Scientists believe that the sun formed within the cluster of several thousand other stars. The Sun is 865,000 miles in diameter and the right size to burn consistently for a very long time, like 8 billion years. The solar system lies about 26,000 light-years from the center of our galaxy, the Milky Way, or around two-thirds the way. The story of how these vast planets came to be orbiting an average yellow star is 6 billion years long.
It was the year 1543 when Nicolaus Copernicus finally published his work proposing a Sun-centered model. Unfortunately, Copernicus’s model was also pretty top-heavy and had a hard time predicting planetary motions. Astronomer Johannes Kepler made a brilliant mental leap: Based on observations by his mentor Tycho Brahe.
Kepler realized the planets moved around the Sun in ellipses, not circles as Copernicus had assumed. This fixed everything, including those aggravating planetary motions. The term “solar” comes from the word “sol,” for Sun. There are lots more asteroids scattered around the solar system, but most are in the central belt.
How sun was born?
About 4.5 billion years ago, gravity built a cloud of dust and gas together, which might have come from the explosion of a nearby star called a supernova. This massive concentration of intestinal gas and dust created a molecular cloud as it would form the sun’s birthplace. The cloud began to collapse under its gravity for cold temperatures, forming young stellar objects known as protostars. As Dravid repelled the gas and earth together, it made a cloud start to collapse, forming a sole nebula.
As it collapsed, the cloud began to spin. Eventually, the cloud is hotter in the center, with a disc of gas and dust surrounding it. And it was new at the edges. As the disk got, thinner and thinner particles began to stick together and form clumps. Some of them got bigger, eventually forming planets and moons. So near the cloud center, only rocky material could stand the great heat like Mercury, Venus, Earth, and Mars. Around the new Sun, there was still a spinning disk of gas and dust. Over time it cooled and came together due to magnetism and gravity. Close to the Sun, metals, and rocks began to form, but it was still too hot for other materials to become solid.
Fast forward 100 million years, and it had grown into a giant ball sweeping up billions of tons of celestial. This is where the earth came from. About 93 million miles away, at the heart of the giant nebula, the pressure and temperature of a ball of hydrogen gas had become so great that the atoms were beginning to fuse. Every nebula is different, and the clouds contained nitrogen, oxygen, iron, silica, and all the other stuff needed to build a planet.
Then the tireless force of gravity started to pull it all back together, and the heavy engineering that produces planets began. As a cloud continued to fall in the center eventually got so hot that it became a star. Today we call it the Sun. The new star below all the gas and dust of the new solar system with a solid stellar weight. By stirring meteorites leftover from this early phase of the solar system, scientists have found that the solar system is about 4.6 million years old.
As the Sun ignited, it gave off a massive blast of solar wind and a radioactive gust of energy. It blew all the remaining dust and gas left over from out to the edge of the solar system.
Size and Distance:
- About 93 million miles from Earth.
- The Sun’s volume is 1.3 million bigger than Earth’s.
- The Sun radius is 432,168.6 miles (695,508 kilometers).
Speed & Orbit:
- The average velocity of the Sun is 450,000 miles per hour (720,000 kilometers per hour). It takes about 230 million years to make one complete orbit around the Milky Way.
- The axial tilt of the Sun is 7.25 degrees to the plane of the planets’ orbits.
The Sun spins around 25 days at the equator, but it rotates once on its axis every 36 Earth days at poles.
- Like others stars, Sun is a ball of gas.
- It is made of 91.0% hydrogen and 8.9% helium. By mass, it is about 70.6% hydrogen and 27.4% helium.
The Sun has six regions: Radiative zone, Core, Convective zone in the interior, Visible surface (photosphere), Chromosphere, Corona.
- At the core, the temperature is about 27 million degrees Fahrenheit or 15 million degrees Celsius.
- The surface of the Sun is about 10,000 degrees Fahrenheit (5,500 degrees Celsius).
Sun energy formation (Nuclear fusion)
At the core, the Sun gives birth to light forged and one of the most violent reactions in the universe nuclear fusion. The specific nuclear reaction that powers the Sun is fusion. It is a process to convert hydrogen into helium. Two hydrogen atoms make a helium atom. It’s hard to get two atoms to fuse two protons.
They have the same charge, and both are positively charged. So they want to repel each other. For the fusion reaction, protons have to come together with a vast energy or velocity to get close enough. That’s very rare to force protons together takes immense amounts of heat and pressure generated by the invisible hand of gravity.
