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 hot water in Australia from 01/10 2007 to 30/06 2009, offered all house owners in NSW a rebate on systems that were replacing existing electric hot water systems. The more efficient the system (emitting less Greenhouse gas), the more RECs the system was eligible for, generating a higher rebate. Power and Water Corporation, the principal water and electricity supplier in the Northern Territory, offers an REC buyback scheme on installations of solar water heaters. The buyback must be applied for and assigned less than one year after the installation. The Queensland Government's Solar hot water rebate scheme finished on 30 June 2005. No state