Gloria Brand, age 13, of Victoria, BC , Canada, for her question:

How many miles does the earth travel in a day?

Every second, our world travels 18.5 miles along its 600 million mile orbit around the sun. In the same second it travels 170 miles on a vast cosmic journey through the milky way. In the same second it also whirls 1/86,400th part of a spin around its own axis.

It took scientists many centuries to chart this global whirligig. And it will be fun for you to figure out from the basic figures just how far the world and everything in it travels during a single day. There are, as you well know, 60 seconds in a minute, 60 minutes in an hour and 24 hours in a calendar day. So, multiply each of the mileages given above by 60 and by 60 and by 24 and you will have our global travel distance for a day.