In corn, purple kernels (P) are dominant to yellow kernels (p). You have a plant with an unknown genotype that has a phenotype of purple kernels. You perform a testcross and find that all of the offspring are purple.
The layout of the solar system, including the Oort Cloud, on a logarithmic scale. Credit: NASA. In the furthest reaches of the Solar System is the Oort Cloud; a theorized cloud of icy objects that could orbit the Sun to a distance of 100,000 astronomical units, or 1.87 light-years away.
Keep in mind a light year is six trillion miles.) With the Oort cloud, estimates jump from 0.03 all the way to 3 Light years. The latter case is obviously a more extreme estimate. More likely, it's under one light year. All of this was radius, by the way, of the Solar System.