loomed         appeared dimly or vaguely as a large, threatening shape
rille               a long, narrow valley on the surface of the moon
runt               animal, person, ofr plant that is smaller than the usual size. If used about a person, runt is sometimes considered offensive.
staggered    moved or walked unsteadily; weary
summoning  stirring to action; rousing
taunted        jeered at; mocked; reproached
trench          any ditch; deep furrow
trudged       walked wearily or with effort


While daring each other to jump over rilles, or narrow valleys on the Moon, Gerry and Vern get into trouble. Vern falls and hurts his knee while also knocking his battery, which gives him air to breathe in his spacesuit, loose. Luckily, the boys are able to get to a nearby shelter wehre Vern is out of danger.