Earth Science
Earth in Space
Interior of the Sun
Study Tip
How would scientists use cameras to observe different layers of the Sun? Hint: Different temperatures are associated with different wavelengths on the electromagnetic spectrum!
The Sun
- The Sun is a sphere, composed almost entirely of the elements hydrogen and helium.
- The Sun is not solid, nor is it a typical gas.
- It does not have a defined outer boundary.
- It does have a definite internal structure with identifiable layers.
- Most atoms in the Sun exist as plasma.
- Fourth state of matter made up of superheated gas with a positive electrical charge.
Study Tip
How would scientists use cameras to observe different layers of the Sun? Hint: Different temperatures are associated with different wavelengths on the electromagnetic spectrum!
Internal Structure
From inward to outward, the layers of the Sun are:
- Central Core
- Plasma with a temperature is around 27 million ⁰C.
- At high temperatures hydrogen goes through nuclear fusion, which forms helium
- This energy moves outward, towards outer layers of the Sun.
- Radiative Zone
- Temperature of about 7 million ⁰C.
- Energy from core travels extremely slowly through here.
- Photons (particles of light) travel only a little before they hit another particle.
- The photon is absorbed and then released again.
- Convection Zone
- Hot material from near the radiative zone rises, cools at the Sun’s surface, and plunges back downward to the radiative zone.
- Convective movement helps to create solar flares and sunspots.
The Outer Layers
There are no solid layers to any part of the Sun’s atmosphere; these boundaries are fuzzy and indistinct.
- Photosphere
- The photosphere is relatively cool (6,700 ⁰C).
- Visible surface of the Sun.
- Region that emits sunlight.
- The photosphere has several different oranges, yellow and reds.
