that can have that can have dramatic dramatic

effects on the effects on the Earth and Earth and

other planetsother planets

Our Sun is a turbulent, active starOur Sun is a turbulent, active star

As the Sun turnsAs the Sun turns

Like the Earth, the Sun rotates. However, unlike the Earth, the Sun has a complex rotation mechanism.

What makes the Sun hot?

Fusion in the Sun’s core produces heat/energy

The Sun’s Roiling SurfaceThe Sun’s Roiling Surface

Like fudge or oatmeal cooking, the Sun’s surface boils up with heat, then crashes down

When these big columns of gas crash down, they generate sound waves inside the Sun. By tracking the speed and path of those sound waves, scientists can understand the inside of the Sun!

Size of Earth, for comparison

SunspotsSunspots

Sunspots denote regions of strong

magnetic fields. They appear dark because

they are relatively cooler than the surface.

The 11 year The 11 year sunspot cyclesunspot cycle

A regular cycle of sunspot numbers over the past 300 years.

The amount of magnetic activity on the Sun varies

in an 11 year cycle.

What causes solar activity?What causes solar activity?

Most sunspots and events on the Sun are caused by eruptions and tangles of complex magnetic fields

Seeing Magnetic Field Seeing Magnetic Field LinesLines

Plasma emission traces out magnetic

fields in the solar corona

Solar EruptionsSolar Eruptions

Solar prominence dwarfs Earth in size

Huge flare of 28 October 2003

Common during the Sun’s active periods

Explosions on the SunExplosions on the Sun(Coronal Mass Ejections)(Coronal Mass Ejections) A billion tons of hot gas

being launched from the Sun.

White circle in image indicates size and location of Sun, which is blocked by a metal disk in the instrument.

A solar “wind” streams into A solar “wind” streams into the solar system and shapes the solar system and shapes

Earth’s magnetosphereEarth’s magnetosphere

The Sun generates The Sun generates Space Weather in our Space Weather in our

solar systemsolar system

Solar activity can have a dramatic impact on communications, satellites, and astronauts.