Download Layers of the Sun

Layers of the Sun
Let’s see how the energy of the Sun moves from its inner core to the outer regions of its atmosphere. The
CORE of the Sun is where energy is first formed. It is the first layer in the Sun’s interior. Its temperature is 27
million degrees Fahrenheit. Enormous amounts of helium are produced here through nuclear fusion. Nuclear
fusion is the process of combining two or more small nuclei to form a single, larger nucleus. Thus, creating a
helium atom, neutron and energy. From the core, energy moves outward toward the Sun’s surface and
surrounding atmosphere. The energy moves through several layers or zones. Remember the Sun’s layers are
made of hot gases and they not solid like the Earth’s layers.
The energy moves out from the core through the RADIATIVE ZONE. The radiation zone is a region of very
packed gas where energy moves mainly in the form of electromagnetic radiation. It can take energy up to 170
thousand years to move through the radiation zone. Scientists calculate the temperature to be cooler than
the core—it is only a 4.5 million degrees Fahrenheit. That’s HOT!
The Sun’s next layer is the CONVECTION ZONE. The convection zone is the outermost layer of the Sun’s
interior. Convection is how energy moves from the inner parts of the Sun to the outer part of the Sun that we
see. We can see convection when we look at a pot of boiling water. Convection is what makes large, slow
moving bubbles form in a pot hot boiling water. Through convection the heat moves from the bottom of the
pot to the surface where it is cooler. Hot gases rise and sink here. Convection is what happened when you
heat a bubble of gas. Hot gas is less dense, so it starts to float upward. Once is floats to the top, the hot
bubble cools down and begins to sink again. The rising and sinking is called convection. The loops formed by
sinking cool gas causes energy to move towards the Sun’s surface. The Sun’s convection zone is a bubbling 2
millions degrees Fahrenheit.
The PHOTOSPHERE, the Sun’s visible surface, is the first layer of the Sun’s atmosphere. The Sun does not have
a solid surface, but instead when you are looking at the Sun, you are looking at the “liquid-like” plasma. The
photosphere is considered to be the Sun’s boiling layer. The bubbling motion of the convection layer makes
the granular patterns we see on the photosphere. The granules may look small in pictures, but scientists
estimate they are really about the size of the Moon. SUNSPOTS—indicating giant magnetic storms—are also
visible on the photosphere. Most of the time sunspots come in pairs—like the poles of a magnet. Even though
sunspots are very, very hot they look darker than the rest of the Sun because they’re cooler. This layer of the
Sun has cooled off to 10,000 degrees Fahrenheit and the Sunspots are even cooler—about 7,800 degrees F.
Just above the photosphere is the CHROMOSPHERE with huge solar flares and loops of hot gases shooting up
thousands of miles. The chromosphere is the middle layer of the Sun’s atmosphere. This layer is visible during
a total solar eclipse. Things begin to heat up again here—the temperature is estimated to be 50,000 degrees
F. The Greek work chroma means color.
And above the chromosphere is the CORONA—we can only see it during a total solar eclipse as a rainbow
colored halo. The latin word “corona” means crown. The corona is very, very hot—4 million degrees F. It is
also very thin, only extending into space for millions of kilometers. Scientists are still trying to figure out why it
is hotter than other parts of the Sun. This is a big mystery…
Sometimes when the Sun is very active, the hot gases shooting out of the Sun are so powerful that they blow
away from the Sun into the solar system. They stream away in all direction from the Sun and can move up to 1
million miles per hour. These streaming, hot gases are called the SOLAR WIND.
SOLAR FLARES are sudden, bright outbursts of energy that happen as the Sun’s magnetic fields twist, tear and
reconnect.
CORONAL LOOPS are magnetic loops with strong magnetic fields.
Giant arches of gas that erupt on the Sun are called PROMINENCES. They can last several days.
CORONAL MASS EJECTIONS coming from the Sun have the most energy of all these solar events. Sometimes
they head toward the Earth where they can cause communications disruptions and damage satellites. We are
very lucky here on Earth because we have a powerful magnetic shield around us which protects us from
getting too much energy. Earth is the perfect home planet for us!
The Sun is a very dynamic and active star!
http://www.eyeonthesky.org/