The Sun

Throughout history, the Sun has been central to cultures all over the world. In Saskatchewan, the Nakawe understand

that the Sun sees all, even through clouds and storms. Because of this and the light the Sun gives-both spiritual and physical-it inspires us to achieve excellence in all

we do.

-Pearson Saskatchewan Science 9

The Sun: An Important StarThe Sun supports almost all life on Earth. It

provides the energy needed by all plants and animals on Earth

Because the Sun is the closest star to the Earth, it is also the brightest object in the

sky.

It sends out so much light energy that you can not see the other stars until the sun

has set.

Where Does the Sun’s Energy come from?

Like all stars the sun produces energy through a process called

nuclear fusion. Nuclear Fusion: a process during which substances fuse to form new substances, releasing huge amounts of heat, light and

other forms of energy.

How Much Energy?

Every second the sun makes more energy than humans have used throughout our entire history.

Scientists have calculated that the sun has been producing energy for about 5 billion

years.

Scientists estimate that it will continue producing energy for about another 5 billion

years.

A Closer Look at the Sun

Space Probe – Ulysses was launched in 1990 to study the poles of the sun

SOHO – has 12 special instruments for observing the sun

A Breakdown of the SunCorona: the hot outer part of the Sun, where the gases reach temperatures of about 1 million degrees Celsius.

Chromosphere: the inner atmosphere of the sun

Photosphere: called the surface of the Sun, although it is made up of churning gases, not a

solid surface at all.

Core: where nuclear fusion produces the Sun’s energy. Temperatures here reach 15 million degrees Celsius and

the pressure is enormous

Solar PhenomenaSunspot: a region on the Sun’s surface that is cooler than the surrounding areas. Although still very bright, by contrast it looks darker than the surrounding areas.

Sunspots indicate regions where the magnetic field

is extremely strong, slowing down

convection. This prevents the plasma

from mixing, allowing the region to cool.

Solar Prominence: is a large, low energy, curved, bright stream of particles.

The electrically charged plasma in the prominence is shaped by the Sun’s magnetic field lines. This makes part of the magnetic field visible. The curved shape often forms a complete loop and may last for several hours or several weeks.

Solar flare: is a high energy massive explosion at the surface of the Sun. This sudden release of magnetic energy often flings hot plasma out into space. It travels outward from the chromosphere through the corona.

Solar flares travel

extremely quickly and last only a

few minutes

The Sun’s Effects on EarthThe tremendous amount of energy at the surface of the Sun produces a thin but steady stream of subatomic particles, or plasma. This constant flow of particles streaming out of the Sun’s surface in all directions is called the solar wind.

The solar wind is responsible for creating displays of green, yellow, and red light in the skies near Earth’s northern and southern regions.

In the northern hemisphere, these light displays are called the aurora borealis (the Northern Lights) and in the southern hemisphere, they are called the aurora australis (the Southern lights).

Auroras form as particles from the solar wind and are trapped by Earth’s magnetic field and are swept toward the North and South Poles. The

strength of the solar wind affects the shape and size of the aurora in these zones. Changes in the

solar wind make the aurora appear to be “dancing” in the night sky.

Many First Nations and Metis peoples understand that the Northern Lights are the spirits of family dancing in the night sky. The round dance is connected to the aurora. Many believe that when the round dance occurs, the Northern Lights are all around. Some Dene believe the Northern Lights provide them with the caribou and so were important for their survival.

Some Indigenous cultures of Saskatchewan also consider the Northern Lights to be very potent spirits or spirit dancers, who, if disrespected, may come down from the sky. First Nations and Metis peoples treat the night sky with respect and speak about it with great reverence and humility. Some Elders express a concern that many young First Nations and Metis peoples have lost their connection to the sacred night sky. They worry all the light pollution in towns and cities erodes our relationship with the land and our concept of night.

- Pearson Saskatchewan Science 9, p. 324

Episode 1: Secrets of the Sunhttp://www.youtube.com/watch?v=Zsz7ZTQAWRs

It is a fireball in the sky, a bubbling, boiling, kinetic sphere of white hot plasma, exploding and erupting. Its size is almost unimaginable--one million Earths would fit within its boundaries. In this violence is born almost all the energy that makes existence on Earth possible, yet, its full mysteries are only now beginning to be understood. From Sun spots to solar eclipses, solar flares to solar storms, the birth of the sun to its potential death, discover the science and history behind this celestial object that makes life on Earth exist