Stability of the Solar System essentially the distance from sun to earth). These are now known as the Kirkwood gaps. Some asteroids were later discovered to orbit in these gaps, but their orbits are unstable and they will eventually break out of the resonance due to close encounters with a major planet. Another common form of resonance in the Solar System is spin–orbit resonance, where the period of spin (the time it takes the planet or moon to rotate once about its axis) has a simple numerical relationship with its orbital period. An example is our own Moon, which is in a 1:1 spin–orbit resonance
Solar power in the United States per house." An innovative financing arrangement pioneered in Berkeley, California, and Palm Springs, lends money to a homeowner for a solar system, to be repaid via an additional tax assessment on the property for 20 years. This allows installation of the solar system at "relatively little up-front cost to the property owner." Now known as PACE, for Property Assessed Clean Energy, it is available in 28 states. Freddie Mac and Fannie Mae have objected to the repayment of solar loans being senior to mortgage loans, and some states have relegated PACE loans to junior loans. HR 2599 was introduced to