Amanda is a retired educator with many years of experience teaching children of all ages and abilities in various contexts.
1. The Sun Maintains Life
The Sun is the most important celestial body from the Earth's point of view, as it maintains all life.
The Sun gives us light and heat. Astrophysicists have now worked out that it provides close to 100% of all the energy at the Earth's surface.
In this article, we'll look at facts about not only this astonishing star itself but also the history of our relationship with it and its influence on life on Earth.
A Blazing Star in the Heavens
2. Sun Worship in Ancient Times
Primitive peoples of ancient times worshiped the Sun. Many surviving indigenous cultures still revere the Sun as a god or goddess today.
The earliest Chinese civilizations believed a solar eclipse (when the passage of a planet between the Sun and the Earth blocks it from view) was the “dog of heaven” taking a bite out of it!
The Central American Aztecs offered bloody human sacrifices to their Sun-god, Huitzilopochtli. They believed without these sacrificial offerings, the Sun could no longer make its daily journey across the sky.
The ancient Egyptian culture endured for over 3,000 years. During that time, there were many versions of the Sun-god. One of the most popular was Khepre, the scarab beetle. Just as the real beetle rolls balls of dung across the ground, they thought the divine version rolled the Sun across the sky.
The ancient Romans and Greeks had very similar Sun-gods called Apollo and Helios. These guys had blazing Sun-chariots that they rode across the sky.
Many of the mythical Sun-gods died, to be reborn after a journey to the underworld. This symbolizes the setting and rising of the actual Sun.
The Christian myth of Easter, with the death and resurrection of Jesus, is part of the same solar tradition. And the symbol of the "halo" placed behind the heads of saints in Christian art is a solar symbol from ancient times.
3. The Sun and the Seasons
In ancient times, people thought the Sun traveled across the sky.
We can forgive the ancients for their misunderstanding. From where we stand on the surface of the Earth, it looks as if the Sun rises in the east in the morning, moves across the sky during the day and sets in the west.
Antique Astronomical Map of the Seasons
But it doesn't. It's an illusion.
It certainly doesn't make the journey in a mystic barge or celestial chariot chased by heavenly dogs!
If you stand on a carousel, it seems the world is spinning around you. But you know better. You know the world is still, and you are the one doing the spinning.
The reason the Sun appears to make its journey across the sky is because the Earth itself is turning eastward on its own axis. So the Earth is spinning around the Sun and on its own axis. This explains not only the cycle of day and night but also seasonal progression.
So how is it that the Sun seems to shine brighter and longer in the summer than in the winter?
We've said the Earth's spinning axis tilts toward the Sun. In the Northern Hemisphere (where the USA and the UK are) the height of summer takes place in June. The Northern Hemisphere tilts towards the Sun in June, and in the opposite month of December tilts away.
In the Southern Hemisphere (where you'll most of Africa, South America, and Australia) the situation is the other way.
Heading further to the north or the south, one way or the other, the area exposed to the Sun's light and heat are greater or lesser.
And if you go north of the Arctic Circle, then at midsummer the sun never sets at all!
Check out this great little video that explains everything in an easy to understand and fun way:
4. The Sun Is a Star
Because of the Sun's importance to all our lives here on Earth, we tend to think of it as being unique.
The truth is, the Sun is just one of literally billions of other stars very much like it.
Sun Questions Answered
How old is the Sun?
About 4.5 billion years old
What kind if star is the Sun?
It's a Yellow Dwarf
What is the Sun's diameter?
Approximately 865,373 miles
What's the surface temperature of the Sun?
Our galaxy, known as the Milky Way, hosts about 100 billion other suns. Add to that the fact that many billions of other galaxies are out there and you'll begin to see that in the larger scheme of things, our Sun is not so unique after all!
Not only are there many other Sun-like stars out there but many of them support their own planetary solar systems, too.
Most modern astrophysicists now accept biological life probably exists on many of the planets circling those distant stars.
So if the Sun isn't unique, the chances are that we aren't, either.
5. How Was the Sun Formed?
Our Sun formed about 4.6 billion years ago, making it almost one third as old as the entire known Universe.
