Planetary alignment occurs when planets in our solar system line up in a straight line or close to it from the perspective of Earth. This phenomenon can happen with any of the eight major planets, including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Alignments can be partial or full, depending on the positions of the planets in their orbits. These alignments are relatively rare and can last for a few days to several weeks. While they are visually striking, they do not have significant gravitational effects on Earth. However, they can be an exciting event for astronomers and skywatchers alike.