Transcipt: 8 - 14 November

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

RACHEL
...and Rachel.

PAUL
Listeners have an opportunity to see Earthshine and three planets on the 8th.

RACHEL
You’ll need to go out by 5:00 AM, however.

PAUL
Look in the low east and you’ll see the following, going up from the horizon.

RACHEL
The moon...

PAUL
Venus...

RACHEL
Mars...

PAUL
And finally Jupiter.

RACHEL
The four largest satellites of Jupiter appear near the extremes of their orbits.

PAUL
So your binoculars could potentially show all four of the Galilean satellites.

RACHEL
In binoculars, the satellites will form a line going from the bottom left to the upper right.

PAUL
From the bottom left and going up to the right, the moons are Ganymede, Io...

RACHEL
...then Jupiter...

PAUL
...followed by Europa and finally Callisto.

RACHEL
Europa will be the closest to Jupiter and the most difficult to see.

PAUL
However, a small telescope will show you Europa even if binoculars can’t.

RACHEL
Be aware however that the order of the satellites will be flipped if you look at them through your telescope.

PAUL
If you missed seeing Earthshine on the 8th, you have another chance beginning on the 13th or 14th.

RACHEL
Do you remember that last week the moon pointed out two bright stars with white dwarf companions?

PAUL
Sure, but what exactly are white dwarf stars?

RACHEL
They’re old stars with mass, or weight, too low to generate enough heat and pressure to fuse carbon and oxygen into heavier elements.

PAUL
Recall that stars use their mass to squeeze the hydrogen in their cores into helium.

RACHEL
After fusing a lot of its hydrogen into helium, most stars generate enough heat and pressure to convert that helium into carbon and oxygen.

PAUL
However, white dwarf stars can’t create enough heat and pressure to fuse that carbon and oxygen in their cores into even heavier elements.

RACHEL
Since they can no longer fuse elements, they no longer have an internal energy source.

PAUL
So they collapse until the repulsion between electrons is the only thing supporting their weight.

RACHEL
That collapse turns a star the size of the sun...

PAUL
Which is about 800,000 miles across...

RACHEL
...into a star the size of Earth...

PAUL
Which is 8,000 miles across.

RACHEL
That means white dwarfs are very dense.

PAUL
In fact, a piece of white dwarf the size of a sugar cube would weigh as much as a car.

RACHEL
Over billions of years, white dwarf stars cool until we can no longer see them.

PAUL
And this is the fate of 97% of the stars in our galaxy.

RACHEL
Including our sun.

PAUL
But have no fear, that won’t happen for another five billion years.

RACHEL
That’s Idaho Skies for the second week of November. Next week Earth passes though the debris tail of a comet and we’ll tell you what that means for Idahoans.

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

For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.