Q: How far did the recent eclipse travel from the coast, and what determines how far it goes?

—Richard Morris, Newnan

A: The NASA map tracking the 2017 August eclipse ends in the North Atlantic Ocean, thousands of miles from shore, off the coast of west Africa, around 7 degrees north latitude and 27 degrees west longitude. But the eclipse began east of the International Date Line in the North Pacific Ocean, around 39 degrees north and 171 degrees west.

“The shape of an eclipse track depends on how much of the moon’s shadow touches down on the earth and where it touches down as the moon orbits around us. That varies from eclipse to eclipse,” Larry Marschall, deputy press officer for the American Astronomical Society and emeritus professor of physics at Gettysburg College, told Q&A on the News.

For instance, if the eclipse occurs when the moon is pretty far north, the shadow may just graze the earth near the North Pole, and the track will be short, he wrote. If the eclipse occurs when the moon is closer to the equator, as it was in August, he says the path will be long, covering nearly half the circumference of the earth.

Fast Copy News Service wrote this column. Do you have a question? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).