The Sun
Introduction:
Our solar system is in the Milky Way galaxy and located in an outer spiral arm. This is where we call “home.” The solar system is made up of some major and minor players, all of which interact with each other.
The solar system consists of our sun, which is a star, and all that its gravity affects. The planets in our solar system are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
There are also dwarf planets such as Pluto, dozens of moons and millions of asteroids, comets and meteoroids of all shapes and sizes.
Our sun is a hot ball of gases that is the very center of our solar system. The gravity of the sun is what keeps all of the planets, moons, and bodies within our system together.
The intense gravitational pull of the sun maintains the orbit of things as small as particles all the way to the gas and ice giant planets.
Solar Statistics:
- Size: 109.2 times larger than our Earth
- Date of Discovery: Unknown
- Discovered by: Ancient ancestors
- Equatorial Inclination: 7.25 with respect to the ecliptic
- Equatorial Radius: 432,168.6 mi/695,508km
- Equatorial Circumference: 2,715,395.6 mi/4,370,005.6km
- Volume: 338,102,469,632,763,000miles3//1,409,272,569,059,860,000km3
- Density: 1.409g/cm3
- Mass: 1,989,100,000,000,000,000,000,000,000,000 kg
- Surface Area: 2,347,017,636,988square mi/6,078,747,774,547km2
- Surface Gravity: 899.0ft/s2/274.0m/s2
- Escape Velocity: 1,381.756 mi/2,223,720km/h
History of the Name:
Our sun has been the center of attention for humankind throughout the ages. Many civilizations gave credit to the sun for survival, food, and warmth. Our sun is the “star” of our solar system and as such, some worshipped it as a god.
The ancient Greeks thought that the sun was a handsome god that they named “Helios.” He was the son of the Titans Hyperion and Theia, and brother to the moon goddess Selene and goddess of the dawn, Eos. Helios’ crown was said to be a sunbeam burst, and each day he would drive his chariot of the sun across the sky that was drawn by fire-breathing-horses.
As he traveled he would deliver sunshine throughout the world and then repeat his rounds every morning after Eos created the new dawn.
As time passed the name of Helios began to be associated with the god of light, Apollo, however, most Greeks maintained them as separate gods.
This was due to the fact that Helios was considered to be a Titan, part of the highest order of gods, and Apollo was a member of the gods known as the Olympians.
The ancient Romans took much of their culture from the Greek and as their empires progressed they worshipped a number of sun gods.
However, in doing so, they replaced the Greek word for sun, Helios, with the Latin root work of “Sol.” One of the most powerful Roman sun gods was Sol Invictus, which translates to “Unconquered Sun.”
We have carried the name “sol” forward to today as it represents anything related to our sun, including our solar system.
Formation:
Our solar system began around 4.5 billion years ago as a huge cloud of gas and dust called a solar nebula. This solar nebula rotated and created a gravity that was so intense that it collapsed.
It continued to spin fast and faster and then flattened into a disk-shape. A majority of the material was pulled into the center to form the sun and its mass accounts for 99.8% of the mass of our entire solar system. Most of the sun is made up of helium and hydrogen.
While we might think of our sun as absolutely huge, it is an average size when compared to other stars. It will eventually run out of energy and begin to die.
When that happens it will enlarge to a size that is so big that it will engulf Mercury, Venue, and probably Earth as well.
Scientists have indicated that our sun has gone through around half of its lifecycle and will continue to shine for an additional 6.5 billion years before it eventually shrinks and becomes a white dwarf star.
Structure and Surface:
Like other stars, our sun is basically a large ball of gas that is 91% hydrogen and 8.9% helium. The sun’s mass is around 70.6% hydrogen and 27.4% helium.
While a majority of our sun may be gas it does have six distinct regions: the core, the radiative zone, and the convective zone in the interior, the visible surface, called the photosphere; the chromosphere; and the outermost region, the corona.
The sun is held together due to gravitational attraction that produces an intense temperature and pressure at the core. The core’s temperature is about 27 million degrees F/15 million degrees C.
This is hot enough to continue the constant state of thermonuclear fusion, a process where atoms combine to create larger atoms and in that process they release huge amounts of energy.
In the sun’s core the hydrogen atoms fuse to create helium.
It’s the energy that is created at the core that acts as the engine that powers the sun and makes all of the light and heat that is emitted from the sun.
Energy at the core is then carried out by radiation and that bounces around for about 170,000 years in the radiative zone until it gets to the top of the convective zone.
Temperatures in the convective zone reduce to 3.5 million degrees F/2 million degrees C, and this is where large bubbles of soupy ionized atoms called hot plasma begin to move upwards.
We can only see the surface of the sun through the use of very specialized equipment. The surface is around 10,000 degrees F/5,500 degrees C and although it’s a lot cooler that the intensely hot core, it’s still hot enough to make elements such as diamonds, carbon, and graphite boil.
The surface of the sun is the photosphere, and it’s around 300 mi/500 km thick. This is the place where most of the radiation from the sun escapes outward. Unlike rocky planets, there isn’t any kind of solid surface of the sun because its outer layer is gas.
The radiation from the photosphere appears as sunlight as it reaches Earth. It takes around 8 minutes from the moment that it leaves the sun to reach our planet.
Atmosphere. Magnetosphere, and Moon Status:
The sun does have a kind of thin solar atmosphere. This is the area above the photosphere where we find the tenuous chromosphere and the crown or “corona.” Through the use of specialized equipment we can view this area to see solar flares and sunspots.
The tops of these areas have visible light that is normally too weak to be viewed against the intensely bright photosphere.
