When was the last time all 9 planets were aligned?
When was the last time all the planets were aligned and approximately when will they be aligned again?
When astrologers speak of the planets being aligned (something which doesn't really concern astronomers) they don't mean that the planets will actually all lie on a straight line at some instant of time. One calculation of alignments within around thirty degrees (about as close as they can get) shows that the last such alignment was in 561 BC, and the next will be in 2854. All nine planets are somewhat aligned every 500 years, and are grouped within 30 degrees every 1 to 3 alignments.
If you'd like to read more, here's my source: National Solar Observatory Sacramento Peak page on planetary alignments.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.
This page has been accessed 106697 times since September 12, 2002.
Last modified: September 22, 2002 2:23:17 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)