Tuesday, September 26, 2017

Idaho Skies Transcript for September 29th and 30th and October 1st

RACHEL
Welcome to Idaho Skies for September 29th and 30th, and October 1st. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Stargazers looking towards the north will find the Big Dipper very close to the horizon.

PAUL
Back in the early spring, it was high above the Northern horizon.

RACHEL
Over the course of one year, the Big Dipper makes one complete revolution around the North Star.

PAUL
It does the same thing in the course of 24 hours.

RACHEL
Actually, it does this in 23 hours and 56 minutes.

PAUL
That 4 minute difference from a 24 hour day is important.

RACHEL
It means all stars, and not just those in the Big Dipper, rise four minutes earlier every night.

PAUL
Which also means the stars appear to rotate a little counter-clockwise each night.

RACHEL
Over the course of the year, each night’s four minute shift adds up to 24 hours.

PAUL
And therefore, the stars begin the new year right where they were last year.

RACHEL
Why the 4 minute shift each day?

PAUL
Because Earth is orbiting the sun.

RACHEL
After each day, Earth shifts 1 degree further in its orbit around the sun.

PAUL
This makes the boundary between day and night shift one degree relative to the sun.

RACHEL
And the angle between Earth and the sun is responsible for when sunset occurs.

PAUL
And one degree equates to 4 minutes.

RACHEL
So this October, watch the Big Dipper skim the Northern horizon.

PAUL
That’s Idaho Skies for the 29th and 30th of September and the 1st of October.

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.

Idaho Skies Transcript for September 27th and 28th

PAUL
Welcome to Idaho Skies for September 27th and 28th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Stargazers will find two astronomical treats on the night of the 27th.

RACHEL
Best of all, they’re right next to each other.

PAUL
First is the moon, it will be at first quarter.

RACHEL
The first quarter moon is half full, which can seem contradictory to its name.

PAUL
So think of first quarter meaning the moon has traveled one quarter of the way around the sky...

RACHEL
...rather than being one quarter full.

PAUL
This is among the best moon phases for your binoculars.

RACHEL
Lunar craters and mountains along the terminator of the moon will display easy-to-see shadows.

PAUL
Which make very small lunar features really stand out.

RACHEL
After observing the moon, then turn your attention beyond the moon’s right edge.

PAUL
You’ll see a creamy yellowish star there. But it’s not really a star.

RACHEL
It’s Saturn, the second largest planet in the solar system.

PAUL
Anyone with a small telescope, or even spotting scope, can see Saturn’s rings.

RACHEL
It only requires a magnification of 25 power to see them.

PAUL
That unfortunately, is beyond the capability of most binoculars.

RACHEL
The moon is residing within the constellation of Sagittarius this fall.

PAUL
To most people, it appears like a teapot of 7 stars.

RACHEL
To help you make out Sagittarius, look for a tilting teapot of stars just below the moon.

PAUL
In dark skies, you’ll find that the Milky Way is the steam rising out of the teapot’s spout

RACHEL
That’s Idaho Skies for the 27th and 28th of September.

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.

Idaho Skies Transcript for September 25th and 26th

RACHEL
Welcome to Idaho Skies for September 25th and 26th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
There’s a sideways W in the sky.

PAUL
Umm, I see a sideways M.

RACHEL
Well, it does depend on your perspective. But in any case, do you know what I’m talking about?

PAUL
Sure, it’s the constellation of Cassiopeia.

RACHEL
Cassiopeia, according to mythology, was the Queen of Ethiopia and wife to King Cepheus.

PAUL
And their daughter was named Andromeda.

RACHEL
But Cassiopeia got in trouble with the Greek god Poseidon.

PAUL
How? By bragging that she was more beautiful than the Nereids, his daughters.

RACHEL
This of course displeased the Nereids to no end, so they asked their father to do something about it.

PAUL
Poseidon decided to send a sea monster to attack the coast of Ethiopia.

RACHEL
Hardly seems fair, does it.

PAUL
The Greek and Roman gods were very human-like for sure.

RACHEL
To appease Poseidon, the king and queen tied their daughter Andromeda to rocks along the coast as a sacrifice to the sea monster.

PAUL
It was just in the nick of time that the Greek hero Perseus stopped the sea monster and rescued Andromeda.

RACHEL
Hey! All these Greek legends appear in the skies tonight.

PAUL
Yep. But first look for Cassiopeia tonight. She’s in the northeast.

RACHEL
To find her, look half way up above the horizon for a pattern of 5 stars arranged in a W tipped on its left end.

PAUL
By the way, the W represents a side view of the queen sitting on her throne.

RACHEL
That’s Idaho Skies for the 25th and 26th of September.

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, September 19, 2017

Idaho skies Transcript for September 22nd, 23rd, and 24th.

