Astronomy: Our Solar System

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

  1. Introduction/The Sun
  2. Inner Planets
  3. Asteroid Belt
  4. Outer Planets
  5. Kuiper Belt
  6. Oort Cloud
  7. For Educators
Embed from Getty Images

Now that we know of the moon and Earth, we will be diving into the planets. This post will be an overall description of what we call our solar system, which is everything that orbits the Sun. This orbit is caused by the gravitational pull of the Sun. I won’t describe how that works currently but if I do, I will replace this line with a link to the blog post explaining what is known as Newton’s Law of Gravity and Kepler’s Laws(these help us describe planetary motion).

For now, lets talk about the solar system. It starts with our Sun, which is a very large(2*10^30 kg and radius of 700,000 km) “ball” of mainly hydrogen plasma(superheated gas for our purposes). The sun is 1 Astronomical Unit, or AU, from us(Earth), which is equal to about 93 million miles. The important thing is that the Sun releases a lot of energy in the forms of light and charged particles, which account for us having heat and many other interesting phenomena. Also, the Sun is what holds everything together, because the Sun is 99.8 percent of the total mass of the Solar System(Jupiter is literally insignificant in mass to the Sun).

The Terrestrial(Inner) Planets

Next we have the four terrestrial planets, which are, in order of increasing distance from the Sun, Mercury, Venus, Earth, and Mars. These are called the terrestrial planets for two reasons, one, they are primarily rock and do not have much of a gaseous component(less atmosphere) and they are separated from the rest of the planets by the Asteroid Belt. The term terrestrial is used to say that each of these planets are like Earth. They all have rocky cores made of iron and nickel.

Asteroid Belt

The Asteroid Belt is composed of small rocks that could not aggregate together like moons and planets do. These small rocks are asteroids(I say small but the smallest asteroids are more than a half mile across). They separate Mars and Jupiter. This belt is huge, but most of the mass is aggregated into 4 large asteroids, the largest being called Ceres. This asteroid is considered a dwarf planet and is 500 kilometers in radius(The Earth is 6400 kilometers for reference). The asteroids are very sparse, meaning most of the belt is empty space. Finally, these asteroids are also called planetesimals because they are considered the pre-requisites to the formation of a planet.

Jovian Planets

Pass the asteroid belt to find Jupiter, the first of four Jovian Planets. Jovian means “Jupiter-like”, so all of these planets are like Jupiter. The planets after Jupiter are Saturn, Uranus, and Neptune. These planets are gas giants, because they are much larger than the terrestrial planets and are mostly gaseous. Note that these planets are much farther away from the Sun than you might think, the distance between planets is not proportional. From Earth to the Sun, as we said, is 93 million miles, while Jupiter to the Sun is 500 million and Uranus is 1.8 billion miles away from the Sun. Jupiter is the largest, Saturn has the rings that you probably know about, and Uranus and Neptune are very similar, the biggest difference being how far from the Sun they are(Neptune’s year is double that of Uranus’s approximately).

Kuiper Belt

Beyond the Jovian Planets lies the Kuiper Belt. This begins around 50 AU(astronomical units/ 1 AU= distance from Earth to Sun) beyond the Sun. The belt is very similar to the asteroid belt, except you will find more comets and ice rocks because of the extremely cold temperatures. This belt is also very sparse in rock density(mostly empty space), but is also much larger than the Asteroid belt.

Oort Cloud

Finally, let’s discuss what is known as the Oort Cloud. This is just barely part of the Solar System, it is 2,000 AU away from the Sun(remember the Kuiper Belt is only 50 AU). This ‘cloud’ is believed to be a large sphere of sparsely populated ice rocks. However, sparsely populated does not mean underpopulated. It is believed to have trillions of different objects. Because of how far away it is, this cloud is just speculative and we do not know if anything really exists there except for very long period(time per revolution around the Sun) comets.

For Educators

After doing the five minute presentation on the subject(make it however you feel like, just stay away from talking too much, visuals and audio are more useful). Afterwards, you have a couple of main goals.

  1. Explain how the composition of the gas giants and terrestrial planets differ
  2. Get relative distances between the planets

For goal 1, the easiest way is to explain gas giants as being like cotton candy(you could fill a bag with cotton candy to make it round like a planet). Since they are gaseous, they do not have much solid like behavior and will be fluid(this is much less dense than the actual densities of Jovian Planets, but will convey the point). Note, however, since they are so massive, they will make you feel heavier on these planets(gravity is more than here on Earth.) For terrestrial planets, you could use a rock because these terrestrial planets are very dense(mostly rock). Make the rock round to reflect a planet. Even better is have the students make these planets from some materials and paint them(you could use something like Styrofoam for the Jovian Planets and actual rocks for the terrestrial planets). Please remember that for Jovian Planets are much denser than Styrofoam or cotton candy, I am just using those to convey the “texture” of the planets in a easy to understand way. Most of the density would come from the mass of the Planets packing the gases in the core to make it solid.

