As seen from the Earth, a planet will be in opposition with the Earth when its distance to the Earth is at a minimum. The term opposition also can mean that the planet is 180 degrees away from the Sun as seen from the Earth. A conjunction is simply the close encounter on the sky of two bodies. When two planets appear to be close together in the sky, such as Jupiter and Saturn every 20 years, they are said to be in conjunction. A planet can be in conjunction with the Sun, making it unobservable in the bright glare of the Sun.