Idaho Skies Transcript for April 9th and 10th

PAUL
Welcome to Idaho Skies for April 9th and 10th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Hey, the moon is approaching new this week.

RACHEL
Which means the next few mornings are a good time to look for Earthshine.

PAUL
Stargazers will find the moon in the low east-southeast before heading to work.

RACHEL
The crescent moon will be bright, but stargazers will see a faint illumination on the moon’s dark portion. 

PAUL
Because of the glare, Earthshine is easier to see through binoculars.

RACHEL
The moon recently left the neighborhood of Saturn and its rings.

PAUL
Saturn’s ring was a wonder to the early astronomers.

RACHEL
They wondered for example whether or not the rings were solid.

PAUL
19th century physicist James Maxwell argued that the rings couldn’t be solid.

RACHEL
That’s because the inner ring orbits Saturn more quickly than the outer ring.

PAUL
And eventually, the rings would wind up so much that they would get torn up.

RACHEL
It wasn’t until April 9th, 1895 that astronomer James Keeler was able prove that Saturn’s rings weren’t solid.

PAUL
He did this by using a spectroscope to measure the rotational speed across Saturn’s rings.

RACHEL
Specifically, he was measuring the Doppler shift of sunlight reflecting off of the rings.

PAUL
And his measurements proved the spin rate across the rings wasn’t constant like they would be if solid.

RACHEL
Today we know the rings of Saturn consist of swarms of icy particles.

PAUL
Most of those particles are the size of smoke, but some can reach a yard across. 

RACHEL
That’s Idaho Skies for the 9th and 10th of April.

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.