RACHEL
Welcome to Idaho Skies for December 23rd, 24th, and 25th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon, Jupiter, and Spica form an astronomical trio on the morning of the 23rd.
PAUL
Earthshine should be easier to see the morning of the 23rd than it was a day ago.
RACHEL
You’ll need to be outside some time between 4:30 AM and 7:00 AM.
PAUL
That’s between the time of moonrise and the break of dawn.
RACHEL
Zubenelgenubi is a double star that appears as a single star to most people.
PAUL
Stargazers with binoculars won’t be tricked however.
RACHEL
That’s because it takes only a little magnification to split the star into two companions.
PAUL
Stargazers can find this double star for themselves on the morning of the 24th.
RACHEL
It’s easier that morning because Zubenelgenubi is the star below the crescent moon at 6:00 AM.
PAUL
You’ll find that the moon and Zubenelgenubi so close enough together, that you can see both at the same time in binoculars.
RACHEL
But just barely.
PAUL
Did you get a telescope on Christmas Eve or very early Christmas morning?
RACHEL
Then put a low power eyepiece into the telescope and point it at the thin crescent moon at 6:00 AM on the 25th.
PAUL
By the way, a low power eyepiece is one with a large focal length.
RACHEL
So a 25 or 50 mm eyepiece would be ideal.
PAUL
Stargazers will see earthshine illuminating the dark portion of the moon.
RACHEL
And sunlit craters nearly edge-on.
PAUL
Their shadows will be cast long...
RACHEL
...but those shadows are pointing towards Earth so we see them strongly foreshortened.
PAUL
That’s Idaho Skies for the 23rd, 24th, and 25th of December.
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, December 19, 2016
Transcript for December 21st and 22nd
PAUL
Welcome to Idaho Skies for December 21st and 22nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Winter begins on the morning of the 21st.
RACHEL
So give a warm welcome to the winter solstice.
PAUL
Wait, solstice?
RACHEL
The word solstice means sun standing still.
PAUL
Standing still?
RACHEL
Sure. It refers to the fact that the sun’s point of rising on the horizon doesn’t appear to shift for several days.
PAUL
Oh I see. Normally, stargazers would notice the sun rises in a more northerly point during the winter and spring.
RACHEL
And rising more southerly point during the summer and fall.
PAUL
So on the first day of winter, that motion temporarily halts.
RACHEL
Hence the name, solstice.
PAUL
Early risers will find three astronomical treats in the low southeast on the morning of the 22nd.
RACHEL
First is a very bright Jupiter below the second treat, the crescent moon.
PAUL
The third treat is a slightly fainter star below Jupiter, the star Spica.
RACHEL
Spica is the brightest star of Virgo the Maiden.
PAUL
Finally, earthshine or the faint illumination on the dark portion of the moon may also be visible that morning.
RACHEL
A pair of binoculars will come in handy for seeing earthshine.
PAUL
Which is actually sunlight, but reflected from Earth first.
RACHEL
That’s Idaho Skies for the 21st and 22nd of December.
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.
Welcome to Idaho Skies for December 21st and 22nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Winter begins on the morning of the 21st.
RACHEL
So give a warm welcome to the winter solstice.
PAUL
Wait, solstice?
RACHEL
The word solstice means sun standing still.
PAUL
Standing still?
RACHEL
Sure. It refers to the fact that the sun’s point of rising on the horizon doesn’t appear to shift for several days.
PAUL
Oh I see. Normally, stargazers would notice the sun rises in a more northerly point during the winter and spring.
RACHEL
And rising more southerly point during the summer and fall.
PAUL
So on the first day of winter, that motion temporarily halts.
RACHEL
Hence the name, solstice.
PAUL
Early risers will find three astronomical treats in the low southeast on the morning of the 22nd.
RACHEL
First is a very bright Jupiter below the second treat, the crescent moon.
PAUL
The third treat is a slightly fainter star below Jupiter, the star Spica.
RACHEL
Spica is the brightest star of Virgo the Maiden.
PAUL
Finally, earthshine or the faint illumination on the dark portion of the moon may also be visible that morning.
RACHEL
A pair of binoculars will come in handy for seeing earthshine.
PAUL
Which is actually sunlight, but reflected from Earth first.
RACHEL
That’s Idaho Skies for the 21st and 22nd of December.
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 December 19th and 20th
RACHEL
Welcome to Idaho Skies for December 19th and 20th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Stargazers going outside after midnight on the 19th will find Leo the Lion sitting on top of the moon.
PAUL
Leo is one of the original 48 constellations recorded by the ancient astronomer Ptolemy.
