Transcription
15 Mindblowing facts about the Sun. The presence of the Sun is so precious for life as we know it. It has extremely important influences on our planet: It drives weather, ocean currents, seasons, and climate, and makes plant life possible through photosynthesis. Without the sun's heat and light, life on Earth would not exist at all.
All over the years, astronomers have tried to figure out what the sun is, how old it is, and a bunch of other things…for example, does it have a magnetic field? What is its mass? In this video, we will go through a series of amazing facts about our sun. Fasten your seatbelts! Let’s go! (roll intro)
First of all, 15. THE SUN IS VERY OLD. It is one of 100 billion stars in our Milky Way galaxy. Scientists estimate that the Sun is about 4.5 billion years old. We never measured the age of the sun directly; it would be impossible. All that we have are indirect methods to estimate it. To have an idea, we look at the age of the whole solar system, because we assume it all came together around the same time. To get this number, we look for the oldest things we can find. For instance, moon rocks work well for this. That’s the reason why, when astronauts went to the moon, they brought some rocks back for scientists to study them; they were able to find out how old they are.
A really important thing to know is the composition of the Sun. Observing it in the sky, we might think it has the shape of a ball, or we could suspect it is a sphere. Sure, that’s true, but…how is it made? Well, we know that… 14. THE SUN IS NOT SOLID! It is composed of plasma, a material made from electrically charged gas atoms. It is about 75 percent hydrogen and about 25 percent helium. The remaining traces are tiny amounts of metals. A really interesting thing is that Jupiter has the same composition as the sun. If the sun were smaller, it would just be a huge ball of hydrogen akin to Jupiter. The hydrogen in the sun's core is held together by a lot of gravity resulting in high pressure. The pressure is so high that when hydrogen atoms collide with enough force they create a new element — helium — in a process called nuclear fusion. The continual nuclear fusion causes energy to build up and the sun's core reaches temperatures of about 27 million degrees F (15 million degrees C). The energy then radiates outward to the sun's surface, atmosphere, and beyond. We can feel this energy on Earth: we can feel the heat of the sun on our skin. It is what helps us dry our clothes every day. The amazing thing however is that... 13. THE SUN IS REALLY FAR AWAY.
It is about 93 million miles away from Earth. If we wanted to sort all the planets from the closest to the furthest, we would come out with this list: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, with Mercury being 35,000,000 miles away from the sun, and Neptune lying 2.8 billion miles away from it. An easy mnemonic often used for remembering the order is “My Very Educated Mother Just Served Us Noodles.” But I think it’s time to change it because it might sound a bit sexist. Do you have any other simple ideas? Let us know in the comments below!
Oh, I forgot to mention that 12. THE SUN IS HUGE. It is about 865,000 miles in diameter! To get a better idea, that’s as wide as 109 earths placed side by side! Oh, and something like 1 million Earths would fit inside the Sun. Amazing, isn’t it? This giant object wonders in space. What we know is that 11. IT MOVES VER-R-R-Y SLOWLY. The Sun is the center of our solar system, of course, but it doesn’t stay in one place. It orbits the center of the milky way galaxy, and it takes the Sun about 226 million years to go around the galaxy once! For comparison, the dinosaurs went extinct around 65 million years ago. However, not only the sun orbits the milky way center. It also rotates around its axis in the same direction as Earth does, i.e., counterclockwise, when looking down from the north pole. But … 10. SECTIONS OF THE SUN SPIN AT DIFFERENT SPEEDS.
Because the Sun is gaseous, different sections rotate at different speeds. At the surface, the area around the equator rotates once about every 25 days. The Sun’s north and south poles rotate more slowly. It can take those areas more than one month to complete one rotation. As fact number seven, 9. THE SUN HAS A LOT OF PULL. It makes up more than 99 percent of the total mass of the solar system. Being this massive, the Sun exerts a lot of gravity, or pull, on the planets — enough to cause them to orbit around it. When people understood this, it was mindblowing. The Kepler laws describe how the planets orbit around this pulling monster. Believe it or not, the Sun’s gravity is about 27.9 times that of Earth's. Don’t ask how, but astronomers found a way to quantify the energy coming from the sun. What they discovered is unbelievable. 8. THE SUN IS AN ENORMOUS BALL OF ENERGY. The Sun’s core is under a lot of pressure. Because of this, hydrogen atoms are constantly colliding with each other at great speeds, fusing to form helium and releasing energy. But where does this energy come from? Well, lots of these collisions occur, creating an enormous amount of energy. Think about this: in just 1 second, the Sun produces about 118 trillion times as much energy as the United States used in the year 2003! Fact number 9 might seem obvious, but it’s worth reminding you that… 7. THE SUN IS HOT. Even if it is not your boyfriend or girlfriend. Its temperature is not constant: it varies over time and through its eight layers. One thing is sure: the hottest part of the Sun is the core, at 28,080,000 degrees F, on average. And did you know that… 6. THE SUN HAS SPOTS?