The exception to this is during solar eclipses, when the moon covers the photosphere and the chromosphere appears as a red rim around the sun, and the corona forms a lovely white crown. During the solar eclipses we can see the plasma streamers from the crown that narrow outward and create flower-petal-like shapes.
Oddly, the temperature of the sun’s atmosphere increases with altitude. It can reach as high a 3.5 million degrees F/2 million degrees C. Scientists don’t know why or what causes the coronal heating condition.
The sun generates a magnetic field of electric currents that radiates throughout the solar system. This is called the “solar wind” and it’s a stream of gas that is electrically charges that blows out in all of the directions of the sun.
Since the sun rotates, the stream of particles blows out in a spiral that is called the “Parker Spiral.” When these electrical particles slam into planets and other celestial objects it can cause damage unless stopped or veered off by atmosphere, magnetic fields, or both.
The interaction between the sun and the Earth is what gives us our weather, climate, ocean currents, seasons, radiation belts, and aurorae.
The sun isn’t a static or non-changing star, as it goes through its own phases of the solar cycle. Around every 11 years the magnetic polarity of the sun’s geographical poles change.
When this alteration occurs the corona and the chromosphere change from being calm and somewhat quiet to activity that is violent. The peak of this activity is called a “solar maximum,” and it’s during this time that solar storms occur that include solar flares, sunspots, and coronal mass ejections.
These occurrences are due to the irregularities that are within the magnetic field of the sun and they can release intense quantities of particles and energies.
As they span out into the solar system they can reach Earth as well as cause damage to satellites, affect our power grids, and corrode pipelines.
There are no moons around the sun nor does the sun have any rings.
Could Life Exist?
The sun is not conducive to allowing life as we know it to exist, adapt, and thrive.
It has temperatures and pressures that are incredibly hot and has and plasma mixtures that don’t offer even the basic options for anything to live.
However, it is due to the energy from the sun that life on Earth is possible. Our sun gives us warmth and energy that other organisms such as plants can use to create their food.
Interesting Information:
Our sun is made up of two main gases: hydrogen and helium and is referred to as a “sequence star.”
The creating of our sun happened with two extremely specific situations, the first was that the sun’s mass had to be big enough to be able to allow nuclear fusion to occur.
Scientists have long held discussions on the exact size needed but it’s believed that it needs to be around 80 times the mass of our planet Jupiter. Jupiter is a gas giant made up of the same gasses as our sun.
Had Jupiter grown to equal the mass of our sun nuclear fusion would have happened and we would have had two suns or stars in our solar system. The second situation that is required is that nuclear fusion must happen.
The process of nuclear fusion is when two lighter atomic nuclei fuse together to create an atomic nucleus that is heavier. The two elements in play are the heavy helium and the lighter hydrogen.
When we look at the sky we think that our sun is incredibly large, however, when scientists compare our sun to other stars it’s just a bit larger than average.
The biggest stars in the universe are the red giants and the smallest ones are red dwarfs. When talking about stars, it’s important to remember that the larger the star, the shorter its life will be.
So it’s a good thing that our sun is the right size to have a longer life. Our sun has a diameter of 864,340 mi/1.39 million km, and that’s 110 times the diameter of the Earth. We could put 1 million Earths inside the sun.
As we continue to explore the galaxies we are finding that our sun is just one of many trillions of stars that are in the universe.
Scientists have developed a list of classifications for stars and our sun is listed as a class GV, also known as a Yellow Dwarf star.
The classification of a star isn’t based on size but instead it relates to the surface temperature. Our sun’s surface is between 5,027-5,727 degrees C.
In examining our Milky Way galaxy, scientists think that there are nearing seven billion stars that are similar to our sun.
That means that there could be over 1 trillion stars that are similar to our sun in the universe.
Space Visits:
The largest undertaking for exploration of the sun is the NASA Parker Solar Probe. The design was created to fly seven times closer to the sun than any other spacecraft.
In 2019 it successfully completed a second close approach to the sun, called the “perihelion,” passing within 15 million miles and traveling at 213,200 mph.
During the second perihelion the spacecraft sent back data indicating that the craft was operating well and collecting scientific information.
Facts about The Sun for Kids:
- The mass of our sun makes up 99.86% of the total mass of the entire solar system.
- Our sun is made up of ¾ hydrogen and the rest is mostly helium.
- Every sun has a birth, lifespan and a death. Our sun will continue to shine for around 130 million more years and then it will stop burning its hydrogen and begin to burn helium. When that happens it will expand and grow and eventually engulf Mercury, Venus, and Earth.
- Once our sun begins to expand it will eventually become a red giant star.
- Once our sun enters the red giant stage it will eventually collapse until it nears the size of our Earth and at that time it will be a white dwarf star.
- Gravity is what gives celestial bodies their circular shape and with such powerful gravity, our sun is the closest thing in nature to being a perfect sphere.
- Looking at the sun you wouldn’t think that it’s moving but it’s actually traveling through space at 220 km per second.
- It takes our sun 225-250 million years to complete an orbit around the Milky Way galaxy.
- Once sunlight leaves the sun it travels towards Earth at 300,00 km per second and takes eight minutes to arrive on Earth’s surface.
- Energy that is being created in the sun takes millions of years to travel from the core inside and make its way to the surface of the sun.
- Our sun’s rotation is opposite of the rotation of the Earth.
- There are changes between the distance of the Earth and sun but we don’t really notice them due to the elliptical orbit path of the Earth.
- The magnetic field of the sun is incredibly powerful and can create magnetic storms and solar flares that interfere with our satellites and electronic equipment on Earth.
- The sun has temperatures inside that can reach 15 million degrees C.
https://solarsystem.nasa.gov/solar-system/sun/overview/
https://www.sciencefriday.com/articles/science-diction-sun/
