Susan Salbert, age 12, of Columbia, S, C,, for her question:

Could our man‑made satellites cause an eclipse?

The planets and the moons have long, tapering shadows pointing away from the sun and the biggest of them have the biggest shadows. We get a solar eclipse when the shadow of the moon falls upon part of the earth Then the moon is near enough to reach us with its shadow and directly between us and the sun. To cause an eclipse, a heavenly body must be the right size and the right distance away.

Our man‑made satellites also have shadows, but they are small objects with small shadows. What's more, they orbit high above the earth, too far away for their shadows to reach us. If one of them just happened to pass directly between your line of vision and the moon, you might see it as a small black dot. But it would be too small and too far away to cause an eclipse of the moon or of the sun.