RACHEL
Ptolemy was a Greek astronomer living in Alexandria, Egypt in the 2nd century AD.
PAUL
Leo was an ancient constellation for Ptolemy because the Mesopotamians recognized it as a lion 4,000 years earlier.
RACHEL
Residing inside the boundary of Leo is a star that astronomer Max Wolf listed as the 359th star in his catalog.
PAUL
He was developing a catalog of stars that were moving quickly across the sky.
RACHEL
This movement is called proper motion and a good way to detect stars that are close to the solar system.
PAUL
Today astronomers call the star Wolf 359.
RACHEL
At a distance of 8 light years, Wolf 359 is the fifth closest star to the solar system.
PAUL
The star appears in several science fiction stories, including Star Trek the Next Generation.
RACHEL
The star is so faint that a large amateur telescope is needed to see it.
PAUL
Why is it so faint if it’s so close to the solar system?
RACHEL
That’s because it’s a low mass red dwarf star.
PAUL
Astronomers discovered early last century that the lower the mass, the fainter the star.
RACHEL
In the case of Wolf 359, it only has 9% of the mass of the sun.
PAUL
That low mass comes with a benefit however.
RACHEL
Astronomers calculate that the star will continue to shine until a ripe old age of 8 trillion years.
PAUL
Which is almost 800 times longer than the sun.
RACHEL
So when the sun is long gone, Wolf 359 won’t even be 1% older.
PAUL
That’s Idaho Skies for the 19th and 20th of December.
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.
Welcome to Idaho Skies for December 19th and 20th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Stargazers going outside after midnight on the 19th will find Leo the Lion sitting on top of the moon.
PAUL
Leo is one of the original 48 constellations recorded by the ancient astronomer Ptolemy.
RACHEL
Ptolemy was a Greek astronomer living in Alexandria, Egypt in the 2nd century AD.
PAUL
Leo was an ancient constellation for Ptolemy because the Mesopotamians recognized it as a lion 4,000 years earlier.
RACHEL
Residing inside the boundary of Leo is a star that astronomer Max Wolf listed as the 359th star in his catalog.
PAUL
He was developing a catalog of stars that were moving quickly across the sky.
RACHEL
This movement is called proper motion and a good way to detect stars that are close to the solar system.
PAUL
Today astronomers call the star Wolf 359.
RACHEL
At a distance of 8 light years, Wolf 359 is the fifth closest star to the solar system.
PAUL
The star appears in several science fiction stories, including Star Trek the Next Generation.
RACHEL
The star is so faint that a large amateur telescope is needed to see it.
PAUL
Why is it so faint if it’s so close to the solar system?
RACHEL
That’s because it’s a low mass red dwarf star.
PAUL
Astronomers discovered early last century that the lower the mass, the fainter the star.
RACHEL
In the case of Wolf 359, it only has 9% of the mass of the sun.
PAUL
That low mass comes with a benefit however.
RACHEL
Astronomers calculate that the star will continue to shine until a ripe old age of 8 trillion years.
PAUL
Which is almost 800 times longer than the sun.
RACHEL
So when the sun is long gone, Wolf 359 won’t even be 1% older.
PAUL
That’s Idaho Skies for the 19th and 20th of December.
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, December 12, 2016
Idaho Skies Transcript for December 16th to 18th
PAUL
Welcome to Idaho Skies for December 16th, 17th, and 18th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon and Beehive star cluster are visible together in binoculars on the night of the 16th.
RACHEL
The Beehive star cluster is one of the few star clusters recorded by ancient civilizations.
PAUL
However, they didn’t know they consisted of stars.
RACHEL
That’s right. They could only see the them as fuzzy patches in the sky.
PAUL
Kind of like an out of focus star.
RACHEL
However, modern stargazers can easily see star clusters like the Beehive with their binoculars.
PAUL
First, aim your binoculars at the moon.
RACHEL
Then place the moon in the lower right edge of your binoculars.
PAUL
As you shift your binoculars, the Beehive star cluster will enter your view from the upper left edge.
RACHEL
Now the moon is going to be bright.
PAUL
That means its light will wash out many of the stars filling the Beehive.
RACHEL
So shift you binoculars away from the moon a bit more until only the Beehive remains.
PAUL
How many stars can you see in the Beehive?
RACHEL
In dark skies, you should see about a dozen stellar members of this cluster.
PAUL
To get an even better view, use averted vision.
RACHEL
That means shift your eyes to look away from the cluster slightly.
PAUL
That way the more sensitive part of your retina is focused on the star cluster.
RACHEL
This is an old trick that stargazers use to detect faint object.
