- Cycles of Time
- Sun Rise, Sun Set
- Mean solar time -Clock Time
- Apparent Solar Time -Sundial Time
- Orbital period 27.321582 d (27 d 7 h 43.1 min)
- Synodic period (Full Moon to Full Moon) 29.530589 d (29 d 12 h 44 min 2.9 s)
- Inclination 5.145° to the ecliptic
- (between 18.29° and 28.58° to Earth's equator)
- Longitude of ascending node regressing by one revolution in 18.6 years
- Tropical Year --measured from Equinox to Equinox
- The period of time required for the earth to make one complete revolution around the sun, measured from one vernal equinox to the next and equal to 365 days, 5 hours, 48 minutes, 45.51 seconds. Also called astronomical year, tropical year.
- Julian Year -365.25 mean solar days
- Gregorian Year -365.2425 mean solar days tries to keep the vernal equinox occurring on the same day
- Both calendric systems add a leap day every 4 years
- Sidereal Year -the time taken by the Earth to orbit the Sun once with respect to the fixed stars. Hence it is also the time taken for the Sun to return to the same ... 1 sidereal year = 1.00003878 years or The sidereal year is 365 days, 6 hr, 9 min, 9.5 sec of mean solar time ...
- Leap Year -In the Gregorian calendar, years evenly divisible by 4 are leap years. In each leap year, the month of February has 29 days instead of 28. Adding an extra day to the calendar every four years compensates for the fact that a period of 365 days is shorter than a solar year by almost 6 hours.
Exceptions -Years that are evenly divisible by 100 are not leap years, unless they are also evenly divisible by 400
- Mayans & Venus
- Consecutive conjunctions of Jupiter & Saturn Occur every 19.85 years
- Solar - Lunar
- The Saros Cycle
- The saros cycle a period of 223 synodic months (approximately 6585.3213 days, or nearly 18 years 11 days)
- One saros after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur
- A series of eclipses that are separated by one saros is called a saros series.
- Used by Chaldeans (ancient Babylonian astronomers), Hipparchus, Pliny and Ptolemy.
- Stonehenge -An Eclipse Computer?
- Stonehenge astronomical Alignments
- Cahokia and Medicine Wheels
- Anti-Kythra Machine
- Video about Mayan Temples/Observatories
- Mayan Observing Venus--Dresden Codex
Ancient Observations of the planets
- The Pleiades
- In Mythology
- Observing Alignments
- The Pecked Cross --The Cross Petroglyph: An Ancient Mesoamerican Astronomical and Calendrical SymbolRight Click to download a pdf file. Authors: Anthony F. Aveni - Horst Härtung
- The story of Sodom & Gomorra
- Cuneiform tablet re-counting the observation of a "fireball"
- Sumerian observation of an asteroid impact at , Austria and is published in a new book, 'A Sumerian Observation of the Köfels' Impact Event.'
- The Köfels Event
- Phaethon Myth
There are many myths about the Milky Way. But, there is one that stands out above all, as an example of our ancestors’ attempts to explain and understand their observations of events and occurrences in the sky.
The story is of Phaethon, the son of the sun god Helios, and Phaethon’s attempt to drive his father’s chariot of the sun on its daily course across the heavens.
Helios trying to frighten Phaethon into abandoning his mad desire describes the dangers to be met on the course of the sun.
"Heed my words my son, for the path is treacherous. Do not be dragged away by the spinning heavenly axis. Look out for ambushes along the way: look out for the horns of Taurus, the Bull; the claws of Cancer, the Crab; the jaws of Leo, the Lion; the raised bow of Sagittarius, the Archer. Stay away from the south pole; go not too high, nor too low. do not veer off the path: on the right, you will become entangled in the coils of Draco, the Dragon; on the left the glittering Altar. My son, be careful especially of the claws of the deadly Scorpion."
But Helios’s astronomical lesson was to no avail. Phaethon’s fate, and the Earth’s, was sealed and as Helios feared, Phaethon could not control the fiery steeds… he dropped the reins at first sight of the Scorpion, and there was a tumult in the sky.
His wild and uncontrolled ride shook the joints of the axle of the Earth. The celestial sphere was unhinged; the heavens were ablaze from pole to pole, the Earth scorched beneath. The cries of terror of all the people of Earth even reached the ears of mighty Zeus, who hurled a thunderbolt. Phaethon fell from heaven into the River Eridanus; the “‘Golden Age” came to an end. The scorched trail left by Phaethon’s ride can be seen even today. It is the Milky Way!