The Sun contains 99.08 percent of all the matter in the solar system. That’s a lot of mass, and all that mass pulls the Sun together with unimaginable gravitational force. Both gravities crushing things down, things get close enough together, and nuclear fusion happens. In this nuclear compactor, hydrogen atoms slammed together 100 million quadrillion times each second.
Some of these collisions are so powerful that atoms fuse, releasing energy. When the protons come together to bind, they lose a little mass, which gets converted into energy. Every second of every day, about 5 million tons of stuff is being converted to energy.
Sun axis & Sunspots
It was Galileo Galilei who in 1612 observed sunspots moving across the sun’s discovery of the time. Sunspots occur where the sun’s plasma interacts with its magnetic field, leading to solar flares and other types of solar storms. So the Sun does rotate, but it doesn’t spin all at the same rate because it’s gas. The Sun isn’t a solid object like a planet. The Sun rotates fastest at its equator. On the sun’s equator, any point takes 24 days to rotate completely around the star, while the poles take more than 30 days.
These measurements have been made using sunspots as tracers of the surface and watching them turn with a star. Astronomers usually work with a rotation rate of an area about 26 degrees above or below the equator. This is where most sunspots are observed. One complete rotation takes over 27 days at this latitude, known as a Carrington rotation. The inner parts of the Sun also spent faster than the outer layers.
Solar system formation
The sun’s birth is essential for the solar system because it is the primary source of energy. How solar system formed? When this giant cloud collapsed, it had a little bit of angular momentum. So not all the matter collapsed into the central star-forming region. The material also began to orbit around the protosun forming a protoplanetary disk roughly 200 au in diameter. It is in this disk that the planets started to form.
The disk was composed of gas and dust. Cosmic dust is comprised of tiny rock particles less than a micron in size. These grains began to stick together and grew in size until they formed one kilometer wide objects known as planetesimals. They were gravitationally attracting each other. And as a result, they continued to grow in size through a process known as accretion.
- It’s thought that the inner solar system at this point contained 50 to 100 moon to mars size objects known as planetary Embryos.
Further from the Sun, where it was more relaxed, water and other ices could form. They came together to make larger pieces called planetesimals which then joined to make giant planets. These planets had enough gravity to capture the surrounding gas and became the gas giants Jupiter and Saturn. Some scientists think Jupiter formed first and was pulled towards the Sun by the swirling material in the inner disk.
When Saturn started, it moved inwards too. The planets got closer and swept up the gas between them. They then began to journey outwards together. Jupiter’s large size stopped rocky material from clumping together. The asteroid belt is full of these rocky scraps of the Solar System.
When Jupiter moved inwards, it fed on lots of material, so later, Mars had less to form. In the inner Solar System, chunks of metal and rock slowly created the rocky planets. Within 100 million years, early planets were orbiting the Sun with lots of leftover material in between. The young Sun had a phase of releasing strong winds. It blew the extra gas outwards, stopping the rocky planets and early gas giants from growing. The outwards moving gas was pulled around the snowball cores of the ice giants Uranus and Neptune in the outer Solar System.
Many of the leftover ice balls flew out into the spherical Oort cloud. They occasionally got flung inwards, becoming comets, and collided with the rocky planets. Perhaps comets brought ice and gases back to these planets providing material for their atmospheres and bringing water to the Earth. For the first billion years, any stray pieces of rock and ice would have been flying around, creating many collisions.
The Earth’s Moon could be the result of a large object impacting the Earth. Similar impacts may have reversed Venus’ spin and knocked Uranus onto its side. Some of the planetesimals still floating around were captured by the giant planets to form Moons around them. Scientists are looking at distant stars with exo-planets to see how they form. Based on observations of other stars, astronomers predict Sun will die in about another 10 billion years later.
- Evolution Of Life On The Earth Timeline
- How Earth Was Born Step By Step?
- How Does The Earth Rotate And Revolve On Its Axis
Pitjeva, E. V.; Standish. “Proposals for the masses of the three largest asteroids, the Moon–Earth mass ratio and the Astronomical Unit.”
Williams, D.R. “Sun Fact Sheet.” NASA Goddard Space Flight Center.
Zombeck, Martin. Handbook of Space Astronomy and Astrophysics 2nd edition. Cambridge University Press.
Asplund, M.; Grevesse, N.; Sauval. “The new solar abundances – Part I: the observations.” Communications in Asteroseismology.