Thursday, June 30, 2016

Transcript for July 24th to 30th

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

RACHEL
...and Rachel.

PAUL
Last week you hear that the Blue moon was a second full moon within a month.

RACHEL
That’s the modern definition, but not the original.

PAUL
The original definition named the extra full moon within a season as the Blue Moon.

RACHEL
Typically, seasons have three full moons since there are three months in a season.

PAUL
According to the Old Farmer’s Almanac, the third full moon appearing in a season of four full moons is properly called the Blue Moon.

RACHEL
It was by accident that the Blue Moon got corrupted into the second full moon within a single month.

PAUL
Speaking of the moon, it will help you find Neptune on the 23rd.

RACHEL
The solar system’s 8th planet is always a challenge to locate and see.

PAUL
However, it will appear as a faint star three degrees to the moon’s right on the 23rd.

RACHEL
You’ll need a dark sky location to see it through your binoculars.

PAUL
To find Neptune, point your binoculars at the moon and then shift them to the right until the moon just leaves the field of view.

RACHEL
The brightest star now appearing nearly in dead center is Lambda Aquarii.

PAUL
This star is ˝ of a degree above Neptune, or the same width of the moon.

RACHEL
There is no other star directly below Lambda Aquarii except for Neptune.

PAUL
Meaning that if you see a very faint star below Lambda, you’re seeing Neptune.

RACHEL
The 7th planet is next to the moon after midnight on the 26th and it’s much easier to see than Neptune.

PAUL
On the 26th, Uranus is 4 degrees above the moon.

RACHEL
So to see Uranus, aim your binoculars at the moon and then shift them up until the moon at the bottom of your binocular’s field of view.

PAUL
You’ll see a narrow quadrilateral of four stars just above the center of the field of view.

RACHEL
Look above the quadrilateral for an even brighter star.

PAUL
The brighter star is Uranus.

RACHEL
There are star maps to help you locate both Neptune and Uranus on the Idaho Skies Twitter account.

PAUL
Early risers will discover that the moon forms a large triangle with two star clusters as they drive to work on the 28th.

RACHEL
The star clusters are named the Pleiades and the Hyades.

PAUL
Both star clusters are pleasing binocular objects.

RACHEL
And you’ll see around two dozen stars in each through your binoculars.

PAUL
Hey, the moon passes through the Hyades star cluster on the morning of the 29th.

RACHEL
Cool, the Hyades and moon will fill the field of view of your binoculars.

PAUL
The brightest star appearing above the moon is called Aldebaran.

RACHEL
Aldebaran is not a true member of the Hyades star cluster; it’s just a foreground star.

PAUL
That’s Idaho Skies for the fourth week of July. The thin crescent moon appears next to Jupiter next week.

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.

Transcript for July 17th to 23rd

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

PAUL
...and Paul.

RACHEL
The nearly full moon is surrounded by star clusters and nebulae on the 17th.

PAUL
Many of them are visible in binoculars as fuzzy spots and small knots of stars.

RACHEL
The star clusters and nebulae are located in the thickest part of the Milky Way.

PAUL
And that means it’s towards the center of our galaxy.

RACHEL
To see these star clusters and nebulae, scan the sky around the moon with binoculars.

PAUL
Remember that it’s easier to see the star clusters and nebulae if you move the moon out of your binocular’s field of view.

RACHEL
Why are these nebulae glowing with their own light?

PAUL
Well, there are two reasons nebulae glow.

RACHEL
The one case, some nebulae are located next to bright stars.

PAUL
The starlight reflects off of the dust filling the nebulae.

RACHEL
In long duration photographs, these nebulae are bluish-white in color.

PAUL
Astronomers call these nebulae reflection nebulae.

RACHEL
And the other kind of nebulae?

PAUL
Young and very hot stars are embedded in these kinds of nebulae.

RACHEL
Since the stars are hot, they emit lots of ultraviolet radiation.

PAUL
The ultraviolet makes the low pressure gas inside the nebulae glow like a fluorescent light or black light poster.

RACHEL
Astronomers call this emission nebula.

PAUL
And in astronomical photographs, these nebula appear red in color.

RACHEL
One of the most famous reflection nebulae is the glowing cloud of dust surrounding the Pleiades.

PAUL
Arguably, the most famous emission nebulae is the Orion Nebula.

RACHEL
Funny thing though, it appears green through an amateur telescope.

PAUL
Green? Why green?

RACHEL
There’s lots of red glowing hydrogen inside the Orion nebula, but our eyes are not very sensitive to red.

PAUL
The green comes from less abundant oxygen atoms that have lost two electrons.

RACHEL
Our eyes are much more sensitive to color green than to red.

PAUL
So even through there’s more hydrogen in the Orion Nebula, the green glow from oxygen overwhelms the red glow of hydrogen.

RACHEL
The moon is full on the 19th.

PAUL
The full moon in July is called the Thunder Moon.

