Stephen Proulx, age 9, of Coventry, Rhode Island, for his question:

Is the sun completely round?

The sun and the moon, the planets and the stars all look like perfectly round balls. Some of these heavenly bodies can be measured in fine details. Then, almost always, we learn that this one or that one is not a perfect ball. Even our solid earth is slightly flattened at its poles, and a little wider around the equator.

The experts have tried and tried to measure the sun to see whether it is a perfect round. Some suspect that, like the earth, it is slightly wide around the waist and slightly flattened at the poles. Others think that the sun's equator may be narrower and the distance from pole to pole is slightly longer. But nobody is completely sure. All we can say is that the sun is a ball and the distance through the middle is about 865,000 miles, give or take 100 miles or so. It may be a perfect round or it may not.