Download Celestial Navigation

Celestial Navigation
Ancient Greece
{ Kennedy & Brett
Constellations
•
We inherited most of the names for our constellations from the Greeks. They
named them after mythological heroes and legends that they believed in.
•
Behind every constellation is a story. In Greek mythology, Orion was a great
and handsome hunter. The constellation commonly known as “Orion the
Hunter”. It is one of the largest and brightest constellations in the sky, and is
easy to spot from the Northern hemisphere.
Another famous constellation according to ancient Greek is called Arktos the
bear, or what we call the big dipper. This is one of the easiest constellations
to spot in the night sky.
•
Sea Travel


In Europe, the Greeks
were the first of
Mediterranean sailors to
navigate far from land
and to sail at night.
They used observations of
the sun and north star
(Polaris) to determine
directions, they estimated
from the time it took to
cover them
How They Used Them
• In the 3rd century BCE the Greeks had begun to
use “Little Bear”, or Ursa minor to navigate. In
Europe, The Phoenicians and Greeks were the
first of the Mediterranean sailors to navigate
far from land and to sail at night using celestial
navigation. They used observations from the
Sun and the North Star (Polaris) to determine
directions.
• They estimated distances from how long it
took to travel or cover them. To navigate along
a degree of latitude a sailor would need to find
a circumpolar star above that degree in the sky.
You can figure out your latitude by how high
Polaris appears in the night sky.
The Astrolabe
•
•
Ancient Greek astrologists, astronomers, and navigators were the first ones
to invent the astrolabe.
An astrolabe is a navigation instrument. It is a brass inscribed disk with the
edge marked in degrees(or days/months) and a pointer that you direct at the
celestial object you are measuring. They were both portable and useful.
With an astrolabe you can measure:
position of celestial objects
measure the time of the night (or of the day, using it as a mobile sundial or,
more accurately by measuring the altitude of the sun)
measure the time of the year
determine the altitude of any object over the horizon
determine the current latitude
The Astrolabe
•
•
•
•
The name comes from the Greek words “astron” and “lambanien” meaning
"the one who catches the heavenly bodies”
The 1st one was developed in Alexandria in 160 BC. The first astrolabe is
credited to the Greek astronomer and mathematician Hipparchus.
After this the Mariner’s astrolabe was invented for ships at sea. This was
much larger. The Mariner's Astrolabe was used to determine the latitude of a
ship at sea by measuring the noon altitude of the Sun or a star.
Over the past centuries the astrolabe has been developed and made much
more complex, but is still an instrument that is used today by navigators.
Sources
wikipedia.com
Ancient Greece! By
Avery Hart
celestialnavigation.net
erikdeman.de
space.com
visav.phys.uvic.ca
Smart-opedia by Eve
Drobot