Grant Harvey, age 10, of Salt Lake City, Utah, for his question:

WHEN WILL OUR SUN EXPLODE?

A few years ago we were told to go outdoors to behold a brand‑new star called a nova. Actually, it was an old star that exploded ages ago‑‑and the news just arrived from outer space. Once in a great while, this sort of tragedy does happen later. But for this to happen, it must be a certain type of star. And our sun is not this type of star.

So it is not likely that our sun will explode, now or in the future. Scientists tell us that one day our sun will burn itself out‑‑but it has plenty of fuel to burn cheerfully for at least 5 billion years. So we can depend on our starry sun to behave nicely, just as it always has.