PAUL
But it doesn’t let you see sharp details.
RACHEL
That’s Idaho Skies for the 16th, 17th, and 18th of December.
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.
Welcome to Idaho Skies for December 16th, 17th, and 18th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon and Beehive star cluster are visible together in binoculars on the night of the 16th.
RACHEL
The Beehive star cluster is one of the few star clusters recorded by ancient civilizations.
PAUL
However, they didn’t know they consisted of stars.
RACHEL
That’s right. They could only see the them as fuzzy patches in the sky.
PAUL
Kind of like an out of focus star.
RACHEL
However, modern stargazers can easily see star clusters like the Beehive with their binoculars.
PAUL
First, aim your binoculars at the moon.
RACHEL
Then place the moon in the lower right edge of your binoculars.
PAUL
As you shift your binoculars, the Beehive star cluster will enter your view from the upper left edge.
RACHEL
Now the moon is going to be bright.
PAUL
That means its light will wash out many of the stars filling the Beehive.
RACHEL
So shift you binoculars away from the moon a bit more until only the Beehive remains.
PAUL
How many stars can you see in the Beehive?
RACHEL
In dark skies, you should see about a dozen stellar members of this cluster.
PAUL
To get an even better view, use averted vision.
RACHEL
That means shift your eyes to look away from the cluster slightly.
PAUL
That way the more sensitive part of your retina is focused on the star cluster.
RACHEL
This is an old trick that stargazers use to detect faint object.
PAUL
But it doesn’t let you see sharp details.
RACHEL
That’s Idaho Skies for the 16th, 17th, and 18th of December.
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 December 14th and 15th
RACHEL
Welcome to Idaho Skies for December 14th and 15th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
For stargazers trying to identify Gemini the Twins, your friend is the moon on the 14th.
PAUL
That’s because it passes through the feet of Gemini the Twins that night.
RACHEL
The stars in Gemini form two horizontal rows of stars in the low east at 9:00 PM.
PAUL
The moon will be at located at the right end of the bottom row.
RACHEL
This row represents Pollux, the immortal half of the twins.
PAUL
The row of stars above the moon represents Castor, Pollux’s mortal brother.
RACHEL
In Greek mythology, the mother of Gemini Twins was Leda.
PAUL
But they had different fathers.
RACHEL
The father of Castor was Leda’s husband, Tyndareus, king of Sparta.
PAUL
But the father of Pollux was Zeus, king of the Greek pantheon of gods.
RACHEL
The Gemini Twins are considered protectors of sailors.
PAUL
And they are associated with St. Elmo’s Fire.
RACHEL
For listeners unfamiliar with St. Elmo’s fire, it’s a glowing electrical discharge from sharp-pointed objects.
PAUL
Sailors have observed St. Elmo’s fire emanating from the masts of sailing ships as they sailed through thunderstorms.
RACHEL
It occurs when the voltage difference between the sea and the clouds is great enough to turn the atmosphere around the mast into a plasma.
PAUL
Which is the same thing occurring in fluorescent lights when they glow.
RACHEL
There’s another way to picture Gemini, as the legs of a soccer player.
PAUL
The bright stars of Gemini then represent the hips of the soccer player.
RACHEL
And that means the moon is a soccer ball that Gemini is about to kick on the 14th.
PAUL
That’s Idaho Skies for the 14th and 15th of December.
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.
Welcome to Idaho Skies for December 14th and 15th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
For stargazers trying to identify Gemini the Twins, your friend is the moon on the 14th.
PAUL
That’s because it passes through the feet of Gemini the Twins that night.
RACHEL
The stars in Gemini form two horizontal rows of stars in the low east at 9:00 PM.
PAUL
The moon will be at located at the right end of the bottom row.
RACHEL
This row represents Pollux, the immortal half of the twins.
PAUL
The row of stars above the moon represents Castor, Pollux’s mortal brother.
RACHEL
In Greek mythology, the mother of Gemini Twins was Leda.
PAUL
But they had different fathers.
RACHEL
The father of Castor was Leda’s husband, Tyndareus, king of Sparta.
PAUL
But the father of Pollux was Zeus, king of the Greek pantheon of gods.
RACHEL
The Gemini Twins are considered protectors of sailors.
PAUL
And they are associated with St. Elmo’s Fire.
RACHEL
For listeners unfamiliar with St. Elmo’s fire, it’s a glowing electrical discharge from sharp-pointed objects.
PAUL
Sailors have observed St. Elmo’s fire emanating from the masts of sailing ships as they sailed through thunderstorms.
