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.
