Hera was the site (via Serenity Valley) of what turned out to be the last major battle of Unification War. Hera is the breadbasket of the system. Lying between the Core and outer planets on a major shipping lane, Hera was a major strategic locus during the war. There are over half a million gravestones of those that lost their lives in the battle (from both sides), in the hills next to Serenity valley.

A civilized planet (or at least one with good medical facilities). It was also one of the first planets to be terraformed after the initial terra-forming of the core system. It has qutie some bigger cities and even a 'rich' population. There is Alliance control seen on this planet, as well as daily shipings from and to the core system. But as all border planets there are also large slum populations. One of the problems is that a lot of farmers moved to the city to find jobs after serveral years of dry spells and harsh weather, only to find themselves without a job.

Heinlein is a gas giant, and also where the system is named after. It's home to three moons, all terraformed.