Idaho Skies Transcript for March 18th and 19th

PAUL
Welcome to Idaho Skies for March 18th and 19th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
A bright yellowish star appears next to the moon on the 18th.

RACHEL
The star’s name is Regulus and its only three degrees away from the moon. Three degrees of separation means that you can see both together through binoculars. Regulus is the brightest star of Leo the Lion. Leo the Lion is one of the signs of the zodiac. Did you know that there aren’t 12 constellations in the zodiac? 

PAUL
First off, we should explain that the zodiac is a series of constellations that the sun, moon, and planets travel though. Now there are twelve signs of the traditional zodiac, but the sun travels through 13 constellations over the course of a year. So why this mismatch? Well, in a word it’s because of precession.   

RACHEL
Precession results from a wobble in Earth’s spin axis. Earth spins on its axis once every 24 hours to create day and night. However, the spin axis itself spins in a larger circle over 26,000 years. So when the zodiac was designed 2,000 years ago, the sun did indeed pass through 12 constellations according to the ancients. 

PAUL
Earth’s spin axis has wobbled through 7% of its path in the last 2,000 years. Because of this and the new boundaries for the constellations that astronomers created last century, the zodiac includes a new constellation, Ophiuchus. Ophiuchus is the Serpent Bearer and it’s above Scorpius the Scorpion. I wonder how many of our listeners are Ophiuchians? 

RACHEL
That’s Idaho Skies for the 18th and 19th of March.

PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.