The Sun

“The temperature of the Sun’s surface is so high that no solid or liquid can exist there”- Britannica.com

The Sun is a 4.5 billion year-old, medium-sized, yellow dwarf star composed of mostly hydrogen and helium gas, located on the spiral arm of the Milky Way galaxy called the Orion Spur. With its distance being 93 million miles from the Earth, or 1 AU (astronomical unit), its gravitational force keeps the solar system together and enables life to exist on Earth. According to NASA, the Sun is made up of “super-hot, electrically charged gas” known as plasma; this acts as a catalyst for different parts of the Sun to move at different speeds.

How did the Sun form?

The Sun was formed through the process of a nebula collapsing in on its own gravity, which caused its mass to pull inwards to form our Sun, about 4.6 billion years ago. Most of the remaining material formed the surrounding components of the solar system, such as the planets and their moons, while the remainder blew away by the Sun's solar wind.

Parts of the Sun

Corona: Only seen by the naked eye during solar eclipses, the corona is the outermost atmosphere of the Sun; it is often also referred to as the Sun's upper atmosphere, though it is important to note that it is only a part of it. Temperatures here can range from 500,000 degrees Celsius to more than a few million degrees Celsius. Many solar activities can be observed in this zone, such as sunspots (areas of the sun that can heat up to millions of degrees resulting in an eruption that releases x-rays and energetic subatomic particles), and solar flares (areas of the Sun that appear to be "dark holes" due to them being cooler than the surrounding area).

Did you know: NASA's Parker Solar Probe has flown through the Corona, sampling particles and magnetic fields there, becoming the first spacecraft in history to "touch" the sun on December 14, 2021! For more information, check out NASA's article: https://www.nasa.gov/feature/goddard/2021/nasa-enters-the-solar-atmosphere-for-the-first-time-bringing-new-discoveries

Transition zone: This zone consist of a narrow layer that divides the corona from the chromosphere. Temperatures here rise from about 7700 degrees Celsius to about 500,000 degrees Celsius.

Chromosphere: The chromosphere, located between the transition zone and the photosphere, is a unique layer, in which the temperatures rise the farther you get from the Sun; this is in stark contrast to the lower layers, in which the temperatures rise as you get closer to the Sun's core. Temperatures in this layer can vary from about 3700 degrees Celsius to about 7700 degrees Celsius.

Photosphere: The photosphere is the deepest that we can observe into the Sun so far. The temperature here can vary from 3700 degrees Celsius to 6200 degrees Celsius.

Radiative Zone: This layer is located above the Sun's core. This layer is so thick that it can take photons 170,000 years to pass through. Temperatures here can range from 2 million degrees Celsius to 7 million degrees Celsius.

Core: Temperatures here can be expected to be about 15 million degrees Celsius. This region is where the Sun produces its energy; in fact, the Sun converts 4 million tonnes of matter to energy every second according to the European Space Agency, an intergovernmental organization dedicated to the exploration of space, in a process called nuclear fusion. While this layer of the Sun contains one third of the Sun's mass, it only contains one percent of its volume.

How does the Sun affect Earth?

The Sun is an important component in forming the Earth that we see today. For example, it provides us with a source of energy that enables life to exist through a process called photosynthesis. Furthermore, the sun is capable of causing widespread power outages on Earth through the use of solar wind. Solar wind, generated in the Sun's corona, often collides with the Earth's atmosphere. These disruptions in the atmosphere can cause geomagnetic storms, which can disrupt satellites and create, a phenomena seen usually from the Earth's poles, aurora borealis. It is important to note that when these scenarios play out, most of the time the Earth's atmosphere protects us, thus rendering these storms harmless, though there have been exceptions. And lastly, there are two other unique phenomenon can be observed from the Earth: Solar and Lunar eclipses. A solar eclipse is a scenario in which the moon passes directly in front of the Sun, from the Earth's perspective, causing the moon's shadow to be cast upon Earth; always remember to use special solar filters when viewing this event. A lunar eclipse is when the Earth passes directly in front of the Sun, from the moon's perspective, which causes the moon to appear reddish due to the Sun's light refracting off the Earth's atmosphere.

Special Announcement: We're starting a new instagram series called Celestial Bodies of the Solar System, or CBSS for short! Every other Thursday, we will release an instagram post talking about a celestial body located in the solar system, like the planets, moons, etc.

Thank you for taking time out of your day to read our blog! Comment down below what you found most interesting and if you learned anything new! Make sure to subscribe to our blog and follow us on Instagram to receive updates on new posts and special announcements. Thank you again and keep gazing skywards!

Bibliography

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