RACHEL
Thunder moon? Why?

PAUL
Probably because in the eastern US, thunderstorms are more prevalent during this time of year.

RACHEL
Doesn’t each full moon have a name?

PAUL
Yes they do. Different cultures give the full moons different names.

RACHEL
So which moth has a full moon called the Blue Moon?

PAUL
None, really.

RACHEL
What?

PAUL
Yep. In one definition, the Blue Moon is the second full moon within any month.

RACHEL
There’s another definition?

PAUL
Yes there is, but we’re out of time.

RACHEL
So we’ll have to discuss this further next week.

PAUL
That’s Idaho Skies for the third week of July. See if you can find the outer planets next week.

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

For Idaho Skies this is Rachel...

PAUL
...and Paul.

RACHEL
Dark skies and bright stars.

Transcript for July 10th to 16th

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

RACHEL
...and Rachel.

PAUL
The brightest star of Virgo is located below the moon on the 11th.

RACHEL
Its name is Spica and it appears as a twinkling white spark of light in the low southwest.

PAUL
The reason stars twinkle and planets don’t is that planets have larger apparent surfaces than stars.

RACHEL
That’s right. Even though stars are much larger than planets, planets are tremendously closer to Earth.

PAUL
The planets’ closeness to Earth trumps the massively large size of stars and gives planets their larger apparent surfaces.

RACHEL
Because of their larger apparent surfaces, it takes more moving pockets of air to make planets twinkle.

PAUL
As a result, the normal movement of air makes star twinkle...

RACHEL
...but not planets.

PAUL
Unless of course, the air is very stormy.

RACHEL
Stars twinkle when moving pockets of air bend and refract their light.

PAUL
Each air pocket has a different temperature, density, and direction of movement.

RACHEL
So each air pocket behave like a prism with its unique optical property.

PAUL
So when a new pocket of air moves over a star, it refracts the position and colors of the star towards or away from your eye.

RACHEL
And that’s star twinkle in a nutshell.

PAUL
The star directly below the moon on the 13th is called Zubenelgenubi.

RACHEL
Zubenelgenubi is a famous double star, but one that many listeners may not have heard of before.

PAUL
The distance between Zubenelgenubi and the moon is 4 degrees...

RACHEL
...or small enough that you can see both the moon and Zubenelgenubi at the same time in a pair of binoculars.

PAUL
The distance between the two stars in Zubenelgenubi is wide enough that your binoculars can resolve the stars as individuals.

RACHEL
The real challenge is to see if you can resolve Zubenelgenubi as two stars with you’re your eyes.

PAUL
Some people can.

RACHEL
On the 15th, the ringed planet Saturn is the yellowish-white star located 2.5 degrees below the moon.

PAUL
While binoculars don’t reveal anything about the planet, a telescope of modest power is enough to let you can see its rings and largest satellite.

RACHEL
This means a spotting scope or small telescope is powerful enough.

PAUL
You’ll need a magnification of at least 25 times, however.

RACHEL
What about Titan, Saturn’s largest satellite?

PAUL
It appears as a star to Saturn’s upper right in a small telescope.

RACHEL
A spotting scope, which doesn’t flip images, will show Titan to Saturn’s lower left instead.

PAUL
In professional telescopes, Titan appears as a tiny orangish disk.

RACHEL
The orange comes from the thick clouds surrounding the satellite.

PAUL
Wait, Titan has an atmosphere of nitrogen and methane and those are colorless gases.

RACHEL
Well, solar ultraviolet acting on the methane gas in Titan’s atmosphere is converting the methane gas into more complex molecules.

PAUL
And those gases creates Titan’s pumpkin-colored clouds.

RACHEL
Astronomers call the orange compounds in Titan’s hazy atmosphere Tholins.

PAUL
And they just might be some of the precursors of life on Earth, 3.8 billion years ago.

RACHEL
That’s Idaho Skies for the second week of July. We’ll talk about great glowing clouds of gas next week.

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.

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.

Saturday, June 11, 2016

Transcript for June 19th to 25th

RACHEL
Welcome to Idaho Skies for the third week of June. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The moon is close to Saturn on the night of the 18th and morning of the 19th.

PAUL
That night, Saturn appears as the yellow-white star to the moon’s lower right.

RACHEL
You’ll need at least a spotting scope or small telescope to see its rings and largest satellite, Titan.

PAUL
Your telescope needs a magnification of at least 25 power.

RACHEL
In a telescope, Titan will appear as a star to Saturn’s lower left on the 18th and 19th.

PAUL
Titan rapidly changes its position with respect to Saturn each night.

RACHEL
The reason for the rapid change is that it only takes Titan 16 days to orbit Saturn.

PAUL
Which is only half as long as it takes the moon to orbit Earth.

RACHEL
Titan is perpetually cloud covered.

PAUL
Sadly, that means there’s no majestic view of Saturn in Titan’s sky.

