Fictional planets of the Solar System while yet others are purely fictional and were never intended as serious hypotheses about the structure of the Solar System. Vulcan was a hypothetical planet supposed to revolve around the Sun inside the orbit of Mercury, invoked to explain certain irregularities in Mercury's orbit. The planet was proposed as a hypothesis in 1859, and abandoned not later than 1915. The name "Vulcan" has been used for various other fictional planets, in and out of the Solar System, that do not correspond to the hypothetical planet Vulcan. The planet Vulcan in the "Star Trek" franchise, for instance, is specified as orbiting
Solar eclipses on the Moon Earth rotates nearly 24 hours, but its position at the sky is only in one position as it never changes as it does with some other moons (or satellites) in other planets or dwarf planets and a few asteroids even inside the solar system but are very rare in the outer part of the solar system. The last solar eclipse on the Moon was a total eclipse on July 27, 2018, with the whole Nearside and the tiny surroundings of the Farside seeing totality. Unlike the Earth which sees its eclipse for up to 2 1/2 hours the longest in