Transcript for July 3rd to 9th

RACHEL
Welcome to Idaho Skies for the first week of July. We're your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Earth reaches aphelion at 12:25 PM on the 4th.

PAUL
Just what is aphelion?

RACHEL
Aphelion is the point in any planet's orbit where it's at its greatest distance from the sun.

PAUL
Oh, that occurs because Earth's orbit is not an exact circle.

RACHEL
That's right, it's elliptical.

PAUL
Well just how much farther is Earth from the sun at aphelion?

RACHEL
At aphelion, it's 2% farther from the sun than on average.

PAUL
Hold on a minute. Our summer days are getting warmer at the same time Earth is traveling farther from the sun?

RACHEL
Yep. Earth's distance from the sun is not a factor in our summer climate.

PAUL
So why are summer days warmer if our distance from the sun has nothing to do with it?

RACHEL
The Northern hemisphere is growing warmer because it's tilted towards the sun.

PAUL
That means sunlight is more intense because the sun shines directly down on the Northern hemisphere.

RACHEL
And you can add the greater hours of daylight.

PAUL
Don't forget to add fewer night-time hours.

RACHEL
The combination of more direct sunlight, longer daylight hours and shorter night time hours adds up to make summers very warm.

PAUL
Regulus is the bright yellowish-orange star you'll find to the moon's left on the 7th.

RACHEL
The moon will be found very low in the west after it gets dark, or around 10 PM.

PAUL
Regulus is the brightest star in Leo the Lion.

RACHEL
The constellation was overhead during spring...

PAUL
...but it's fast approaching the sun now.

RACHEL
So get acquainted with Leo now, it won't be visible much longer.

PAUL
Why you're at it, be sure to spend a few minutes observing earthshine illuminating the upper left side of the moon.

RACHEL
However, don't worry if you can't see earthshine on the 7th.

PAUL
Because you'll be able to observe earthshine for the next three or four days.

RACHEL
Are you looking for Jupiter?

PAUL
Well, it's the yellowish-white star to the moon's left on the night of the 8th.

RACHEL
You'll know you're looking at Jupiter because it won't twinkle like the surrounding stars.

PAUL
Now aim your binoculars at Jupiter to see two of its largest satellites.

RACHEL
It's easier to see these satellites if you prop your binoculars on a stationary surface like a tree, wall, or car.

PAUL
The satellites appear as two stars to the left of Jupiter.

RACHEL
These stars will stand out because they form a straight line with the planet.

PAUL
What are the satellites' names?

RACHEL
From the left and going right, the satellites are Callisto and Europa.

PAUL
With a modest telescope, you can see two additional satellites, Ganymede and Io.

RACHEL
They're closer to the glare of Jupiter, that's why you can't see them through binoculars.

PAUL
Ganymede and Io are also located to Jupiter's left like Europa and Callisto.

RACHEL
Watch out if you're looking at them with a telescope.

PAUL
Because telescopes invert images and will make the moons appear on Jupiter's right.

RACHEL
That's Idaho Skies for the first week of July. Twinkle, twinkle little star. Listen next week and we'll tell you why.

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.