moon and happens at the beginning of the month(this is how a month was made when a new moon occurred in the past people established that as the start of the month). Now the moon starts to revolve around us while the sun stays in the same spot(for easier reference). The moon is now not directly between the Sun and Earth but is instead at an angle and the moon turns to face us(this revolution happens clockwise). Since it still faces us, a little bit of the moon “turned” to face the Sun, causing the right side to form a crescent of light. This is known as a waxing crescent, waxing because it is “growing” to full moon. This continues to happen until the whole right side becomes lit and is called the first quarter moon. But do not let the name mislead you, half the moon is lit up but we call it a quarter because we can only see a quarter as lit(the other lit quarter faces away from us). Now, this keeps progressing towards the full moon. The stage in between is called waxing(remember, growing) gibbous. I am not aware of the meaning of gibbous, but just remember it because it’s a silly-sounding word. We finally reach the point where the Earth is between the Sun and Moon(notice the order, Sun, Earth, then Moon). This means that the side of the Moon we can see is facing the Sun directly, and is called a full moon(only half is lit, but the full half we can see). This happens in the middle of the month(around the 15th generally). Now the Moon continues to revolve past this point, and as it revolves it turns away from the Sun so to speak, so we see a crescent of darkness form. Because most of the moon is still lit, it is still a gibbous moon but is a waning(shrinking) gibbous. This continues until quadrature or when the moon is at a 90-degree angle to the Earth and Sun(forms a right triangle). This means the third quarter has arrived, as the half of the moon we can see of has half of it lit up(the sunlight is coming from the left, and we look at it straight ahead.) Now past this point, the moon continues to revolve around us, and since it is locked to have the same half keep facing us, it will further turn away from the sun to form a waning crescent(waning because it is shrinking to new moon). Finally, at the beginning of the next month, the Moon returns to its original spot to become a new moon again.

I have discussed the main facts of the moon, the moon’s composition and the phases of the moon. There is obviously a lot more to learn but that is outside the scope of my general discussion, now that you have a starting point, just think of questions and try to answer them.

For Educators

Remember to do your 5-minute presentation on the above topics. These topics are probably the most important things for a general understanding of the moon. Students will struggle with the phases so I would recommend setting up a demonstration (or click this link for a virtual lab). I would recommend doing it in person so students get the 3D spatial understanding, this youtube video does a great job showing a potential experiment and you can be creative from there.

Thank you

Thank you for reading and learning the basics of the moon. If you want to learn more, I encourage you to explore other sources like youtube channels(crash course astronomy is where I learned a lot of my astronomy knowledge) or read books about the moon. Any questions or comments please contact me at vijaypbharti01@gmail.com

Astronomy: What and Why

Before I talk about astronomy, I want to thank you for visiting and ask that if you enjoy what you just read or value our mission here at STEM Enterprises, please support our cause by donating at here. Any donation will be used to provide our highly engaging and effective education(check out the website for what all we do) to students deprived of the opportunity to have a meaningful STEM education experience.

The purpose of this article is to help you understand the joy of astronomy, and can be applied to you as a individual or as an educator trying to spread the love of astronomy. Our education index will attempt to help educators provide education of these topics in a meaningful fashion. If you are an educator, please skim this post for your own benefit and then pay special attention to the for educators section.

Look at the photo above? What do you see? What many people see is that this image looks like a the head of a horse. In fact, what you are looking at is called the horsehead nebula. We will talk about nebulae in a later post, but my point is that what you just did is the essence of astronomy. Astronomy is the viewing and interpreting of the space beyond our world, and it is truly a lovely field. The idea of astronomy can be taken to a science, but in order to love this field I do not want you to think of it as science just yet. Think of astronomy as a form of entertainment. I know a lot of students(myself included) love to play videogames for fun. In the end, what we get out of the videogame can be broadly categorized as such: we can relax, refocus our thoughts to something that we enjoy, and(most important to our discussion and equally unconciously) enhance our knowledge on the game. These categorizations can be directly applied to students, our yourself, to make astronomy as a subject fun. If you have the ability, go outside and look at the stars and let your mind roam. Do not worry about the purpose of doing so, just go out and observe. After a few days of doing so, three things may happen

