Small Solar System body possess some internal structure related to perturbations by the major planets (particularly Jupiter and Neptune, respectively), and have fairly loosely defined boundaries. Other areas of the Solar System also encompass small bodies in smaller concentrations. These include the near-Earth asteroids, centaurs, comets, and scattered disc objects. Small Solar System body A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be
Vulcan (hypothetical planet) circular orbits of Venus and Earth. Einstein's theory was empirically verified during the solar eclipse of May 29, 1919 by measuring the bending of sunlight. Astronomers generally quickly accepted that a large planet inside the orbit of Mercury could not exist, given the corrected equation of gravity. Observing a planet inside the orbit of Mercury is difficult, since the telescope must be pointed very close to the Sun, where the sky is only dark during a solar eclipse. Also, an error in pointing the telescope can result in damage for the optics, and injury to the observer if viewing directly.