Pat Smyth, age 10, of Richmond, Virginia., for his, question:

Do they know how stars and planets are formed?

The brainiest scholars have been trying to answer this question for at least 5000 years. But even modern astronomers cannot state definitely how our own solar system was formed. However, they have amassed a mountain of information on the subject. From this they form theories, or likely explanations. Not all of them agree with the same theory. But they do agree that other starry suns and planets were created in more or less the.same way as our own solar system.

First they had to learn the true size and shape of our own solar system. For thousands of years, astronomers did not know this. But patiently they kept accurate charts of how the heavenly bodies appear to move in the sky. However, they thought that everything in the universe moved around the earth every day. Then in 1512, the Polish astronomer Copernicus suggested that the planets revolve around the sun. Finally, other astronomers proved this to be true. It was necessary to know what our sun and its planets are really like before anyone could find the truth about how they were created.

For thousands of years mankind wondered and guessed. By the 17th century, serious scholars knew enough to start on the problem of how solar systems really are born. In 1755, the German scholar, Emmanuel Kant, suggested that our sun and its planets condensed when an enormous cosmic cloud of gases started spinning and became hot. In 1796, the French scholar Laplace suggested that the original cosmic cloud was hot. From these two ideas came the Nebula Hypothesis, the theory that stars and planets form from enormous clouds of spinning gases.

This theory seems to fit the known facts. But in 1901, the English scholar James Jeans suggested that a passing star pulled huge streamers of material from our sun. Out in space, these swirling streamers cooled, condensed and became the solid planets. However, in the 1930s, astronomers proved that this so called Tidal Theory was impossible.

Nowadays, the most popular theory is the Nebula Hypothesis. Astronomers know a great deal about our Solar System and the universe. All the facts seem to agree that at least our starry sun and its family of planets formed from an enormous cloud of gases.

The evidence suggests that this started more than five billion years ago, when mysterious forces made the filmy gases condense and form a huge mass in the middle. Other mysterious forces made the shrinking cloud spin around like a wheel. The sun formed in the center. Around it, circles of thinner material condensed and formed the solid, orbiting planets.

Astronomers know of countless stars like our sun. If our solar system formed from a vast cloud of cosmic gases, then maybe they did too. If this is really so, then perhaps many or most of them also formed planets in the same way. But at present, this Nebula Hypothesis is still a theory, a likely explanation based on a lot of known facts. We need more evidence to prove it to be true    or untrue.