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We present 230 realizations of a numerical model of planet formation insystems without gas giants. These represent a scenario in which protoplanetsgrow in a region of a circumstellar disk where water ice condenses (the "iceline''), but fail to accrete massive gas envelopes before the gaseous disk isdispersed. Each simulation consists of a small number of gravitationallyinteracting oligarchs and a much larger number of small bodies that representthe natal disk of planetesimals. We investigate systems with varying initialnumber of oligarchs, oligarch spacing, location of the ice line, total mass inthe ice line, and oligarch mean density. Systems become chaotic in ~1 Myr butsettle into stable configurations in 10-100 Myr. We find: (1) runs consistentlyproduce a 5-9 Earth mass planet at a semimajor axis of 0.25-0.6 times theposition of the ice line, (2) the distribution of planets' orbitaleccentricities is distinct from, and skewed toward lower values than theobserved distribution of (giant) exoplanet orbits, (3) inner systems of twodominant planets (e.g., Earth and Venus) are not stable or do not form becauseof the gravitational influence of the innermost icy planet. The planetspredicted by our model are unlikely to be detected by current Dopplerobservations. Microlensing is currently sensitive to the most massive planetsfound in our simulations. A scenario where up to 60% of stars host systems suchas those we simulate is consistent with all the available data. We predictthat, if this scenario holds, the NASA Kepler spacecraft will detect about 120planets by two or more transits over the course of its 3.5 yr mission. Futuremicrolensing surveys will detect ~130 analogs over a 5 yr survey. Finally, theSpace Interferometry Mission (SIM-Lite) should be capable of detecting 96% ofthe innermost icy planets over the course of a 5 yr mission.

The Invisible Majority? Evolution and Detection of Outer Planetary Systems without Gas Giants