RACHEL
Welcome to Idaho Skies for September 22nd, 23rd, and 24th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The Autumnal Equinox occurs on the 22nd.

PAUL
Specifically, it begins at 2:02 PM.

RACHEL
The Autumnal Equinox marks the exact time that the sun stands overhead the equator.

PAUL
On the day it crosses the equator going south, marks the first day of autumn in the Northern hemisphere.

RACHEL
If there were no atmosphere to bend or refract light, then the day would last exactly 12 hours long.

PAUL
Because of our atmosphere, sunrise occurs a few minutes earlier and sunset occurs a few minutes later

RACHEL
Since the first day of summer back in June, the days have been getting shorter.

PAUL
And this will continue until late December.

RACHEL
So enjoy the first day of fall with its longer nights, fresh apples, and pumpkins that it brings.

PAUL
Get your binoculars out and observe the western horizon shortly after sunset on the 22nd.

RACHEL
Because at around 8:15, stargazers will be able to see the three day old moon and Jupiter.

PAUL
Jupiter is approaching the sun, so you don’t have many more days to see the planet.

RACHEL
The moon will appear as a very thin crescent to the upper left of Jupiter.

PAUL
The crescent will be thin enough that very few craters will be visible through binoculars.

RACHEL
And the moon is too close to the well-lit horizon for Earthshine to be visible on the dark portion of the moon.

PAUL
However, over the next two or three days, stargazers will be able to observe Earthshine on the moon.

RACHEL
That’s Idaho Skies for the 22nd, 23rd, and 24th of September.

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.

Idaho Skies Transcript for September 20th and 21st.

PAUL
Welcome to Idaho Skies for September 20th and 21st. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Venus and Regulus continue their celestial dance for the next few days.

RACHEL
Venus is the Morning Star, and very bright in the low east at 6:30 AM.

PAUL
Regulus is the heart of Leo the Lion and the constellation’s brightest star.

RACHEL
To see them, look in the low east at around 6:30 AM before the light of dawn gets too bright.

PAUL
Stargazers will see the pair change their positions relative to each other very dramatically every morning.

RACHEL
Venus is on its way to the other side of the solar system.

PAUL
That means its growing fainter and smaller.

RACHEL
And its phase is becoming closer to full every day.

PAUL
However, Venus is small enough that its phase is not usually observable except through a telescope.

RACHEL
If you have one, then aim it at Venus once the sky has brightened.

PAUL
This way the glare of Venus won’t overwhelm your eyes.

RACHEL
And the planet will appear as a tiny white globe.

PAUL
The moon reappears in the evening sky on the 21st.

RACHEL
It will have the shape of an incredibly thin crescent in the low west.

PAUL
If you have trouble finding it at 8:30, then look for Jupiter.

RACHEL
Jupiter is the bright star in the low west.

PAUL
And the moon will be just a little right of Jupiter.

RACHEL
Get your binoculars out, for this will be a cool sight.

PAUL
Because the moon will be 46 hours past new.

RACHEL
Since people don’t see the moon until its three days old, you’ll have bragging rights after seeing the moon this young.

PAUL
That’s Idaho Skies for the 20th and 21st of September.

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.

Idaho Skies Transcript for September 18th and 19th

RACHEL
Welcome to Idaho Skies for September 18th and 19th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
A very thin crescent moon appears between three planets and a star on the morning of the 18th.

PAUL
This should be a really neat sight on account of the thinness of the moon.

RACHEL
Early-rising stargazers need to look in the low east at around 6:30 in the morning.

PAUL
Above the moon will be brilliant Venus.

RACHEL
And almost equally distant below the moon will be bright Mercury.

PAUL
Between the moon and Mercury will be much fainter Mars.

RACHEL
And between the moon and Venus will be the star Regulus.

PAUL
For the next few mornings, keep an eye on Venus and Regulus.

RACHEL
Since Regulus is a true star, its rises earlier each day and therefore appears higher above the horizon.

PAUL
Venus on the other hand, is traveling to the far side of the solar system, so it appears closer to the sun each morning.

RACHEL
Meaning it rises later and appears lower in the sky.

PAUL
Venus and Regulus will nearly cross paths on the 20th.

RACHEL
So stargazers can watch the two approach very close to each other for the next few days.

PAUL
Then swap their relative places in the sky and grow farther apart.

RACHEL
The change is dramatic and noticeable from one morning to the next.

PAUL
So spend a minute each morning observing this celestial dance.

RACHEL
It will be a nice way to start your day.

PAUL
That’s Idaho Skies for the 18th and 19th of September.

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.

Monday, September 11, 2017

Idaho Skies Transcript for September 15th, 16th, and 17th

PAUL
Welcome to Idaho Skies for September 15th, 16th, and 17th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Stargazers will have an easy opportunity to see the Beehive star cluster on the morning of the 16th.

RACHEL
The Beehive is one of the few star clusters known to ancient cultures like the Greeks.

