Resonance
Resonance happens when any two periods have a simple numerical ratio. The most fundamental period for an object in the Solar System is its orbital period, and orbital resonances pervade the Solar System. In 1867, the American astronomer Daniel Kirkwood noticed that asteroids in the asteroid belt are not randomly distributed. There were distinct gaps in the belt at locations that corresponded to resonances with Jupiter. For example, there were no asteroids at the 3:1 resonance – a distance of 2.5 AU – or at the 2:1 resonance at 3.3 AU (AU is the astronomical unit, or essentially the distance from sun to earth).
Another common form of resonance in the Solar System is spin–orbit resonance, where the period of spin (the time it takes the orbit 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 that keeps the far side of the Moon away from the Earth.
Read more about this topic: Stability Of The Solar System, Overview and Challenges
Famous quotes containing the word resonance:
“It is closing time in the gardens of the West and from now on an artist will be judged only by the resonance of his solitude or the quality of his despair.”
—Cyril Connolly (1903–1974)