For goal two, I am using a very easy to understand description from NASA. ” One way to help visualize the relative distances in the solar system is to imagine a model in which the solar system is reduced in size by a factor of a billion (109). The Earth is then about 1.3 cm in diameter (the size of a grape). The Moon orbits about a foot away. The Sun is 1.5 meters in diameter (about the height of a man) and 150 meters (about a city block) from the Earth. Jupiter is 15 cm in diameter (the size of a large grapefruit) and 5 blocks away from the Sun. Saturn (the size of an orange) is 10 blocks away; Uranus and Neptune (lemons) are 20 and 30 blocks away. A human on this scale is the size of an atom; the nearest star would be over 40,000 km away! “(See the link below for the source). ” What they are saying here is that if you scaled everything down to a very small size, you could use these numbers to explain the relative sizes and distances of the planets. Students do not need to remember any numbers, rather they should get the concept that things are not proportional. I would recommend taking students on a walk for things like the distance to Jovian Planets since they are quite large.


Thank you

Thank you for reading! Any questions or comments, let me know at

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

Astronomy: Before Space

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.

Image received from Earth Science by Tarbuck and Lutgens

The basics of astronomy start from our own planet, Earth. Our planet has been instrumental in understanding how outer space works so it is critical to get a simple understanding of our planet. Step 1 is the atmosphere. The atmosphere is essentially what we see when we look up, and it has multiple intersecting layers. The image above is really useful in understanding how the atmosphere works. I recommend reading the book in it’s caption to learn everything there is about Earth. Eventually I will have a blog on Earth Sciences also.

The atmosphere has 4(5 to some) main layers. The term layer is loosely used to describe a slice of the atmosphere that has similar properties. Layer 1 is the troposphere, so named because the phrase tropos means change(all of the layers end with sphere because sphere means realm, or region, that is why atmosphere is region of air(Atmos)). The change in troposphere means the fact that all weather occurs in the troposphere, so it is not constant. We see things like clouds in this region which goes vertically up 6.214 miles(10 kilometers). This is equivalent to 32809.92 feet, for perspective. When you are in a plane, you are in this region since planes fly at about 5-8 miles up.

After the troposhere comes the stratosphere, where stratos means layer. This shows that their is really not much happening in this layer except this is where the ozone layer you may have heard of exists. The ozone layer is a layer of trioxygen(3 oxygen) gas that prevents radiation from abundantly hitting the surface.

The next layer is the mesosphere, named such because it is the middle(meso) layer. In this layer, the air is very thin but the last layer to have mixed air(the gases like Nitrogen and Oxygen that make up the air are dispersed) but still exist. This is where you see meteors burn up, what we call shooting stars! This layer goes up to 80 kilometers. The top of the mesosphere is extremely cold(the coldest part of the atmosphere).

Finally we have the thermosphere(and some split the top of the thermosphere to the ionosphere, but I am not going to do that and discuss them as one). This layer starts at 90 kilometers and extends into outer space. We have nearly reached the stars! In this layer, air is extremely thin and separated based off different chemicals(why they split is a little complicated but has to do with reactions to UV radiation). This layer has extremely hot particles(1000 degree Celsius) but since the amount of particles are so little, it would not feel hot. This is the layer that produces the Auroras we have seen in photos(Northern and Southern Lights) because the UV radiation excites the ions in this sphere causing them to give off light as they relax. I’ll talk about how stuff like that works in a chemistry blog.

For Educators:

You can do a short presentation on the different layers of the atmosphere, but more importantly, teach students how air density/pressure decreases with altitude. Remember this is caused by having less particles of air at the higher altitudes. This can also be shown by being cold(if something is cold it means the particles are sparse and/or slow). For inspiration, check out this YouTube video

Thank you!

That is about it for this blog! We have launched off from Earth and have reached outer space. I will see you in the next blog. Contact me with comments at!

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

Education Index

Hi! This is Vijay Bharti, VP, and Treasurer of STEM Enterprises. This is just a test post that may or may not stay on the website but regardless, I am planning on starting an educational blog for STEM. We will be talking all sorts of cool educational stuff, my idea, for now, is to take stem subjects and break down the concepts into easy to understand features. How this will work, I have not figured out but I am just typing this out to get the ball rolling. Hopefully, we will be able to create an education index where anything one wants to know can be found on this site(with regards to certain subjects). I am hoping to get started with my first post soon, until then. I’ll let this post be the starting point. Once I get some posts out I will work on formatting also so apologies in advance for if it doesn’t look good(though I do not see anyone really reading this). If you have ideas you want to share if you want to write an article about something, please let me know!