1. Star Maps – Constellations SNC1D
Expectations: D2.2, D3.6

2. Constellations

3. What is a star? A STAR is a large sphere of glowing gases.
Stars change over time.
Which is the closest star to Earth?
THE SUN!
The sun is a medium sized star
MUCH, MUCH larger than Earth

4. Stars as Tools for Navigation
The North Star is called Polaris and located directly above the North Pole. This star appears in the same place every night all year long.
In the Northern Hemisphere, if you find Polaris you will be able to tell which direction is north.
The Southern Hemisphere does not have a star to help you find its pole. Instead it has what is known as a Southern Cross.
The Southern Cross consists of 4 bright stars and some dimmer ones. All of these together point to the south pole.

5. Time Lapse – Night Sky - Polaris

6. The Southern Cross

7. Seeing the Constellations
The bulge of the earth hides stars from view. From the far north the Big Dipper is high in the Sky but the Southern Cross is invisible.

8. Seeing the Constellations
From the far Southern Hemisphere, the Southern Cross is high in the sky but the Big Dipper is hidden.

9. Seeing the Constellations
From the equator, all stars in the sky are visible at some time or other. From near the equator you can see both the Big Dipper and the Southern Cross. In fact, since they are on the same side of the sky, you can see them both at the same time. Well, not exactly, unless you have fish-eye vision, but they are in the sky at the same time.

10. Directions in the Sky North is toward the North Celestial Pole
South is toward the South Celestial Pole
East is toward East on the ground (usually)
West is toward West on the ground (usually)

11. Patterns of Stars
People of ancient time saw the constellations as character or animals in the sky. They made up stories to explain how the object, animal, or character came into the night sky.
A pattern or group of stars in the sky is called a constellation.

12. Star Patterns

13. The Big Dipper

14. The Big Dipper

15. CONSTELLATIONS Constellations are imaginary patterns of bright stars.
The ancient Greeks invented the constellations we call the twelve signs of the zodiac.

16. Constellations A grouping of stars.
Ursa Major (big bear- can you see the Big Dipper?)

17. Constellations
Earth rotates on its axis, this makes most constellations appear to rise in the east and set in the west during the night.
Most constellations appear in many different positions in the sky as the Earth revolves around the sun.
There is a group of stars that appear in the sky all night long and all year long. It seems that these stars do not rise and set, but circle the Earth’s north pole each night. These stars are called circumpolar.

18. CONSTELLATIONS CONT. There are eighty eight official constellations.
Some examples are: Big dipper, Orion, Gemini, Little dipper.

19. STAR CHARTS How can we identify constellations in the night sky?
The use of a star chart can help us!
A STAR CHART is a map of the stars in the night sky.

20. STAR CHARTS
On a star chart, lines often connect the stars that might make up a constellation.
Different star charts must be used at different times of the year and in different places on Earth.
Many stars visible from the Southern hemisphere cannot be seen from the Northern hemisphere.

21. STAR CHARTS

22. Star Map
Map of the night sky that shows the positions of the stars in a particular part of the sky.
Can be used for navigation. (still used by sailors)
All stars in the Northern Hemisphere appear to revolve around Polaris (the North Star).
The stars close to Polaris are visible all year.
Example: planisphere displays date and time to locate stars, constellations and galaxies.

23. What is a planisphere? A planisphere is a map of the night sky.
It helps sky gazers to figure out where the constellations should be.

24. Before we begin…
We need to know some common basic terms, and we need to know directions.

25. Horizon
The horizon is the place where earth meets sky.
Horizon

26. Zenith
the point of the celestial sphere that is directly over the observer and 90 degrees from all points on that person's horizon
The top of the sky!

27. Azimuth
the angular distance along the horizon between a point of reference, usually the observer's bearing, and another object

28. How to use a compass… A compass always points North.
Make the compasses on the table line up with the N.
Point to East
Point to West

29. Ecliptic
The path across the sky celestial objects appear to follow over the year.

30. Let’s look at the planisphere
Time
Date
The very center of the circle is the zenith, the highest place in the sky; right above your head!
Everything inside the black oval is the sky
Horizon
Star Wheel copied from

31. Calendars
Many First Nations groups noted that that the appearance of certain patterns marked the changing of the seasons.
Ancient Egyptian farmers noticed that the annual flooding of the Nile River, used for crop irrigation would occur every 365 days when the Sun passed through the constellation Leo.
Others lined up stones with the Sun’s path in the sky and were able to track the start and end of each season.

32. Soltices and Equinoxes
Ancient Mayans built a giant pyramid that is aligned to the Sun’s movement in the sky. At sunset on the spring and fall equinoxes, a corner of the structure casts a shadow that resembles a plumed snake slithering down the pyramid steps.

33. Newgrange, Ireland

34. On the day of the Winter Solstice, the burial chamber of Newgrange is illuminated for 17 minutes.
The ancient Irish used Newgrange for both a calendar and a sacred building for the community.
Newgrange dates from 3000 BC – much older than the pyramids of Egypt and Stonehenge in England
Diagram of the passage inside Newgrange of the passage inside Newgrange

36. Stonehenge Circular arrangement of giant stones and boulders.
At sunrise on the summer solstice every year, the Sun’s first rays strike a particular stone.

37. Other Views
Some West Coast Natives tell of the stars being formed when the sleeping Sun’s mouth spewed sparks through the smoke hole of it house. As the Sun slept, its brother, the Moon, rose in the east.
In other First Nations legends, lunar eclipses are the result of monsters in the sky swallowing the Moon.

38. Azimuth
The horizontal angular distance from north measured eastward along the horizon. (North 0º, East 90º, etc.)

39. Altitude
The angular height an object appears above the horizon, measured vertically.

40. Hand Angles
Finger 1º
Fist 10º
Outstretched hand 20º

41. Homework Planisphere construction
Using the planisphere, answer the worksheet questions.