Transcript: December 6 - 12

PAUL
Welcome to Idaho Skies for the second week of December. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
If you don’t mind getting up a little early on Sunday morning the 6th, you’ll find there’s a relatively bright star below the moon.

RACHEL
The star’s name is Spica and it’s the brightest star of Virgo the Maiden.

PAUL
Even farther below and to the left of the moon is an even object, Venus the Morning Star.

RACHEL
Venus is slowly approaching the sun, from Earth’s perspective that is.

PAUL
At the same time, it’s also traveling to the far side of the sun.

RACHEL
This means it’s approaching the full phase and becoming a smaller disk.

PAUL
So you’ll need a telescope to observe its shrinking disk.

RACHEL
By May of next year, Venus will reach the opposite side of the sun from our perspective.

PAUL
Or what astronomers called superior conjunction.

RACHEL
Let’s turn our attention back to the moon, which you can observe very well with just a pair of binoculars.

PAUL
Yes. Be sure to check out the moon for Earthshine using your binoculars.

RACHEL
Earthshine is that faint illumination of the dark portion of the crescent moon.

PAUL
The illumination is sunlight, but this is sunlight reaching the moon by way of Earth.

RACHEL
That’s because Earth appears very large and bright in the lunar sky.

PAUL
In fact, it’s about four times more reflective and four times larger than the moon appears to us.

RACHEL
So in other words, the full Earth reflects about 16 times as much light as the full moon.

PAUL
This amount of sunlight reflecting off of Earth illuminates the lunar surface more brightly than the full moon illuminates Earth’s surface.

RACHEL
The light is so bright on the moon that we can often see some of the lunar maria located on the dark portion of the moon.

PAUL
The moon approaches very close to Venus on the morning of the 7th.

RACHEL
You might want to take a minute before leaving to work to enjoy this very nice astronomical sight.

PAUL
That’s because brilliant Venus will only be one degree from the moon.

RACHEL
Meaning both appear together in your binoculars on the morning of the 7th.

PAUL
And Earthshine should still be prominent on the dark portion of the moon.

RACHEL
Zubenelgenubi is a wide double-star with a funny sounding name.

PAUL
Unlike many double stars, Zubenelgenubi is easy to split into a pair of stars using binoculars.

RACHEL
And it’s easy to find because the moon passes close to it every month.

PAUL
On the morning of the 8th, say around 6:30 AM, you’ll find Zubenelgenubi to the lower right of the moon.

RACHEL
Can you split it into a double star with just your eyes?

PAUL
If not, then aim your binoculars at the star.

RACHEL
After looking at Zubenelgenubi, turn your attention towards the moon.

PAUL
It’s close to the horizon and a very thin crescent.

RACHEL
That means that if dawn hasn’t begun, you should be able to see Earthshine.

PAUL
That’s Idaho Skies for the second week of December. Next week a meteor shower reaches its peak and we’ll tell you when and where to watch the shower.

RACHEL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Rachel...

PAUL
...and Paul.

RACHEL
Dark skies and bright stars.