Download Patterns in the Sky

8.6: Patterns in the Night Sky
Key Concepts:
1. Careful observation of the night sky can offer clues about the motion
of celestial objects.
2. Celestial objects in the Solar System have unique properties.
3. Some celestial objects can be seen with the unaided eye and can be
identified by their motion.
4. The Sun emits light and other forms of radiant energy that are
necessary for life to exist on Earth.
5. Satellites have useful applications for technologies on Earth.
6. The study of the night sky has influenced the culture and lifestyles of
many civilizations.
- It is believed that celestial objects are connected to events on Earth.
- The stars are used for navigational purposes and references points.
Constellations
Constellation: a group of stars, as observed from Earth.
- The stars in the night skies form specific patterns in the night sky.
- These patterns have been named by many cultures, using names of heroes,
mythical monsters, and animals.
- Uras Major is the constellation that the Big Dipper is found.
- There are 88 constellations recognized.
- Different cultures named the same constellations differently as they used
their imagination to group the stars.
- Orion (a great hunter), named by the Greeks, was also named as a canoe by
the First Nations peoples of North America.
- Official constellations have names from the Greeks and Arabic mythology.
- Although we look at the constellation that our ancestors view, some of the
component stars have moved.
- Stars closer to our sun move faster then those located further away.
Figure 2: The constellation Orion can appear in the pattern of a hunter.
Figure 3: The stars of the Big Dipper are moving, but so slowly that the
change is only noticeable over many years.
Mapping the Stars
- A star map shows the locations of stars in the night sky, unaided and aided.
- The map can be used to view recognizable objects, like constellations.
- Star maps can also be used to determine location on Earth.
- A planisphere can be used to locate stars, constellations and galaxies,
during specific dates and times of the year.
Figure 4: Star maps show the stars in a certain region of the sky.
The Celestial Sphere
- From Earth we can only view the sky as it appears, but this is not as it is in
space.
- A celestial sphere is an imaginary sphere of which celestial objects are
placed.
- This sphere encircles Earth.
- The celestial sphere is divided into a northern and southern hemisphere,
and can used as a navigational tool.
- The North and South Celestial Poles extend out into space from the north
and south poles.
- The north celestial poles points to Polaris, the North star.
Figure 5: The Celestial Sphere