According to researchers at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), a joint institute of Stanford University and the SLAC National Accelerator
Laboratory the nomad planets could be surprisingly common in our bustling galaxy. The study predicts that there may be 100,000 times more of these wandering, homeless planets than stars in the Milky Way. If this is the case, these intriguing cosmic bodies would belong to a whole new class of alien worlds, shaking up existing theories of planet formation. These free-flying planets may also raise new and tantalizing questions in the search for life beyond Earth. According to researchers and while nomad planets cannot benefit from the heat given off from their parent stars, these worlds could generate heat from tectonic activity or internal radioactive decay. For now, characteristics of these foreign objects are still unknown, they could be icy bodies, similar to other objects found in the outer solar system, rocky like asteroids, or gas giants similar to the most massive planets in our solar system. The researchers used a technique called gravitational microlensing to detect these homeless planets. This method examines the effects of a massive object passing in front of a star. The researchers are hopeful that follow-up observations using next generation telescopes, particularly of the smaller objects, will yield more detailed results. The planned space-based Wide Field Infrared Survey Telescope, and the Large Synoptic Survey Telescope on the ground, are both set to begin operations in the early 2020s.