How Often Do the Planets Align? - Reference.com
www.reference.com › science › planets-align-4f495Apr 03, 2020 · Twitter. The nine planets in this solar system somewhat align once every 500 years and are grouped within 30 degrees every one to three alignments. When astrologers describe the planets as being aligned, they do not necessarily mean that all of the planets line up on a perfectly straight line. The last alignment within 30 degrees occurred in 561 B.C., and the next alignment within 30 degrees takes place in 2854.