PAUL
Of course, without a telescope, they only knew of it as a small fuzzy cloud, or nebula.

RACHEL
In our electrically illuminated world, it’s more difficult to find the Beehive star cluster.

PAUL
Unless of course something brighter points out its location.

RACHEL
This is what happens with the moon on the morning of the 16th.

PAUL
So get out your binoculars and aim them at the moon at around 5:00 AM.

RACHEL
Then shift your binoculars to move the moon to the right edge of your view.

PAUL
Nearly dead center will be a tight grouping of stars.

RACHEL
This is the Beehive star cluster and you could see as many as two dozen stars.

PAUL
Look for the moon before leaving for work on the 17th, and while it’s still dark.

RACHEL
Below the moon is a line of four stars pointing slightly towards the left.

PAUL
First below the moon is the Morning Star, or bright white Venus.

RACHEL
Lower still is slightly yellowish Regulus, the brightest star of the constellation of Leo the Lion.

PAUL
Then very close to the horizon are two stars right next to each other.

RACHEL
The brighter star is Mercury, and it will appear white in color.

PAUL
Just next to it is much fainted Mars.

RACHEL
And it will appear more yellowish-orange than white.

PAUL
But the tint of Mars will be subtle because it’s so faint.

RACHEL
That’s Idaho Skies for the 15th, 16th, and 17th of September.

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.

Idaho Skies Transcript for September 13th and 14th

RACHEL
Welcome to Idaho Skies for September 13th and 14th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Hey, the moon reaches its last quarter phase on the 13th.

PAUL
So astronomers divide the moon into fourths?

RACHEL
Not really. They only divide the moon’s path across the sky into fourths.

PAUL
Every time the moon travels 90 degrees across the sky, the moon enters a new quarter

RACHEL
And the moon’s appearance also takes on a new shape at each quarter.

PAUL
It all starts when the moon is it’s closest to the sun.

RACHEL
The moon is invisible at this time because of the sun’s glare.

PAUL
And because its sets at around the time of sunset.

RACHEL
Roughly, a week later, the moon will travel 90 degrees away from the sun.

PAUL
Sunlight is always illuminating half the moon’s surface.

RACHEL
But only half of that illuminated surface faces directly towards Earth at first quarter.

PAUL
That gives the first quarter moon its half circle shape.

RACHEL
Prior to first quarter, the moon had a crescent shape.

PAUL
That’s because sunlight illuminated most of the lunar farside, or the side we can’t see.

RACHEL
Some people get confused and think the moon’s crescent shape occurs when Earth casts a shadow on it.

PAUL
But it’s actually because we can only see a thin sliver of the moon’s illuminated surface.

RACHEL
As the moon works its away around it, the moon’s illuminated portion also works its way around the surface.

PAUL
Letting stargazers see more the moon in daylight.

RACHEL
And changing the moon from a thin crescent to a fully illuminated moon at full moon.

PAUL
That’s Idaho Skies for the 13th and 14th of September.

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.

Idaho Skies Transcript for September 11th and 12th

PAUL
Welcome to Idaho Skies for September 11th and 12th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Stargazers with binoculars are in for a visual treat on the morning of the 12th.

RACHEL
That’s when the moon passes though the very edge of the Hyades star cluster.

PAUL
The brightest star appearing in the Hyades is Aldebaran and it’s the brightest star in Taurus the Bull.

RACHEL
The moon passes over Aldebaran at 5:46 AM.

PAUL
This is called an occultation and Aldebaran will wink out in a fraction of a second.

RACHEL
So aim your binoculars at the moon at around 5:40 AM.

PAUL
Look for Aldebaran; it’s the star on the moon’s left.

RACHEL
Over the next six minutes, you’ll notice that the moon is creeping ever closer to Aldebaran.

PAUL
It will be a little more difficult to observe the reappearance of Aldebaran.

RACHEL
That’s because it occurs at 7:02 AM in bright dawn.

PAUL
It will be visible, but you definitely need to use your binoculars.

RACHEL
Also on morning of the 12th, Mercury reaches its greatest distance from the sun.

PAUL
So at around 6:30 AM, look in the east for Venus, the Morning Star.

RACHEL
Below it and slightly to the left is the next brightest star, Mercury.

PAUL
Then farther below Mercury is even fainter Mars.

RACHEL
These planets, the terrestrial planets are rocky worlds.

PAUL
And most of them have very little atmosphere.

RACHEL
The atmosphere these planets currently have, originated from within the planet via volcanic action.

PAUL
This means they have atmospheres of primarily nitrogen and carbon dioxide, and not hydrogen and helium.

RACHEL
That’s Idaho Skies for the 11th and 12th of September.

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.

