Transcript for May 29th to June 4th

RACHEL
Welcome to Idaho Skies for the fifth week of May. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
The moon is last quarter on the 29th.

PAUL
Which means it’s also a nice to observe the moon through your binoculars.

RACHEL
More importantly, the moon has a neighbor that night and it’s a bit of an astronomical challenge to see.

PAUL
The challenge is our eighth planet, Neptune.

RACHEL
This icy giant planet is just 4.5 degrees away from the moon on the 29th.

PAUL
That means you can see both together in a pair of binoculars because binoculars typically have a field of view of 5 degrees.

RACHEL
You’ll need dark skies in order to see Neptune, so leave town for the countryside.

PAUL
Once in a dark location, place the moon on the right edge of your binoculars.

RACHEL
Then find the brightest star directly east of the moon and the far edge of your binoculars.

PAUL
A small distance farther east of the bright star is a faint star that will be as bright as Neptune.

RACHEL
And the distance between the star and the brighter star is the same distance Neptune is away from the bright star.

PAUL
Now Neptune is the other faint star down and slightly left of the bright star.

RACHEL
The bright star, its neighboring faint star, and Neptune will form a small triangle with a 90 degree apex centered on the bright star.

PAUL
It will be better to place the moon outside your view when you search for Neptune.

RACHEL
You’ll find a star map for you to use on both Idaho Skies on Twitter and Blog Spot.

PAUL
If you get a chance to see Neptune, remember that you’re looking at the most distant planet in the solar system.

RACHEL
The average distance between Earth and Neptune is 2.7 billion miles.

PAUL
At a diameter of 30,600 miles, Neptune is almost four times the size of Earth.

RACHEL
Its mass is 17 times greater than Earth.

PAUL
Why only 17 times more massive? Shouldn’t be more like four times four times four or 64 times more massive?

RACHEL
The reason for the discrepancy is that while Earth is rocky, Neptune is mostly water and gas. 

PAUL
The moon is close to the eastern horizon as you drive to work on the 31st.

RACHEL
Can you see Earthshine on the moon?

PAUL
Binoculars will definitely help.

RACHEL
But please don’t use your binoculars while you drive.

PAUL
It’s Saturn’s turn to reach opposition on June 3rd.

RACHEL
This means Earth is passing Saturn as the planets orbit around the sun.

PAUL
The reason Earth can pass the superior planets is because Earth’s orbit around the sun is smaller.

RACHEL
Smaller orbits are closer to the sun and therefore under the influence of a stronger gravitational field.

PAUL
Stronger gravitational fields mean orbital speeds must be higher to maintain a constant distance from the sun.

RACHEL
So if Earth wasn’t traveling faster, then it would spiral into the sun.

PAUL
Barbeque anyone?

RACHEL
That’s Idaho Skies for the last week of May. Next week is another opportunity to see Earthshine.

PAUL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.

For Idaho Skies this is Paul…

RACHEL
…and Rachel.

PAUL
Dark skies and bright stars.