Still slogging along through the HIPPARCOS catalog – every day, I work through a dozen or so stars (and find myself wishing I had just written a C program for this already). At the moment I seem to have gotten through 276 entries in the database, out of a total of 327 reaching to the ten-parsec radius. Out of those stars, 23 have at least one planet with a complex biosphere, and at least a few systems have two each. It’s looking like a trend of about one in ten to twelve stars will have a more-or-less-Earthlike. I’m not bothering to count the “pre-garden” worlds, with liquid-water oceans but too young to have developed a post-Cambrian biosphere. There are quite a few of those.

Today I sat down for a few hours and started drawing a map of nearby space, including all stars of K class and above, and those few M-class stars that have Earthlike worlds. I’m using the same techniques that I once applied to this map of the solar neighborhood, and I imagine the end result will look similar.

I’m using a galactic coordinate system this time, rather than the usual equatorial coordinates, so a lot of stars will look like they’re in the wrong place if you’re accustomed to the maps from (e.g.) the 2300 AD or Universe tabletop games. I’m planning to include the appropriate coordinate transform in the Architect of Worlds draft, when I get around to writing the “using real astronomical data” section.

I’m also marking down tentative names for Earthlike worlds, instead of an abstract “resource value.” My vision for the Human Destiny setting has evolved quite a bit over the past few years. Today I’m assuming that the dominant interstellar civilizations won’t spend all that much time or effort exploiting star systems that don’t host complex biospheres. So the systems of greatest interest are going to be the ones that humans (eventually) settle.

If anyone’s interested in glancing at the work in progress, here’s a link to the appropriate entry in my Scraps folder. Only about twenty or so stars placed so far, or a little under one-third of the way through my data set. This is slow work, but it’s starting to come together.

Meanwhile, I’ve been working on a revision to my old notes about the density and structure of interstellar civilizations. Here’s a link to an article I wrote a few years ago, which lays out an argument about the limits to an interstellar civilization’s growth. (That article is also one of my few contributions to Winchell Chung’s Atomic Rockets website, in fact.) The Human Destiny setting incorporates that notion into its basic assumptions. I’ll probably publish those notes here within a few days.