I. Polaris

Aim: What is the relationship between latitude and Polaris? Do now: Using your ESRT, page 5, tell me the latitude and longitude of the following locations. Be sure to locate the equator and Prime Meridian before determining the directions North, South, East or West. 1) Yellowstone Hot spot 2) Bouvet Hot spot 3) Tasman Hot spot

1) Yellowstone Hot spot (in North America)

2) Bouvet Hot spot (South of Africa)

3) Tasman Hot spot (Off east coast of Australia)

I. Polaris: The North Star •

•

•

Brightest star in the sky.

Always in the northern sky. It is the tail of the little dipper

•

Polaris' altitude in the sky above the horizon is equal to an observer's latitude.

As your latitude North increases, the altitude of Polaris increases.

WATCH THE ANIMATION

•

•

Polaris’ altitude does not change when you move East or West

Polaris

Polaris

420 N Latitude Equator

Equator

Polaris

900 N Latitude

Equator

II. How do you find the North Star?

• The “pointer stars” from the big dipper point to the star Polaris.

III. Polaris and Earth

• Polaris is located 400 light years away from Earth. • It is positioned in-line with Earth’s North Pole.

Since Polaris is in-line with the North Pole, the other stars appear to Rotate around Polaris as Earth Rotates.

The stars appear to rise in the Eastern sky and set in the Western sky

Closure ► 1.

What is the latitude of an observer if the altitude of Polaris is 43°?    

A) 23 N B) 90 N C) 43 N D) 43 S

Answer:

C

► 2.

A person knows he solar time on the Prime Meridian and the local solar time. What determination can be made?    

A) the date B) the altitude of Polaris C) the longitude at which the person is located D) the latitude at which the person is located

Answer: C