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Why does the sun shine?

The Sun shines because it sends out energy in all directions as radiation. This radiation takes the form of light and heat. Almost the same amount of radiation leaves the Sun in all directions. It takes about eight minutes for the light from the Sun to travel to the Earth.


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Why does the sun shine?

Like other stars, the Sun is made up mainly of hydrogen gas. The temperature at the Sun's surface is about 10,000 degrees F, but rises to about 27,000,000 degrees F at its core. The temperature and pressure...more

Why does the sun shine?

The energy made in nuclear reactions in the Sun's core travels outward through the Sun's intermediate layers. In the radiation zone, energy gradually travels outward as atoms repeatedly absorb and give...more

IMF

IMF stands for Interplanetary Magnetic Field. It is another name for the Sun's magnetic field. The Sun's magnetic field is huge! It goes beyond any of the planets. The Sun's magnetic field got its name...more

The Hydrogen Fusion Process

In the basic Hydrogen fusion cycle, four Hydrogen nuclei (protons) come together to make a Helium nucleus. This is the simple version of the story. There are actually electrons, neutrinos and photons involved...more

Fusion Inside the Stars

Fusion in the core of stars is reached when the density and temperature are high enough. There are different fusion cycles that occur in different phases of the life of a star. These different cycles make...more

The Neutron Capture Process

Neutron capture can occur when a neutron approaches a nucleus close enough for nuclear forces to be effective. The neutron is captured and forms a heavier isotope of the capturing element. When the new...more

The Supernova

A Supernova is a very massive star that explodes at the end of its life cycle. The supernova is the furnace where the heavy elements (heavier than iron) are formed. ...more

Fusion Reactions

Nuclear fusion is a process where two or more nuclei combine to form an element with a higher atomic number (more protons in the nucleus). Fusion is the reverse process of nuclear fission. Fusion reactions...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF