The Sparrow is 400 pages and spans nearly fifty years. On trial in Rome, disgraced priest Emilio Sandoz narrates in flashback the events that led up to the Stella Maris crew assembling, reaching Rakhat, and making contact with the alien species (plural) there. We the audience have to learn about the Runa and Jana’ata as quickly and exhaustively as the crew does; on Earth, there’s the Jesuits and the mafia to contend with.
To try and cram this into a two-hour movie—even stretching it to three hours—would necessarily cut key developments. Since The Sparrow is headed for television, however, each episode could be bookended by the frail Sandoz trying to make his peers understand why he made the decisions he did. Each season could be the standard twelve episodes with a year in-between.
The Runa and Jana’ata wouldn’t suffer, either, since there could be entire episodes devoted to characters like the merchant Supaari VaGayjur. Consider the Battlestar Galactica season 2 episode “Downloaded,” where for the first time we see what happens to Cylons after they die. Suddenly, Number Six went from a sex symbol and saboteur to almost human. Most importantly, parsing out Sandoz’s story over the course of a season or two would preserve the horror of the novel’s emotional payoff.