Idaho Skies Transcript for the week of December 2nd

PAUL

Welcome to Idaho Skies for the week of December 2^nd. We’re your hosts, Paul

STEPHEN

…and Stephen.

PAUL

It’s easy to be a rock star when there are no bright stars near you. And that’s definitely true for Fomalhaut, the star below the moon on the 3^rd. Astronomers rate Fomalhaut as first magnitude. It was the ancient Greeks who designed this magnitude system as a way to classify stars by their apparent brightness.

STEPHEN

They designed the magnitude system to start with a one for the brightest stars and six for the faintest the unaided eye can see. There are 17 stars brighter than Fomalhaut and some of them have negative magnitudes. For example, Sirius, the bright star rising at 9:45 PM this evening is magnitude is -1.5.   

PAUL

The moon reaches first quarter minutes before midnight of the 4^th. That means it looks so close to first quarter on the 3^rd that you won’t see the difference. First quarter occurs when the angle between the sun, Earth, and moon is 90 degrees. So the moon is nearly due south as the sun sets in the southwest.

STEPHEN

Recall that the sun always illuminates exactly half of the moon. Therefore, at first quarter we can only see half of the illuminated lunar surface. Lunar seas or lava plains cover much of the northern half that we can see and craters fill the southern half. This makes the first quarter phase the perfect moon for exploring with binoculars.   

PAUL

That’s Idaho Skies for the week of December 2^nd.  

STEPHEN

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

For Idaho Skies this is Stephen

PAUL

…and Paul.

STEPHEN

Dark skies and bright stars.