Fictional planets of the Solar System 40 Eridani A. Counter-Earth was a hypothetical planet sharing an orbit with Earth, but on the opposite side of the Sun (hence Earth and Counter-Earth would always be invisible to each other). The idea of a counter-Earth has never been a serious scientific hypothesis in modern times. Phaëton is a name given to a supposed planet existing in the past between the orbits of Mars and Jupiter, which no longer exists, having become the Solar System's asteroid belt. Proposed not long after the discovery of multiple asteroids at the beginning of the 19th century, the idea that the asteroids were
Solar energy use in rural Africa In the article by Burney et al. (2010) another use for solar energy that has been proposed is the Photovoltaic- (or solar-) powered drip irrigation (PVDI) system [which] combines the efficiency of drip irrigation with the reliability of a solar-powered water pump… [Where the] PV array powers a pump (either surface or submersible, depending on the water source) that feeds water to a reservoir. The reservoir then gravity-distributes the water to a low-pressure drip irrigation system. No batteries are used in the system: The pump only runs during the daytime, and energy storage is in the height of the column