Night sky or good binoculars, the planets appear as discs demonstrating finite size, and it is possible to observe orbiting moons which cast shadows onto the host planet's surface. Venus is the most prominent planet, often called the "morning star" or "evening star" because it is brighter than the stars and often the only "star" visible near sunrise or sunset, depending on its location in its orbit. Mercury, Mars, Jupiter and Saturn are also visible to the naked eye. Earth's Moon is a grey disc in the sky with cratering visible to the naked eye. It spans, depending on its exact location,
Star cluster be accounted for when using this method. Nearly all stars in the Galactic field, including the Sun, were initially born in regions with embedded clusters that disintegrated. This means that properties of stars and planetary systems may have been affected by early clustered environments. This appears to be the case for our own solar system, in which chemical abundances point to the effects of a supernova from a nearby star early in our solar system's history. In 1979, the International Astronomical Union's 17th general assembly recommended that newly discovered star clusters, open or globular, within the Galaxy have designations following