THE SUN

You should never look directly at the sun. 

The sun's radiation contains not only visible light, but powerful ultraviolet radiation as well,

 which can severely burn your eyes and permanently damage your eyesight.

The sun is a star.

Provides us with energy, which brings life on our planet.

It defines the seasons, the harvests, and even the sleep patterns of all living creatures on Earth.

The sun is the closest star to our planet.

The Earth orbits around the sun.

The Suns radius is 109 times bigger than the radius of the Earth.

Suns radius 696,000km and Earths radius is 6,376km

Suns average surface temperature is 5700C.  Earths average temperature is 20C.

Sun is 150 million km (93 million miles) away from Earth

Sun is 4.5 billion years old

Sun has layers but unlike the Earth, the sun is entirely gaseous, there is no solid surface.

Sun rotates on its axis approx. once every 26 days.

Sun is made of gas, which is why its different parts rotate at different speeds.

The fastest rotation is around the equator and slowest is at the suns polar regions (more than 30 days)

Sun eruptions largest in the solar system. These eruptions at they can reach our planet and cause serious damage by disrupting satellites, and other communication devices.  Our TV may not work, cell phones will be down. We usually have a 2-3 day warning to protect our expensive communication devices during a solar eruption i.e. SOHO

Approximately one million Earths can fit inside the Sun

The center of the Sun, is made of helium

The core of the Sun is approx. 15 million degrees Celsius. The coolest part is nearly 6,000 degrees Celsius.

The Sun loses approx. 4 million tons every second, this is the amount of hydrogen gas that the Sun turns into energy.

The hottest place in the world is Dallol in Ethiopia (Ease Africa).  Average annual temperature is 94 degrees F (34.4C)

The dark blotches on the Sun's surface is called Sunspots.  These are cooler areas of the Sun.

The average number of visible sunspots varies over time,

 increasing and decreasing on a regular cycle of between 9.5 to 11 years,

 on average about 10.8 years.

Sunspots most often appear in the low latitudes near the solar equator,

 and they almost never appear below 5 or above 40 degrees north and south latitude.

 As the sunspot cycle progresses, the visible sunspots move gradually towards the equator.

The earth has a protective cocoon of magnetic field called the magnetosphere,

 and it normally protects us from the magnetic particles of the solar wind, 

and the other energetic particles in the solar wind.

 But during a coronal mass ejection we actually have a chunk of the sun

 that breaks away and hits the earth's magnetosphere,

 and disturbs it, and this disturbance shows up as aurora.

http://www.exploratorium.edu/sunspots/research4.html