Results 1 to 14 of 14

Thread: How common are 'naked eye' 5 planet conjunctions?

  1. #1
    Join Date
    Sep 2004
    Posts
    501

    How common are 'naked eye' 5 planet conjunctions?

    There was such a conjunction in 1953 BCE of the five naked eye planets how common is this type of event? How often does it occur?

    Thanks

  2. #2
    Join Date
    Jan 2008
    Posts
    698
    The first hit on my google search looks like a good paper on this.
    http://adsabs.harvard.edu/full/1994JBAA..104..293D

  3. #3
    Join Date
    Sep 2004
    Posts
    501
    Quote Originally Posted by glappkaeft View Post
    The first hit on my google search looks like a good paper on this.
    http://adsabs.harvard.edu/full/1994JBAA..104..293D
    Thanks very much for your aid

    I've noted an inconsistency



    It shows 5 march 1952 BCE and another source (well wikipedia)

    says:

    February 27, 1953 BC: A very close alignment of the naked-eye planets took place in which these planets are together in a span of 4.3 degrees.

    https://en.wikipedia.org/wiki/20th_century_BC

    What would be the cause of that?

  4. #4
    Join Date
    Jun 2003
    Location
    Central Florida.
    Posts
    6,028
    Does the BCE system correct for the missing Year Zero? The classic BC system did not.

  5. #5
    Join Date
    Sep 2020
    Posts
    25
    The question is how long to wait for the next time such a phenomenon? Apparently, not in our life. But the forecasts are interesting. I would like to observe this unique phenomenon.

  6. #6
    Join Date
    Aug 2005
    Location
    NEOTP Atlanta, GA
    Posts
    3,253
    Quote Originally Posted by Kay Burton View Post
    The question is how long to wait for the next time such a phenomenon? Apparently, not in our life. But the forecasts are interesting. I would like to observe this unique phenomenon.
    The linked article provides a table which lists past and future conjunctions. The next one is in September 2040. Iíll be 85 years old if I make it that long. YMMV.

  7. #7
    Join Date
    Jul 2005
    Posts
    19,626
    Quote Originally Posted by DonM435 View Post
    Does the BCE system correct for the missing Year Zero? The classic BC system did not.
    Common Era (CE) = Anno Domini (AD); Before Common Era (BCE) = Before Christ (BC).

    Grant Hutchison

  8. #8
    Join Date
    Jul 2005
    Posts
    19,626
    Quote Originally Posted by Hans View Post
    It shows 5 march 1952 BCE and another source (well wikipedia)

    says:

    February 27, 1953 BC: A very close alignment of the naked-eye planets took place in which these planets are together in a span of 4.3 degrees.
    The negative sign doesn't indicate years BCE; it's the astronomical year number. This numbering system includes a Year Zero, and so, while positive values are identical to CE years, the negative year numbers are one year different from BCE years. The presence of the negative sign lets you know that you're dealing with astronomical year numbers.

    ETA: For reference, this is actually stated on the first page of glappkaeft's linked article (top of the second column).

    Grant Hutchison
    Last edited by grant hutchison; 2020-Sep-24 at 03:43 PM.

  9. #9
    Join Date
    Jul 2005
    Posts
    19,626
    The -1952 Feb 27 quintuple cluster is distinguished by being the tightest in the six millennia Meis and Meeus analysed. The 2040 grouping is anaemic by comparison. But it does produce an alignment in which all five naked-eye planets, the moon and the sun lie within the same 30 degrees of ecliptic longitude, at about 0400UT, 2040 Sep 9. The sun is the outlier in this grouping, with the crescent moon sitting close to the planet cluster, so we have five planets and the moon within a 10-degree span.

    ETA: Here's the relevant diagram from Meeus's More Mathematical Astronomy Morsels. (As ever, click on the thumbnails to see the image.)
    2040 alignment.jpg

    Grant Hutchison
    Last edited by grant hutchison; 2020-Sep-24 at 03:39 PM.

  10. #10
    Join Date
    Jun 2003
    Location
    Central Florida.
    Posts
    6,028
    Quote Originally Posted by grant hutchison View Post
    Common Era (CE) = Anno Domini (AD); Before Common Era (BCE) = Before Christ (BC).

    Grant Hutchison
    So those CE tags mean exactly the same things as the older styling?

    I remember doing some term paper research on the University's book shelves back circa 1980 and seeing negative dates in historical articles, and the context made it clear that these were dates before A.D. 1. Makes sense, I guess, and loses cultural and religious baggage, but I haven't seen that style since.

    I figured that when the altered terminology was accepted, maybe they altered the BCE numbers to make the math easier.

  11. #11
    Join Date
    Jul 2005
    Posts
    19,626
    Quote Originally Posted by DonM435 View Post
    So those CE tags mean exactly the same things as the older styling?
    They do.
    The "Common Era" notation has actually been around for centuries, ever since Kepler used the Latin phrase Aerae Vulgaris instead of Anno Domini. And it's now more than three hundred years since "common era" dating was first used in English.

    So the CE/BCE notation is very much not (as people often seem to think) some new-fangled bit of "political correctness gone mad".

    Grant Hutchison

  12. #12
    Join Date
    Jun 2003
    Location
    Central Florida.
    Posts
    6,028
    Thanks for explaining that.

  13. #13
    Join Date
    Sep 2004
    Posts
    501
    Thanks for the all the many comments! Very helpful.

  14. #14
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,123
    I think the OP has been answered, and I throw this out mostly as a nuisance, but Vesta and Uranus are sometimes visible to the really sharp unaided eye. There must be much more frequent times when Mars, Vesta, Jupiter, Saturn, and Uranus are within a few degrees of each other.
    Forming opinions as we speak

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •