How Did Ulysses Sail By The Stars?

[jcmannone]

In The Odyssey, Book V (by Homer 800BC) Ulysses is trying to get back home to Greece some 400 nm miles away (northeast) and his sailing directions from Ogygia (Malta) are given in celestial terms. (Due to mitigating circumstances, he ends up in Phaecia (Corfu) somewhat NW of his destination, Ithaca):

"Moreover, she made the wind fair and warm for him, and gladly did Ulysses spread his sail before it, while he sat and guided the raft skillfully by means of the rudder. He never closed his eyes, but kept them fixed on the Pleiads, on late-setting Bootes, and on the Bear- which men also call the wain, and which turns round and round where it is, facing Orion, and alone never dipping into the stream of Oceanus- for Calypso had told him to keep this to his left. Days seven and ten did he sail over the sea, and on the eighteenth the dim outlines of the mountains on the nearest part of the Phaeacian coast appeared, rising like a shield on the horizon."

These directions sound easy, but they are not. I tried it with some planetarium software, but got a little confused on following the goddess''s instructions. I''m trying to get a better feel on how he navigated the stars (remember, Polaris is nowhere near the North due to Earth''s precession). Any comments? (This is not a test!)

Thanks,
JCM

[928frenzy]

The variation of Polaris'' position in 3000 years has not changed that much. Thus Ulysses (a fictional character in a book of mythology) could have used Polaris as a guiding star.

~ Happy sails to you ~ _/) ~

[jcmannone]

I beg to differ. Earth’s spin axis wobbles due to the presence of the Moon and the Sun. It traces out a circle against the background stars about every 26,000 years. Only in recent times is Polaris the “North Star”. It will be closest to North in around another 125 years or so. I have tabulated the azimuth of Polaris from my location (36N 85W) for Jan 1 11:17 PM EST (an arbitrary place in the Northern Hemisphere and arbitrary time):

2200 AD 000 deg 45.822’
2100 000 4.070’
2003 359 23.898’
1000 352 22.039’
1 345 39.494’
1000 BC 339 10.097’

As you can see, significant variations occurred within the last millennium and were very serious at Homer’s time.

Though the poem is mythological, it does reflect a truth about the challenges of celestial navigation around that time period.

Regards,
John

[HHJ]

I don''t quite understand why the position of Polaris is important since it isn''t mentioned in the sailing instructions. I also don''t quite understand why the instructions ae hard to follow. It sounds to me like he was told to keep the Bear constellation to his left.

I have always found that the easiest way to hold a compass course while sailing at night is to get on course, then find a star that aligns with a convenient point on the mast or shrouds and keep it there. Sounds exactly what Ulysses was being told to do.

[jcmannone]

Polaris isn’t mentioned since it is a marginally bright star 21 degrees from North. If Ulysses just keeps The Bear to his left, he will be sailing way off course to the East. You can fix on a star like you mentioned as long as you won’t be sailing throughout the night. Stars will appear to move and will not provide a constant directional fix.

I went back to Starry Night Backyard to take a closer look at the skies in Athens, Greece 1000BC.

I think I figured it out! At least an attempt:

In the early fall (say mid October), the sky is dark enough to see Pleiades (M45) rising ENE around 7:30 PM. So Ulysses could take an initial bearing on it. As the evening progresses, M45 follows the ecliptic (the apparent path of the Sun, Moon, and planets) swinging further E clockwise. The Bear (Ursa Major) pivots around the (Celestial) North Pole dragging Bootes in the NNW with it. As long as The Bear is kept off the port side, Ulysses will restrict his course to the East. But this is not good enough. Since he was told to keep an eye on M45 as well, I suspect that he can maintain a reasonable NE course by splitting the difference between U. Major and Pleiades. In the meantime Bootes is setting (most of it is late in setting), but doesn’t provide much help yet. After M45 passes high overhead to the SE, it is of little use to navigate by. He probably tries to maintain the last “reliable” heading until Arcturus, the brightest star in Bootes, rises in the NE. Then he can track it for the next 2 to 3 hours until the Sun rises in the East. As the star fades and the Sun breaks over the horizon, he sets his rudder and sails before he goes to sleep. I have verified that there is a mild (1-2 knots) Mediterranean current flowing in the general direction to his destination. He makes corrections to his course by the stars come nightfall.

What do you think?

John

[SailorMitch]

Makes me think that I''m glad God invented the GPS.

[BigRed56]

Ahoy jcmannone? Are you kidding me or what? Dis ere is one pissed off pirate to think anyone cares. If I''ve told ye all once I''ll tells ye again, Your idiots to even think of such nonsence based on Myth and celestrial navigation of any sort is a complete waste to time and brain power. Why in this day and age of hyperspeed technology .... AARRGGHH, I''ll knock ye fool heads together and ye can ponder de stars circling yer blooming empty skulls. Throw your books and tables and charts and your sextants too over the freeking side and get a grip. Ders women and booze and crime and evil and all sorts of better things to do wit you time. The Pirate of Pine Island

[jcmannone]

BigRed

Apparently you missed the point. This post is intended only for those who wish to think. I recommend you go pirate another thread.

John

[BigRed56]

Jc... Explain it to me how this thread pertains to anything even remotely usefull Today? Think... Think.. no my dear watson thats just the point .The Pirate of Pine Island

[kokopelli9]

Thank you Big Red! I much prefer the stars with a bottle of wine than a discussion of Ulysses.

Kokopuff