Alison Gyves, age 10, of Tucson, Ariz.) for her question:

HOW DOES LIGHTNING DIFFER FROM HEAT LIGHTNING?

Lightning and heat lightning are the same. The thing that makes them seem different is where you happen to be. We see streaks of ordinary lightning when a storm is overhead or almost overhead. We are close enough to see the fiery flash as it darts down through the cloud. But sometimes the storm is miles away   too far for us to see its fiery streaks of lightning, but not far enough for the cloud to be hidden below the horizon.

This is when we see the bright, hazy blur of heat lightning. Actually the lightning flashes as usual  but all we see is the foggy light it spreads through the misty cloud. Usually we see heat lightning on a sultry evening, when the air longs to be cooled by a shower. But the storm that could cool things off passed us by and happened way off in the distance.