Tuesday, September 5, 2017

Idaho Skies Transcript for September 8th, 9th, and 10th

RACHEL
Welcome to Idaho Skies for September 8th, 9th, and 10th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The solar system’s largest ice giant planet is close to the moon on the 9th.

PAUL
You mean Uranus.

RACHEL
Yep. Did you know Uranus is just barely bright enough to see without optical aid?

PAUL
I did, but I also know it’s difficult to distinguish from all the faint stars in the sky.

RACHEL
That’s why the moon is so helpful to stargazers on the 9th.

PAUL
To see Uranus, drive to a dark location with a friend and your binoculars at around 11:00 PM.

RACHEL
Place the gibbous moon at the right edge of your binoculars, at the 4:00 position.

PAUL
Uranus is the star at the 10:00 position.

RACHEL
And it’s the third brightest star you’ll see in your binoculars.

PAUL
Early risers will see three planets close together in the low east at around 6:15 AM.

RACHEL
Venus or the Morning Star is the brightest one.

PAUL
Below and left of Venus is innermost Mercury.

RACHEL
Mercury is right next to the star, Regulus, but Regulus is the fainter of the two.

PAUL
And below and left of Mercury is even fainter Mars.

RACHEL
How about that, three planets within 14 degrees of each other?

PAUL
That’s close enough that can cover them up with your outstretched hand and thumb.

RACHEL
By the way, the planets aren’t close to each other.

PAUL
Mercury is between Earth and the sun.

RACHEL
Venus is on the other side of the solar system.

PAUL
And tiny Mars is way on the other side of the solar system.

RACHEL
That’s Idaho Skies for the 8th, 9th, and 10th of September.

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.

Idaho Skies Transcript for September 6th and 7th

PAUL
Welcome to Idaho Skies for September 6th and 7th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
The moon is full on the 6th.

RACHEL
Hey, that makes it the Harvest Moon! Shine on, shine ....

PAUL
Uh, no, not quite.

RACHEL
What, why not?

PAUL
The Harvest moon is the first full moon after the autumnal equinox, and not the full moon of September.

RACHEL
Then that means 3 out of 4 full moons in September are not the Harvest Moon.

PAUL
That’s right.

RACHEL
So why do we call the full moon after the autumnal equinox the Harvest Moon?

PAUL
Because the full moon’s path across the sky is nearly level with the eastern horizon in late September.

RACHEL
Okay, so why is that important?

PAUL
Traveling level with the horizon means the moon rises further north every night.

RACHEL
But at nearly the same time?

PAUL
Yep. So at close to the time of sunset the full moon is rising.

RACHEL
And that bright moon light illuminates farm fields late into the night.

PAUL
Before the advent of electric lights, only moon light could illuminate farm fields after sunset.

RACHEL
And that allowed farmers to work late into the night, harvesting their fields.

PAUL
The song, by the way was written in 1908 for the Siegfeld Follies.

RACHEL
And it’s not about harvesting.

PAUL
Nope, it’s about a boy’s girlfriend wanting to go home because she’s afraid of the dark.

RACHEL
And her boyfriend wants to spend more time with her under the willow tree.

PAUL
So he’s asking the Harvest Moon to continue casting its light upon them.

RACHEL
That’s Idaho Skies for the 6th and 7th of September.

 PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.

Idaho skies Transcript for September 4th and 5th

RACHEL
Welcome to Idaho Skies for September 4th and 5th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Quick, what’s the most distant planet in the solar system?

PAUL
Pluto! No wait, it’s Neptune!

RACHEL
That’s right. And Neptune appears next to the moon on the 5th.

PAUL
But isn’t Neptune faint?

RACHEL
Yes it is, so stargazers will need a pair of binoculars or even better, a small telescope to see it.

PAUL
So if a stargazer wants to see Neptune, what does she have to do?

RACHEL
First, travel to someplace with dark skies, but go with a companion for safety.

PAUL
Okay, so I’ll head to the Birds of Prey area.

RACHEL
Bring your binoculars and then aim them at the moon at around 10:00 PM.

PAUL
Got it. The moon is now in the center of my binoculars.

RACHEL
Remember that your binoculars have a field of view that spans 7.5 degrees.

PAUL
Yes they do, because they’re standard 7X50 binoculars.

RACHEL
From the center of the moon, look in the 11:00 position for a star 1.5 degrees away.

PAUL
That’s 1/5th the distance across the binoculars or about three lunar diameters.

RACHEL
Neptune is the only star at that position.

PAUL
And it’s flanked by nearly equally bright stars on its left and right.

RACHEL
Even easier for stargazers to see is the close pairing between Jupiter and Spica.

PAUL
So look in the low west-southwest at 9:00 PM on either the 4th or 5th.

RACHEL
Jupiter is the significantly brighter star on the right.

PAUL
And it’s slightly more yellow than Spica.

RACHEL
That’s Idaho Skies for the 4th and 5th of September.

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

For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.