This is due to its magnetic field. When the Sun’s magnetic field pokes through the surface, it prevents the heat rising inside from coming through. Some kinds of tubes are created where the divergence of the magnetic field is constant, making the pressure lower in the tube and therefore lowering the temperature. As a result, the Sun’s surface in these areas is cooler and darker than its surroundings, although still very bright. These dark areas are called sunspots. Sunspots are not permanent and they can move slowly across the surface of the Sun changing size as they move. By observing them, in principle, one can get the rotation velocity of a star. The appearance of sunspots on the sun also follows the solar cycle of eleven years. What does this mean? Every eleven years there will be a period of increased sunspot activity. Sunspots vary in size from as small as 10,000 miles across to as large as 100,000 miles across.
Hey, if you are enjoying this video, you should watch our video about the solar system. You will find some mindblowing facts about our place in the universe. https://www.youtube.com/watch?v=3Gu0RdEyxL8&t=83s
We said the Sun has a magnetic field, but do we know anything about its shape? Well, as a first approximation, 5. The magnetic field of the sun has a spiral shape. It’s called the Parker spiral. As the Sun rotates, its magnetic field twists into what’s called an Archimedean spiral, as it extends through the Solar System. This phenomenon is often called the Parker spiral, after Eugene Parker's work. This guy predicted the structure of the interplanetary magnetic field! Did you hear me well? He predicted it! With equations! The influence of this spiral-shaped magnetic field on the interplanetary medium (solar wind) creates the largest structure in the Solar System, the heliospheric current sheet.
4. You should be careful not to get too close to the Sun, and that’s because you could get instantly pulverized. We know this because sometimes areas of the Sun suddenly appear much brighter. These bright spots are called solar flares. They are areas where a large amount of energy is released to the surface of the Sun. Solar flares emit bursts of electromagnetic radiation including high-energy X-rays and gamma rays. The energy released by a single solar flare can be more powerful than a million nuclear bombs going off at the same time. Here’s what they look like. These monstrous flares are made of particles, and when they are released, they can reach Earth in just a few minutes. These particles can damage electronic components in satellites and can also affect some radio signals.
Perhaps the most important fact about the Sun is that… 3) It is a pretty average star. Our Sun is not so special in the universe. It is an average-sized star: there are smaller stars and larger stars, even up to 100 times larger. Many other solar systems have multiple suns, while ours just has one. Our Sun is 864,000 miles in diameter and 10,000 degrees Fahrenheit on the surface. For instance, we have found stars that are 100 times bigger in diameter than our sun. Truly, those stars are enormous. We have also seen stars that are just one-tenth the size of our sun. For instance, the Sun would be just a small dot if compared to Stars like Rigel and Aldebaran. However, maybe the sun is a bit unusual, in the sense that…we don’t find it in a multiple-star system. It is not bound to any other close star. It's just one Sun surrounded by planets, asteroids, comets, and dwarf planets. But solar systems can have more than one sun. That's often the case. More than half of all stars are in multiple-star systems. That means that in general, other star systems have two or more suns in them. Can you imagine having two suns in the sky at the same time? Well, there are plenty of planets throughout the universe where that is normal. Multiple sunsets, multiple sunrises, what a life that would be. Or maybe not. Fact number 14.
2) The Sun is approximately halfway through its lifespan. If it was a person, we could say he is almost forty, I guess. Since we said it was four and a half billion years old, it still has something like 5 billion years to go. And when those five billion years are up… 1) the Sun will become a red giant. Our star will get bigger and cooler at the same time. When that happens, it will be different than the Sun we know today. As a red giant, our Sun will become about 2,000 times brighter than it is now! And we would be long gone. Hopefully.
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