Look into the night sky just after sunset this Saturday and you could see a rare celestial event. Six planets — Venus, Mercury, Saturn, Neptune, Uranus and Jupiter — will align, creating a sort of “planet parade” across the western and southern sky.
Planetary alignments occur because all the planets in the solar system orbit the Sun along the same plane, called the ecliptic. Occasionally, their orbits bring them into nearly a perfect line from our perspective on Earth, even though the planets are not actually lined up in space.
Four of the planets on Saturday night — Saturn, Venus, Mercury, and Neptune — will form a cluster low on the western horizon. Saturn and Venus will be easy to detect with the naked eye, Mercury will be much dimmer, while Neptune is only likely to be seen with a telescope…