The Sun

The Sun

Structure, Atmosphere, and Features

Interior of the Sun

• The Sun's Interior is composed of three main sections:

• Core

• Radiation Zone

• Convection Zone

The Core

• The Sun produces an A LOT of energy in the core through nuclear fusion

• Nuclear fusion occurs when HYDROGEN atoms combine to form HELIUM

• This process requires extremely high temperatures and pressure

The Radiation Zone

• The energy produced in the Sun's core moves outward through the radiation zone

• This is a region of very tightly packed gas where energy moves mainly in the form of electromagnetic radiation

• This zone is so dense that it can take over 100,000 years for the energy to move through it

The Convection Zone

• This is the outermost layer of the Sun's interior

• Hot gases rise from the bottom of the convection zone and slowly cool as they approach the top

• Cooler gases sink, forming loops of gas that move energy toward the Sun's surface

Multiple Choice

What layer of the Sun's interior produces the energy?

• Convection Zone

• Core

• Radiation Zone

• Corona

Multiple Choice

In the convection zone, ______ gas rises and ______ gas sinks.

• hotter, cooler

• cooler, hotter

Multiple Choice

The sun produces energy through what process?

• Fission

• Fusion

• Photovoltaic cells

• Photosynthesis

The Sun's Atmosphere

• The Sun's atmosphere is composed of three main sections:

• Photosphere

• Chromosphere

• Corona

The Photosphere

• Inner layer of the Sun's atmosphere

• This layer of gas is thick enough to be visible and is considered the surface layer

• When you look at an image of the Sun, you are looking at the photosphere

The Chromosphere

• Middle layer of the Sun's atmosphere

• This layer is seen as a reddish glow around the photosphere

• Can only be seen at the start and end of a total eclipse

• The Greek word chroma means "color" so the chromosphere is really the "color sphere"

The Corona

• Outer layer of the Sun's atmosphere

• Looks like a white halo around the sun

• Only seen during an eclipse

• Extends into space for millions of kilometers

• Corona means "the crown" in Latin

Multiple Choice

Which layer of the Sun's atmosphere is only seen at the beginning and end of an eclipse?

• Photosphere

• Corona

• Chromosphere

• Radiation Zone

Features of the Sun

• Sunspots

• Prominences

• Solar flares

• Solar wind

Sunspots

• Areas of gas on the Sun's surface that are colder than the gases around them

• Colder gases don't give off as much light

• Can be larger than the Earth

• The # of sunspots varies in a regular cycle, with the most appearing about once every 11 years

Prominences

• Huge loops of gas that often link different parts of sunspot regions

• These loops of gas are anchored to the photosphere and extend to the corona

• Can last for months

Solar Flare

• A release of magnetic energy that heats gas in the Sun's atmosphere and causes an eruption into space

• Typically lasts for a few minutes

Solar Winds

• Streams of electrical particles from the Sun

• Solar flares can increase the amount of particles

• Earth's magnetic field blocks the majority of solar winds except on the North and South Poles

Solar Winds cont.

• At the poles, the particles create electric currents that cause gas in the atmosphere to glow (Aurora Borealis a.ka. Northern Lights)

• Worst case scenarios: too many particles entering the atmosphere can cause magnetic storms and blackouts

Multiple Choice

Large eruptions of heated gas from the Sun's surface are called

• Prominences

• Solar winds

• Sunspots

• Solar flares

Multiple Choice

The corona sends out a stream electrical particles called the

• Solar flares

• Solar winds

• Sunspots

• Prominences