  1. You may start having questions that you can’t answer like, why does the moon looking different every night, or, why do some of the lights I see in the sky flash and others move fast, or you may just find a group of lights in the sky that you want to learn more about
  2. You have no questions, but found it relaxing to be outside. You may or may not think the sky is pretty(I guess if you live in the city there is not much to see in the sky)
  3. You are angry at me for wasting your time outside and you were bit by too many mosquitoes

And to all three of those responses, I am happy because my goal was achieved. If you were in option 1, the rest of this blog will be great for you, so you can skip to here, move on to my next post. If you were in option 2, the rest of this blog will still be great for you, but keep reading this article. If you were in option 3, I still think I can make this blog great for you so please do keep reading. I want this blog to be educational for option 1 individuals, but I intend to show you how you can have fun for the option two and three folks.

If you were the second option on this list, I ask you to continue to go outside and just stare at the sky. It is not important right now to learn about astronomy, just enjoy the sights you see. If you do not have a good view, get some cheap VR glasses and get an app on your phone for viewing the sky(I have a free one called skyview lite). You may be questioning the purpose of this, but as I said, the purpose is not important. Right now, all I want you to answer me is if you enjoy seeing the stars and want to continue to do so. Then, start actively formulating questions about what you see. These can be brief, just make them actual questions you have. Now think about your two options, you could just google these answers and forget them a day later, or you could go ahead and read my blog, where I probably will answer your questions plus give you an understanding of what astronomy is, while teaching you to enjoy it. This way when you put your VR glasses back on you will know what you are looking at and can encourage your friends to join you(or if you want to show off about how much you know you can do that to.) If you are still not motivated keep reading, otherwise, please let this rest for a day or two then go ahead and read the next post in astronomy. Click here to skip to the end.

Now option 3 individuals, think about what broad fields you do enjoy. Say you like literature. Why do you read the books you do? Character development, the plot, the emotions? What if I promised you that I can produce all of that in my blog about astronomy? I assume you will keep reading this blog. If so, I promise you all of that so please do keep reading, you will truly be fascinated! At this point, think about your broad field like literature and what you find important out of it. As I mentioned with literature, I will do my best to provide you what you would like to see in this blog while teaching you about astronomy so please go ahead and click here and go read the next one after giving a couple of hours for this to sink in. If you cannot think of a broad field like literature that you can enjoy(it can be anything, art, music, math, geography), then there are two options for you

  1. You are a student
  2. You are not reading this

The only reason someone would be as disinterested as I described is that they are a student. For that, I apologize that you are not interested in education, but what I ask you is to read the below section for educators. Although you did not get an education that is encouraged you to be curious, give this blog a shot and see if you can ever find interest in the subject. If not, its no big deal! Try to learn the basics that I will cover in the next couple of posts just to understand what you see a little bit and do what you enjoy! Just while doing what you enjoy, consciously make the effort to try to relate what you enjoy to a broad field. Then start learning in that field as much as you can. You will gain interest in that field, and eventually, be able to return to this post as a option 1 or 2 student from the three options above.

For Educators:

Most of your students will land in this third option. Please accept that fact immediately and understand one thing, you goal should not be to teach them content but to drive interest into learning about it themselves. The problem with school is that teachers provide content, give homework, and then test, but students do not understand the why they should learn it. Instead, what I want you to do is to find out what your students interests are and relate astronomy to this interest. You will really help each student by making it individual or semi-individual. With each of these interests, you can then encourage the student to like astronomy. Say one student is interested in hiking, then you can encourage that student by telling them how astronomy is used to help you know your location while hiking, and learning astronomy will make hiking easier plus you can help pass your time by doing things like identifying the constellations in the sky. I assure you just this is enough to get the students interested, because then they see astronomy as benefiting them! From their, you can teach them. I would highly advise against lectures though. Have them do activities. Each of my blog posts will cover a topic to teach in your class and will come with activities to do! For an idea to structure you class, you can use my post on the subject you want to teach and cover what I write about in about 5 minutes to the students(just tell them about is briefly). Then use the rest of the class to do the activities I list in the bottom(I think they will be in the bottom) of the post to allow the students to learn hands-on.

Thank you!

Thank you so much for reading, and please let me know how I can improve! This is my first blog post so I am really raw to it all but I will continue to make this content as my schedule allows me. Any questions you can contact me at vijaypbharti01@gmail.com