Saturday, January 2, 2016

Constant North Star

The North Star has been a traveler's navigational guide in the Northern Hemisphere for all of recorded history.

Polaris (Alpha Ursae Minoris), another name for the North Star, appears fixed in the night sky. Polaris is positioned as an extension of Earth's axis projected from the Geographic North Pole. To an observer standing near the North Pole, Polaris would be directly overhead.
It is a celestial accident that Polaris is located over the Earth's Geographic North Pole.
Barry López
Because of Earth's rotation and the position of Polaris, all other stars appear to rotate around Polaris. Long exposure photographs reveal what appear to be star trails about Polaris.

As Earth rotates, stars trails appear to streak the across the sky, anchored about Polaris, in a long exposure photograph.
image: Robert Knapp

There is no comparable star located on a line along Earth's axis projected skyward from the South Pole.

As a constant in celestial navigation, Polaris has had many names throughout the course of recorded history. The name Polaris gained acceptance during the 17th century Renaissance. Polaris is a Latin word meaning of or near the pole.

Polaris appears in stellar catalogs as far back as the time of Ptolemy ~ AD 169.

Case Of You
Joni Mitchell

Just before our love got lost you said
"I am as constant as a northern star"
And I said "Constantly in the darkness
Where's that at?
If you want me I'll be in the bar"