Fred Russo, age 13, of Glendale, Arizona for his question:

What is the photosphere?

The word photosphere means a glorious ball of light. The biggest, most glorious ball of light near our earth is the sun and astronomers use the word photosphere to describe its radiant face. If it were not for the glorious face of the sun, our earth would be a dark and frozen planet without life.

The photosphere is the surface of the sun. The surface, however, is not solid like the face of the earth, for the sun is so hot that all its elements are in a gaseous form. Above the photosphere is the chromosphere, a thinner layer of gases which corresponds to an atmosphere, Beyond the chromosphere extends the sun's pale, pearly corona. This is a still thinner layer of gases which reaches out into space like a halo.

The sun, like all heavenly bodies, rotates on its axis, We know for sure that the photosphere is not solid because of observations about the sun's rotation. The solid earth rotates altogether in one piece. The surface of the sun rotates faster at the equator than at the poles.  At its equator, the sun rotates once in about 25 days. At latitudes 45 degrees north and south of the equator, each rotation takes about 27 days. At latitudes 80 degrees north and south each rotation takes about 33 days.

Of course, no sensible person would look directly at the radiant face of the sun. It is even more dangerous to look directly at the sun through a telescope which makes light rays more intense, If a bit of paper is placed over the eyepiece of a telescope which is directly trained at the sun, it will catch fire and burn to a crisp. This intense light would be fatal to the human eye. Astronomers study the sun by shadow‑making instruments, by spectroscopes and from photographs.

You might suppose that our glorious sun had a perfect complexion, that its light‑giving photosphere was without blemish. But this is far from true, Solar photographs show that the sun's complexion is a heaving mass of ups and downs, somewhat like the waves of the ocean. Its seething gases are in constant turmoil.

In addition to this bumpy skin, the face of the sun is prone to rashes. We call them sunspots and some experts believe them to be solar storms. One of these sunspots may be large enough to swallow the earth a thousand times. The photosphere may break out in a rash of two or three of these giant pimples plus a few smaller ones,

The photosphere is estimated to be at a seething temperature of about 11,000 degrees Fahrenheit. However, this is cool compared with the heat in the heart of the sun. This, we think, is where Old Sol builds up his atomic power. The tremendous energy from this atomic furnace pours from the sun in all directions, day and night.

From every square yard of the photosphere enough energy pours forth to drive 700 family cars, About two parts in a billion parts of the sun's total output of energy falls upon this planet of ours. It provides most of our light and heat, and without it no living thing could. exist.