"The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun's intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy." -nasa.gov/sun
Astronomy Crash Course on the Sun
How our Sun was Formed
NASA's 10 Need-To-Know Things about the Sun
1. Biggest If the sun were as tall as a typical front door, Earth would be about the size of a nickel.
2. Most Massive The sun is the center of our solar system and makes up 99.8% of the mass of the entire solar system.
3. Different Spin Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 days, but at its poles the sun rotates once on its axis every 36 Earth days.
4. Can't Stand on It The sun is a star. A star does not have a solid surface, but is a ball of gas (92.1% hydrogen (H2) and 7.8% helium (He)) held together by its own gravity.
5. What We See The solar atmosphere (a thin layer of gases) is where we see features such as sunspots and solar flares on the sun.
6. Keeping Everything in Orbit The sun is not a planet, so it does not have any moons. The sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and hundreds of thousands to three trillion comets and icy bodies.
7. Ringless The sun does not have any rings.
8. Under Study Several spacecraft keep the sun under constant observation - learning its secrets and warning Earth about dangerous space weather.
9. Energy for Life Without the sun's intense energy there would be no life on Earth.
10. Nuclear Fusion The temperature at the sun's core is about 27 million degrees Fahrenheit (15 million degrees Celsius).
What Color is the Sun?
In this short video explainer, Universe Today publisher Fraser Cain shows that the Sun might not be the color you think it is. What color is it really, and why can it change?
Size of the Sun
Sun Concept Planner
The Sun's Earthly Impacts
Diagram from the Koshland Science Museum
Climate & Weather
A look at what causes the Earth's climate to change from the British Geological Survey bgs.ac.uk/discoveringGeology
A video on Space.com that explains what we know about the impact of the Sun's Cycle on Earth.
Words to Know
Core the innermost part of the sun where thermonuclear reactions generate energy.
Electromagnetic waves a form of energy which includes visible light, ultraviolet, infrared, and x–rays
Magnetosphere the area surrounding Earth that is influenced by Earth's magnetic field.
Milky Way the galaxy in which the sun is located.
Orbit the path followed by an object revolving around another object, under the influence of gravitation.
Radiation Energy that is radiated or transmitted in the form of rays or waves or particles.
Solar Flare A sudden eruption of intense high-energy radiation from the sun's surface.
Solar Wind A stream of electrically charged particles produced by the sun's corona.
Star A luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun.
Sunspot relatively small, cooler dark area on the sun's surface believed to be associated with the sun's magnetic field.
Get the full word list here.
Teacher Planet gives resources to teach young students about the sun.
"This Lab explores what makes the Sun so volatile and gives you access to the same data, images, and tools that scientists use to predict solar storms." pbs.org
Science NetLinks helps students broaden their understanding of the sun, particularly its critical role in warming the land, air, and water around us.
NASA's look at the Sun, including an overview, an in-depth description, galleries, news and more.