RACHEL
Only a hazy pumpkin-colored sky.

PAUL
If Saturn were visible on Titan however, the planet would appear 10 times larger than our moon appears to us.

RACHEL
Late on the 19th and after midnight on the 20th you’ll find lots of nebulae and star clusters strewn about the moon’s left side.

PAUL
Star clusters and nebulae are concentrated in this part of the sky because it’s towards our galaxy’s stellar-rich center.

RACHEL
But don’t worry if you can scan this region with binoculars on the 20th.

PAUL
Because you’ll find the same region to the moon’s right on the 21st.

RACHEL
The moon is full on the 20th.

PAUL
The full moon in June is often called the Strawberry Moon.

RACHEL
It’s also the Summer Solstice on the 20th.

PAUL
Hey, that means it’s the first day of summer.

RACHEL
Did you know that solstice means sun standing still?

PAUL
I did.

RACHEL
It gets this name because when you watch the sun’s setting location on the horizon, it appears to stop moving around this time of the year.

PAUL
In fact, around the day of the solstice, the sun sets its farthest position north.

RACHEL
Also on the first day of summer, the length of day is its longest and the night it’s shortest.

PAUL
But that’s not the same thing as the earliest sunrise or latest sunset.

RACHEL
The earliest sunrise occurs about a week earlier than the solstice and the latest sunset occurs a week later.

PAUL
Capricornus the Sea-goat is a large constellation.

RACHEL
But it’s not made up of very bright stars.

PAUL
That means it easier to locate when the moon passes through it.

RACHEL
And that happens on the night of the 23rd.

PAUL
Go to a dark location if you want to find Capricornus.

RACHEL
Capricornus will look more like a big grin than it does a mix of goat and fish.

PAUL
And the moon is located on the upper-right lip of Capricornus.

RACHEL
That’s Idaho Skies for the third week of June. Next week we’ll tell you about a lunar occultation that you can observe from Boise.

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.

Transcript for June 12th to 18th

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

RACHEL
...and Rachel.

PAUL
The moon reaches first quarter on the 12th.

RACHEL
The first quarter moon appears as a half moon and it's the best phase for lunar observations.

PAUL
The reason why is that at first quarter, the boundary between lunar day and night faces directly towards Earth.

RACHEL
This gives the moon's morning shadows their longest apparent length.

PAUL
Long shadows bring out small changes in elevation.

RACHEL
In fact, elevation changes smaller than one hundred feet are visible on the moon when it's nearly 240,000 miles away.

PAUL
Spica, the brightest star in otherwise dim Virgo, is the bright pinpoint of light below the moon on the 14th.

RACHEL
Hey, can you make out the constellation of Corvus the Crow, which is further below Spica?

PAUL
It's the lop-sided square of four stars below and slightly right of Spica.

RACHEL
Corvus the Crow appears in the sky because the Greek god Apollo threw it into the sky during a fit of anger.

PAUL
Let that be a warning not to tell lies to Greek gods.

RACHEL
Mars is the orange beacon signaling you from a position below the moon on the night of the 16th.

PAUL
Mars was recently at opposition, so it's still relatively close to Earth.

RACHEL
But Mars is only half the diameter of Earth.

PAUL
Meaning it can be difficult to make out surface detail on this world even through a telescope.

RACHEL
While you can't see any Martian features through binoculars, you can split the double star that's located to the lower right of the moon.

PAUL
The star's name is Zubenelgenubi and its half the apparent distance from the moon as Mars.

RACHEL
The star appears as a significantly fainter white point of light when compared to Mars.

PAUL
Some people can split Zubenelgenubi into two stars with just their bare eyes, can you?

RACHEL
If not, then like the rest of us, you'll need to use binoculars.

PAUL
Late on the 17th and early on the 18th, the moon is just above the head of Scorpius the Scorpion.

RACHEL
The brightest star of Scorpius is Antares.

PAUL
Which is a super red giant star.

RACHEL
That's right. Red giant stars are stars nearing the end of their lives.

PAUL
That means someday soon, Antares will explode in a supernova explosion.

RACHEL
The explosion occurs when the core of the star stops fusing fuel into heavier elements and energy.

PAUL
Without its internal energy source, gravity makes the star's core collapse.

RACHEL
After the massive core squeezes itself into a neutron star, it rebounds slightly.

PAUL
The star's outermost layer is raining down as the core rebounds.

RACHEL
The impact between the falling outer layer and rebounding core creates a shockwave that rushes through the rest of the star.

PAUL
The result is a massive amount of fusion and titanic explosion that blows away the outer layer of the star.

RACHEL
In the fiery debris, fusion reactions create heavier elements like gold and platinum.

PAUL
That means the world's wealth of gold and platinum exists because of stars that died many billions of years ago.

RACHEL
That's Idaho Skies for the second week of June. Next week is the first day of summer.

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.

Tuesday, May 31, 2016

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.