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When will all the planets in our solar system be in alignment?

Date: Tue Feb 11 12:00:17 1997
Posted by: Ted Houle
Grade level: undergrad
School/Organization: Sault College
City: Sault Ste. Marie State/Province: Ontario
Country: Canada
Area of science: Astronomy
Message ID: 855684017.As


When will all the planets in our solar system be in alignment?

This question comes up every so often on the USENET newsgroups and in the news media as well. Since all the planets orbit the Sun with a given period, at some point they must all line up. For example, the Earth takes one year to go around the Sun, while Mars takes about two. That means every two years Mars and Earth will line up with the Sun. The more planets you want to align, however, the longer it takes for all of them to line up.

People seem to have heard that these alignments can cause earthquakes, huge tides, floods, etc. This is simply not true. I have written a special web page talking about this, as well as other common misconceptions in astronomy. Take a look at the page about alignments (which has links to other sites about them as well), or you can go to the Bad Astronomy front page.

©2008 Phil Plait. All Rights Reserved.

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