Starship Asterisk*

Posted: **Mon Mar 10, 2008 11:06 am**

Today's APoD - http://antwrp.gsfc.nasa.gov/apod/ap080310.html - got me wondering: when will we have another alignment like the one linked to in the description, with the words planetary - http://antwrp.gsfc.nasa.gov/apod/ap020510.html, and conjunctions - http://antwrp.gsfc.nasa.gov/apod/ap020429.html..?
My guess is that since that one just occured recently (six years ago), we won't see one like it again for a while, given the orbits of some of the planets. (Which is sad - for me - since my interest in astronomy began the following year.....

)
Anyway, anyone know when this may happen again, or care to point me in the direction of where I could find this info? Thanks in advance.

Posted: **Mon Mar 10, 2008 9:25 pm**

Indigo_Sunrise wrote: Anyway, anyone know when this may happen again, or care to point me in the direction of where I could find this info? Thanks in advance.

Since the synodic rotation period of Venus is 583.92 days and the synodic rotation period of Mercury is 115.88 days, it would not escape your notice that Tsyn of Venus is about 5 times Tsyn of Mercury. Just wait 583 days for the next similar conjunction between Venus and Mercury.

Regards,
Henk

Posted: **Tue Mar 11, 2008 4:30 pm**

Thanks, Henk. And apologies for not being more clear. While I understand that Venus and Mercury will align more frequently, as their orbits are considerably shorter, I was meaning an alignment of the naked eye planets, (Mercury, Venus, Mars, Saturn, Jupiter), as were shown in the second and third links I included.
I was mostly just wondering if something like that would be occurring again in my lifetime, since at the time those images were taken (2002), I wasn't the avid amateur astronomer that I am today. (Cool alliteration!) 8)

Anyway, sorry for the confusion, and I'll keep chasing down any info on that particular subject.

Posted: **Tue Mar 11, 2008 10:17 pm**

Indigo_Sunrise wrote:I was meaning an alignment of the naked eye planets, (Mercury, Venus, Mars, Saturn, Jupiter), as were shown in the second and third links I included.
I was mostly just wondering if something like that would be occurring again in my lifetime

No problem. Since you want a conjunction between outer and inner planets, the outer planets must align at the opposite site of the sun.
What matters, are the synodic times:
Mercury: 115.88
Venus: 583.92
Mars: 779.94
Jupiter 398.88
Saturn: 378.09

When Saturn and Jupiter are in conjunction, it will take another 16 years for another conjunction with Saturn. Try solving the equations:

J * 398.88 = S * 378.09 = M * 779.94 = V * 583.92 = Y * 115.88
while J, S, M, V and Y are integers. Y = 5V.

The equation may not precisely met for V, since multiple instances of the position of Venus give the same position between the stars. So solving the first three parts for Saturn, Jupiter and Mars is more important.

I do not know the answer, just giving you a possible hint for finding your own solution.

Yet another hint: there are many 'planetary' programs on the net for doing simulations. Under Debian and KDE i use e.g. Kstars. For windows there is Celestia (know it by name, not using it). If you can find the old DOS version of Skyglobe, that might do the trick as well.

Regards,
Henk

Posted: **Wed Mar 12, 2008 3:33 am**

Indigo_Sunrise wrote:Thanks, Henk. And apologies for not being more clear. While I understand that Venus and Mercury will align more frequently, as their orbits are considerably shorter, I was meaning an alignment of the naked eye planets, (Mercury, Venus, Mars, Saturn, Jupiter), as were shown in the second and third links I included.
I was mostly just wondering if something like that would be occurring again in my lifetime, since at the time those images were taken (2002), I wasn't the avid amateur astronomer that I am today. (Cool alliteration!) 8)

Anyway, sorry for the confusion, and I'll keep chasing down any info on that particular subject.

--------------------------------------------------
The 2002 sunset view from Maricopa, Arizona of the 5 planets is rare:
http://antwrp.gsfc.nasa.gov/apod/ap020510.html

Code: Select all

Fri 2002 May 3 19:00

              Right                   Distance    From 33°N 0°W:
            Ascension    Declination      (AU)   Altitude Azimuth
Sun          2h 42m 47s   +15° 47.2'     1.008    -4.109  111.831 Set
.
Mercury      4h  5m 42s   +23° 32.3'     0.855    16.467  107.734 Up
Venus        4h 31m 54s   +22° 47.6'     1.460    21.394  103.987 Up
Saturn       4h 50m 32s   +21°  7.0'     9.903    24.431  100.184 Up
Mars         4h 48m 19s   +23° 15.9'     2.360    24.961  102.545 Up
Jupiter      6h 49m 33s   +23°  9.9'     5.676    50.160   87.354 Up

--------------------------------------------------
However, this August you can sunset view a clustering of all 5 planets
except that they will be much lower in the sky (in altitude)
and Jupiter will be to your back:

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Fri 2008 Aug 15 19:01
http://www.fourmilab.ch/cgi-bin/Solar

              Right                   Distance    From 33°N 0°W:
            Ascension    Declination      (AU)   Altitude Azimuth
Sun          9h 42m 31s   +13° 45.2'     1.013    -4.077  109.297 Set
.
Mercury     10h 45m 37s    +8° 59.1'     1.282     6.145   96.741 Up
Saturn      10h 46m 49s    +9° 32.7'    10.295     6.697   97.055 Up
Venus       10h 55m  4s    +8° 26.6'     1.604     7.826   95.018 Up
Mars        11h 52m 36s    +1° 31.3'     2.354    16.097   81.116 Up
.
Jupiter     18h 58m 18s   -23°  2.1'     4.346    24.928  -35.281 Up

--------------------------------------------------
If you are willing to travel to around the Tropic of Capricorn in the
Southern Hemisphere these planets will be much higher in the sky
(though not as high as in 2002):

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Fri 2008 Aug 15 17:58
http://www.fourmilab.ch/cgi-bin/Solar

              Right                   Distance    From 23°30'S 0°W:
            Ascension    Declination      (AU)   Altitude Azimuth
Sun          9h 42m 21s   +13° 46.0'     1.013    -4.076  103.248 Set
.
Mercury     10h 45m 21s    +9°  1.0'     1.283    11.919  105.453 Up
Saturn      10h 46m 48s    +9° 32.8'    10.295    12.004  106.102 Up
Venus       10h 54m 52s    +8° 27.9'     1.605    14.269  106.034 Up
Mars        11h 52m 30s    +1° 32.0'     2.354    30.190  106.662 Up
.
Jupiter     18h 58m 19s   -23°  2.1'     4.346    43.836  -79.979 Up

--------------------------------

Starship Asterisk*

Planetary alignments (APOD 10 Mar 2008)

Planetary alignments (APOD 10 Mar 2008)

Re: Planetary alignments