Cathy and Susan Chapman, age 12, of Winnipeg, Manitoba, Canada, for their question:

Does the Earth's rotation move the atmosphere?

The air seems to be made of filmy nothing, but its gases have weight, and the Earth's total atmosphere weighs many millions of tons. This heavy blanket of gases is hugged to the globe by the Earth's gravity. But gases act like liquids, flowing and blowing this way and that, and the slightest shove sets them off in a different direction. In addition to the downward pull of gravity, the atmosphere also feels the whirling spin of the Earth's rotation.

The atmosphere is hugged close to the spinning Earth, but rotation gives a twist to its blowing air. This makes a difference to the direction in which the blowing winds are twisted. It causes the prevailing winds blowing from the north and south to veer a little or deflect to the East or the west.