Sun 101 | National Geographic

Summary

The Sun, the heart of our solar system, formed 4.5 billion years ago and is composed mainly of hydrogen and helium in a plasma state. Its core's thermonuclear fusion generates the energy that sustains life on Earth. The Sun's immense gravity and magnetic field, encapsulated in the heliosphere, maintain the solar system's structure and protect it from cosmic radiation. Despite its grandeur, the Sun will eventually exhaust its fuel and transform into a white dwarf, but until then, it remains a vital force in our cosmic neighborhood.

Takeaways

• 🌞 The Sun is the central star of our solar system, formed about 4.5 billion years ago in the Orion's fur of the Milky Way galaxy.
• 🌌 It originated from a solar nebula, where dust and gas collapsed and condensed into a burning ball of gas, becoming our Sun.
• 🔥 The Sun is composed of about 91% hydrogen, 8.9% helium, and 0.1% heavier elements, all in a gaseous phase known as plasma due to extreme temperatures.
• 🔥🔬 In the Sun's core, hydrogen molecules fuse to create helium through a process called thermonuclear fusion, releasing vast amounts of energy.
• 🌐 The Sun's gravity is the primary force holding the solar system together, with the Sun containing approximately 99.8% of the system's mass.
• 🌍 The Sun's gravitational pull is strong enough to maintain the orbits of eight planets, dwarf planets, moons, comets, and asteroids.
• 🛡️ The Sun's magnetic field, encapsulating the solar system as the heliosphere, protects the planets from harmful cosmic radiation.
• 🌐🧲 The Sun's magnetic field is responsible for phenomena such as sunspots and auroras on Earth and other planets.
• 🌕 The Sun is the largest and most massive object in the solar system, with a size that could theoretically contain over 100 Earths.
• 💥 The Sun's life cycle will eventually end in about 6.5 billion years, expanding and then collapsing into a white dwarf.
• ☀️ The Sun's properties of gravity, magnetic field, and energy production are critical for the sustenance and protection of life in our solar system.

Q & A

How old is our Sun?

Our Sun formed about 4.5 billion years ago.

In which part of the Milky Way galaxy was the Sun born?

The Sun was born in the Orion's fur of the Milky Way galaxy.

What was the initial state of the matter that formed the Sun?

The Sun was born from a cloud of dust and gas known as a solar nebula.

What are the six layers or regions of the Sun?

The Sun can be divided into the corona, the chromosphere, the photosphere, the convective and radiative zones, and the core.

What are the main elements that make up the Sun by atom count?

The Sun is about 91% hydrogen, 8.9% helium, and 0.1% heavier elements such as carbon and nitrogen.

What phase of matter are these elements in due to the Sun's extreme temperatures?

Due to the Sun's extreme temperatures, these elements stay in a gas-like phase called plasma.

What process occurs in the Sun's core that releases energy?

In the core, hydrogen molecules fuse together to create helium through a process called thermonuclear fusion, releasing a tremendous amount of energy.

What is the Sun's role in the solar system in terms of size and mass?

The Sun is the largest and most massive object in the solar system, containing approximately 99.8% of all the mass in the solar system.

How does the Sun's gravity affect the solar system?

The Sun's gravity holds the solar system intact, allowing it to hold together a system of eight planets, dwarf planets, moons, comets, and asteroids.

What is the heliosphere and what does it protect the solar system from?

The heliosphere is the Sun's magnetic field that encapsulates the entire solar system, protecting the planets from harmful cosmic radiation.

What phenomenon results from the Sun's magnetic field interacting with Earth's atmosphere?

The interaction of the Sun's magnetic field with Earth's atmosphere results in beautiful Auroras.

What will happen to the Sun in about 6.5 billion years?

In about 6.5 billion years, the Sun will run out of its hydrogen fuel, expand to envelop Mercury, Venus, and possibly Earth, and then collapse into a small star known as a white dwarf.