Historically, the work is one of the earliest to employ the interplanetary theme. It is the first to portray a battle fought by space craft in the airless void; and possibly the first also to propose the use of sealed suits that enable men to traverse a vacuum. Of the more minor twists of plot initially found here that have since become parts of the "pulp" science-fiction writers' standard stock-in-trade, there are literally too many to mention.