There's still time to make travel plans for Aug. 21, when a total solar eclipse will cross the contiguous United States — the first such eclipse in 99 years. The total eclipse can only be witnessed within a 70-mile-wide path (called "the path of totality") which stretches from Oregon to South Carolina. According to author David Baron, it's "nature's most awesome show."

Baron should know: He's a self-professed "umbraphile," or eclipse chaser, who has followed them around the world. He's also a science writer who's written a suspenseful narrative history about the total solar eclipse that occurred in the summer of 1878.

Baron's book, American Eclipse, follows a group of 19th-century adventurers who raced out to the Rocky Mountains to study the eclipse up close. Thomas Edison, then 31, was part of this intrepid band; so was astronomy professor Maria Mitchell, who took some of her Vassar students out to Colorado to prove that women could "do science" too.

Baron vividly describes how, as the eclipse got underway, the temperature plummeted, nocturnal animals emerged from hiding and familiar colors of mountains and trees shifted. The total eclipse itself lasted about three minutes — the same span of time predicted for the upcoming Aug. 21 eclipse — but Baron makes those three minutes seem transcendent. Experiencing a total eclipse, he says, is "like falling through a trapdoor into a dimly lit, unrecognizable reality. ... The most prominent object is thoroughly foreign. You may know, intellectually, that is it both the sun and the moon, yet it looks like neither. It is an ebony pupil surrounded by a pearly iris. It is the eye of the cosmos."