The temperature of the sun is over 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than 1600 million degrees at the centre .The sun is also much hotter than the Earth that matter exist only as a gas , except at the core .In the core of the sun , the pressure is so great against the gases that ,despite the high temperature ,there may be a small solid core .However no one really knows since the centre of the Sun can never be directly observed .
Solar astronomers do not know that the sun is divided into five layers or zones .Starting at the outside and going down into the sun ,the zones are the corona chromosphere ,photosphere ,convection zone and finally the core .The first three zones are regarded as the sun’s atmosphere .But since the sun has no solid surface ,it is hard to tell where the atmosphere ends and the main body of the sun begins .
The Sun’s outermost layer begins about 10,000 miles above the visible surface and can be seen during an eclipse such as the in February 1979 and goes outward for millions of miles.
The corona is brilliant, pearly white, filmy light about as bright as the full Moon. Its beautiful rays are a sensational sight during an eclipse. The corona’s rays flash out in a brilliant fan that has wispy spike like rays near the Sun’s north and south poles. The corona is thickest at the sun’s equator.
The corona rays are made up of gases straming outward at tremendous speeds and reaching a temperature pf more than 2 million degrees Fahrenheit. The rays of gas thin out as they reach the space round the planets. By the time the Sun’s corona rays reach the Earth, they are weak and invisible.
a) Why is there a small solid core in the sun?
b) How many zones is the sun divided into ? Explain ?
c) Give a vivid description of the outer appearance of the corona.
d) Why are the rays of the sun weak when they reach the Earth?
e) The paragraphs following the passage most likely discuss which of the following?
A) The remaining layers of the Sun form.
B) The evolution of the Sun to its present.
C) The eclipse of February 1979
D) The scientists who study astronomy.
f) Write a precis on the passage above and provide a suitable title.