The Sun started out as a vast cloud of particle debris left over from the explosive death of an even older star somewhere else in the Universe.
Most of the particles were hydrogen, the most common element in existence.
6. Nuclear Fusion Is the Source of the Sun's Energy
The forces of gravity caused all these particles to draw together. So the swirling mass of particles became denser and denser, collapsing in on itself.
This process generated a huge amount of heat energy because of friction between the particles.
At a certain temperature and speed, the nuclei of the atoms fused together to form helium.
This process is "nuclear fusion". It generates massive bursts of radiation in the form of gamma rays. It takes the gamma rays formed in the Sun's core about one million years to reach the Sun's surface. Yes, the Sun is very, very big!
As the gamma rays travel, they change their frequency until they emerge from the Sun's surface and out into space as visible light.
Light is one frequency range of a universal force called “electromagnetic energy”.
There is enough heat and hydrogen left in the Sun for it to live another 4 billion years before it explodes just as the parent star that provided the original material for its own formation did.
And who knows? Maybe our Sun will start the whole process off all over again. But life on Earth will have become extinct in the cold and the dark long, long before then.
7. How Hot Is the Sun?
The Sun is very, very, very hot!
The Sun's core, the site of all that nuclear fusion we've just been discussing, is the hottest part at a scorching 15 million degrees Celsius. That's 2.7000 x 107 degrees Fahrenheit.
As I said, pretty hot.
The surface of the Sun is relatively cool being a mere six thousand degrees Celsius.
However, the Sun's surface isn't the same temperature all over. If it’s observed through special filters, areas known as "sunspots" can be observed.
Sunspots are areas where irregular fluctuations in the Sun's magnetic field cause solar protrusions. Theses sunspots in themselves are cooler than the rest of the star's surface.
While they are cooler in themselves, the electromagnetic activity they cause can often result in a phenomenon known as a "solar flare".
8. Solar Flares and CMEs
Solar flares are projectile bursts of high energy X-rays.
They cause coronal mass ejections (CMEs), the most explosive events in our whole solar system. When CMEs occur, huge quantities of hyper-electrically charged gas particles known as “plasma” are projected from the surface.
In March 2012 there was quite a scare which gathered a lot of media attention when a vast CME headed Earthward.
The anxiety was that the electromagnetic influence of such an event could have caused a “radio blackout” leaving the entire planet without electricity or communications.
The impact was not as great as people feared. In fact, the most noticeable effect was an increase in the number and size of auroras in the Northern Hemisphere which produced the most beautiful ever seen.
9. How Long Before the Sun Dies?
The Sun will not go on forever.
It will burn up all its fuel and die.
Once the hydrogen element is consumed, the Sun will then burn up its helium. This process will go on for about one hundred thirty million years.
10. How Far Away Is the Sun?
The distance from the Earth to the Sun varies with the time of year as our planet undergoes an elliptical solar orbit.
At its nearest point, the Sun lies approximately 86,991,966 miles from the Earth. At its farthest away, it is about 94,448,420 miles off.
The average distance between the Earth and the Sun is used as a standard of measurement in astronomy and is known as an Astronomical Unit or AU.
Average walking speed is three miles an hour. How long would it take to walk to the Sun?
During that time the area of the Sun will expand and it will become much brighter and hotter until it destroys life on Earth, evaporates the oceans and consumes the entire planet along with our nearby planets, Mercury and Venus.
The Sun is a kind of star known as a Yellow Dwarf but at that stage it will have become a Red Giant.
There is another phase following that as, once the expansive energy is all burned up, the Sun will contract again to a dense nugget about the size of the Earth that it will have destroyed. Stars at this stage are “White Dwarfs”.
Bye Bye, Sun!
And so our journey to the Sun comes to an end. Pretty hot stuff, right?
There's a lot more to learn about our nearest star and you can find out more by visiting the NASA website and searching the solar observatory.
If you have something to say or a question you'd like to ask, please go right ahead and do so in the comments box. It would be great to hear from you!
Have you tried the Sun Quiz?
Give it a go and see how you do!
