AIM: WHAT IS THE CELESTIAL SPHERE?

DO NOW:1. WHICH DATE BEGINS THE SUMMER SOLSTICE?2. WHERE DO THE SUNS DIRECT RAYS STRIKE DURING THE

EQUINOX? 3. HOW MUCH DARKNESS DOES THE NORTH POLE GET DURING

THE WINTER?4. HOW MANY HOURS OF DAY AND NIGHT DO WE GET DURING

AN EQUINOX SEASON?5. HOW MUCH DAYLIGHT DOES THE SOUTH POLE GET DURING

THE SUMMER?

WHAT DOES THE CELESTIAL SPHERE LOOK LIKE? It’s an imaginary dome which shows the earth/observer in the center.

It helps us identify the seasons, by the altitude of the noon sun.

It shows us where the Zenith is.

The Zenith is the point directly overhead.

It shows the location of sunrise and sunset.

What do we need to know about the Celestial Sphere?

• 1. We need to recognize the change in altitude of the noon sun.• 2. We need to identify each season.• 3. We need to identify the location of

sunrise and sunset.• 4. We need to recognize when an

observer is in the northern hemisphere, the altitudes will all be in the southern sky.

Lets practice Regents questions!• Check out some regents questions about the celestial sphere• More Questions!

• This is an observer located in the mid-latitudes (around 40-450). The protractor represents the altitude of the noon sun.

• • Put a star at 900. That is the ____________________________________________________• Label compass directions South, East, and West.• What is the angle of Earth’s tilt? ________________________________________________• Find that on the south side of the protractor; put a star on it. This represents the season when the sun does

not stay out for a long time. Which season is it?______________________• Earth’s tilt times 2 equals: ______________________. Put a star on that number.• This represents the season of equal days and equal nights. AKA _________________________• Earth’s tilt times 3 equal: ___________________. Put a star on that number.• This represents the season when the sun stays out for a long time. Which season is it? ______• Earth’s rotation causes the sun to appear to rise in the _________ and set in the ___________• During winter the sun rises a little south of east and sets a little south of west. Let’s draw!• During the spring and fall the sun rises exactly due east and sets exactly due west. Let’s draw!• During the summer the sun rises north of east and sets north of west. Let’s draw!• • ** Important: The sun is only directly overhead at the __________________! No place else on Earth!