All seven major planets form a kind of parade in the sky at the end of February. Although two of the planets are not visible to the unaided eye, all are on the same side of the sun during the evening hours. This planetary grouping happens when the planets appear to line up in the night sky as seen from Earth. They do not form a straight line, but they do stretch across the evening sky this year. The American space agency, NASA, says these astronomical gatherings are common. A parade of four or five planets visible to the unaided eye happens every few years. A similar parade took place last June, but only two planets could be seen without the use of special equipment. Six planets were visible in January. Four were visible to the unaided eye. In recent weeks, Mercury joined the group. Venus, Mars and Jupiter are all easily visible in the evening. Saturn is now very close to the setting sun and Mercury is close to the horizon, making both hard to see. Uranus and Neptune are the most distant planets. Uranus can be glimpsed with binoculars or a telescope under good conditions. But Neptune is now too close to the sun to be seen.