© 2014 Amanda Littlejohn
Got something to say? Well come right out an' say it!
Amanda Littlejohn (author) on April 10, 2017:
Hi rebelogilbert and thank you so much for your interesting contribution. The sun is certainly a fascinating subject!
Bless you. :)
Gilbert Arevalo from Hacienda Heights, California on April 08, 2017:
Amanda, you put together a very fun and important article about the sun. You included great photos and videos with a fun writing style, but it's awfully frightening thinking about sun expansion days. I learned about that fact from other astronomy books. I used to think with age the sun would get weaker and cold, not hotter, amazing, the chemical make-up of the sun.
Amanda Littlejohn (author) on March 07, 2015:
Thanks. Glad you found it that way.
Aliur on March 07, 2015:
Informative and easily understandable.
Amanda Littlejohn (author) on May 12, 2014:
Thanks for your comment. I'm glad that you enjoyed reading these facts about the Sun and were especially interested in the ancient Aztec's Sun worship.
Bless you :)
manatita44 from london on May 11, 2014:
No need to tell you that you chose a really powerful topic. The Aztecs were quite clever, and very much in tune.
Great video. Probably has more uses too.
Good to hear that the kids are independent. Enjoy your Mother's Day.
Amanda Littlejohn (author) on April 22, 2014:
Hey, thanks so much for reading this and your kind comment. Glad you found it interesting.
Bless you :)
Devika Primić from Dubrovnik, Croatia on April 22, 2014:
Great hub! Educational and informative.
Amanda Littlejohn (author) on April 12, 2014:
Thank you so much for your enthusiastic appreciation, *blush*
We hear so much about Mars these days because of the on-going explorations there and the future plans for colonization but the very heart of our solar system is too often neglected.
For life on Earth, it is the Sun that will determine our ultimate fate. Of course we might have gotten far enough away to survive in the next billion years or so but by then - as evolution is an on-going process - we almost certainly won't be human any more.
As they say - Cosmic!
Suzie from Carson City on April 12, 2014:
Amanda.....A very interesting, useful and worthwhile educational hub! Well-presented, I appreciate the research done. Together with your obvious talent of sharing information with your readers...this hub is a winner!...UP+++
Amanda Littlejohn (author) on April 11, 2014:
Thanks for your generous comment. I'm so happy you enjoyed this article about the history of the wild west.
Bless you. :)
Carrie Lee Night from Northeast United States on April 11, 2014:
Very good hub ! :) Great use of visuals and text. Thank you for taking the time to write this educational hub. Have a great week.
Amanda Littlejohn (author) on April 09, 2014:
Thanks for your comment and contribution to the hub.
I agree that this information is real and I think I know what you mean about 'miracles' if you mean that this stuff inspires awe and wonder and really stretches the imagination to comprehend. Totally with you, there!
But I do think it is fun, too. Maybe not 'light-hearted' but still fun.
Thanks again and bless you. :)
icv on April 09, 2014:
very nice hub on this topic. these are not fun but real and miracles. thanks for sharing...
Amanda Littlejohn (author) on April 08, 2014:
Thanks for your kind words. Yes, I'll check out your hub, for sure!
Bless you :)
Amanda Littlejohn (author) on April 08, 2014:
Hi Flourish Anyway!
Thanks for stopping by - I hadn't really thought about Easter when I wrote this. Still, the Sun is a fascinating subject from any angle.
Thanks for your contribution.
Amanda Littlejohn (author) on April 08, 2014:
Thanks for reading this and for your generous comments - your opinion is always of value.
While I studied life sciences, I still find astronomy and cosmology fascinating.
Bless you :D
Harry from Sydney, Australia on April 08, 2014:
Great hub! .. I'm always fascinated by the cosmos ...please take the time to read my article on the Solar System.. Cheers!
FlourishAnyway from USA on April 08, 2014:
Very timely with Easter near. I learned a lot with this great hub of yours, Mindi! Well done with so much diversity of interest areas and educational value, too!
Bill Holland from Olympia, WA on April 08, 2014:
Well, as an old science and geography teacher, that was definitely interesting. What a great resource for kids. Well done my friend.