Starseed

Starseeds are a mysterious alien life form. There is not much information available on them, as they are quite difficult to understand. These "seeds" are about a mile wide in diameter, and they float through the galaxy. It is said that they come from the core of the galaxy and float to other planets near its rim, before ejecting their "eggs" and returning to the galaxy's core. They are a unique lifeform in that they migrate and move using a biological solar sail.

Physical Description and Behavior
Star seeds normally exist in a smooth egg-shape about a mile in diameter and a mile and a half long. In this form they travel at around 80% of light speed through the galaxy, coasting on their momentum. Whenever they reach a star and need to make a course correction, the starseed unfolds itself - a thin reflective membrane a few millimeters thick but thousands of miles wide slowly unwraps itself layer by layer (the egg-shaped body is mostly this folded, compact sail). This sail is a parallelogram marked with a slight thickening of the membrane in a cross shape that is the starseed's main body and biomass. At the center of the compacted egg is a small bob of tissue that the sail normally enmeshes connected to the corners of the sail by thin, threadlike shrouds. This bob holds the starseed's egg for release at the edge of the galaxy and several central muscles for manipulating the shrouds and sail for attitude and thrust control.

Starseeds normally live in the galactic core, but migrate to the edge of the galaxy as part of their reproduction. After fertilization in the core, the starseeds navigate their way out to the rim where they release their eggs. Most are left to hatch into infants who later migrate to the galactic core, but many scientists speculate that some seeds are cast out of the Milky Way altogether towards the various globular clusters orbiting it and towards the Andromeda Galaxy, possibly colonizing and seeding them with life as well. Given that average starseeds travel at approximately 80% lightspeed, this migration can easily take over a hundred thousand years for a round-trip even for healthy adults.

Starseeds and Known Space
Eventually it was discovered that starseeds are actually ejecting microorganisms on these planets in order to create new life in a form of panspermia, hence the term "starseed". A super advanced alien race called the Outsiders track down starseeds because once a planet is seeded with life, new races are created and they in turn become customers of the Outsiders. However, it is unclear whether or not the Outsiders actually create the starseeds themselves.

The Pierson's Puppeteers say that they have created a technology called a starseed lure. As made obvious by its name, it attracts starseeds towards a certain planetary system or planet. It is said that they used a starseed lure to attract starseeds, and by extension, Outsiders, to a human colony. Since they manipulated many of the events in the history of the human race, it is a possibility that this could have been a large factor in the result of the Man-Kzin war, since the technology needed by the humans to win that war was obtained from the Outsiders during that particular visit.

Behind the scenes

 * Starseed origins were revealed in Niven's novel Peace and Freedom.
 * Neutron Star [Ch. Grendel], Niven, L., 1968 Del Rey, Ballantine Books, New York