RACHEL
It occurs when the voltage difference between the sea and the clouds is great enough to turn the atmosphere around the mast into a plasma.
PAUL
Which is the same thing occurring in fluorescent lights when they glow.
RACHEL
There’s another way to picture Gemini, as the legs of a soccer player.
PAUL
The bright stars of Gemini then represent the hips of the soccer player.
RACHEL
And that means the moon is a soccer ball that Gemini is about to kick on the 14th.
PAUL
That’s Idaho Skies for the 14th and 15th of December.
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 December 12th and 13th
PAUL
Welcome to Idaho Skies for December 12th and 13th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
After it gets dark on the 12th, point your binoculars at the moon.
RACHEL
You’ll find it’s slowly drifting through the Hyades star cluster.
PAUL
The brightest star appearing in the Hyades is Aldebaran and it’ll be located to the left of the moon before 8:00 PM.
RACHEL
However, the moon is on the move, so it covers up Aldebaran a short time later.
PAUL
When one astronomical body covers up another, it’s called an occultation.
RACHEL
And the occultation of Aldebaran begins at 8:12 PM on the 12th.
PAUL
You’ll want to start watching a good five minutes earlier.
RACHEL
That way, you have time to locate Aldebaran near the bright moon.
PAUL
Watch Aldebaran carefully, it will wink out before reaching the bright limb of the moon.
RACHEL
The disappearance of Aldebaran will be instantaneous, as the star is only 150 thousandths of a degree across.
PAUL
Its reappearance will be equally abrupt at 9:12 PM.
RACHEL
Except this time, Aldebaran reappears along the bright edge of the lunar limb.
PAUL
The bright edge of the moon will make it more difficult to detect the initial reappearance of Aldebaran.
RACHEL
So carefully watch the upper right edge of the moon before 9:10 PM.
PAUL
Stargazers will find two helpful star charts on the Idaho Skies blog and Twitter account.
RACHEL
The moon is full the next day on the 13th.
PAUL
Or the day it’s opposite the sun in the sky.
RACHEL
Meaning it rises at sunset and sets at sunrise.
PAUL
The full moon in November is called the Cold Moon by some Native American cultures.
RACHEL
That’s Idaho Skies for the 12th and 13th of December.
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.
Welcome to Idaho Skies for December 12th and 13th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
After it gets dark on the 12th, point your binoculars at the moon.
RACHEL
You’ll find it’s slowly drifting through the Hyades star cluster.
PAUL
The brightest star appearing in the Hyades is Aldebaran and it’ll be located to the left of the moon before 8:00 PM.
RACHEL
However, the moon is on the move, so it covers up Aldebaran a short time later.
PAUL
When one astronomical body covers up another, it’s called an occultation.
RACHEL
And the occultation of Aldebaran begins at 8:12 PM on the 12th.
PAUL
You’ll want to start watching a good five minutes earlier.
RACHEL
That way, you have time to locate Aldebaran near the bright moon.
PAUL
Watch Aldebaran carefully, it will wink out before reaching the bright limb of the moon.
RACHEL
The disappearance of Aldebaran will be instantaneous, as the star is only 150 thousandths of a degree across.
PAUL
Its reappearance will be equally abrupt at 9:12 PM.
RACHEL
Except this time, Aldebaran reappears along the bright edge of the lunar limb.
PAUL
The bright edge of the moon will make it more difficult to detect the initial reappearance of Aldebaran.
RACHEL
So carefully watch the upper right edge of the moon before 9:10 PM.
PAUL
Stargazers will find two helpful star charts on the Idaho Skies blog and Twitter account.
RACHEL
The moon is full the next day on the 13th.
PAUL
Or the day it’s opposite the sun in the sky.
RACHEL
Meaning it rises at sunset and sets at sunrise.
PAUL
The full moon in November is called the Cold Moon by some Native American cultures.
RACHEL
That’s Idaho Skies for the 12th and 13th of December.
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.
Monday, December 5, 2016
Transcript for December 9th to 11th
RACHEL
Welcome to Idaho Skies for December 9th, 10th, and 11th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The solar system’s 7th planet is just under 5 degrees from the moon on the 9th.
PAUL
That means stargazers can see it and the moon at the same time through binoculars.
RACHEL
To find Uranus, point your binoculars at the moon on the evening of the 9th.
PAUL
Then shift your view to the upper right until the moon is located in the lower left edge of your field of view.
RACHEL
Uranus will be the star in the upper right edge of the view.
PAUL
You can confirm it’s Uranus if it appears as the lower left corner of a triangle of stars.
RACHEL
For additional confirmation, the star at the top of the triangle will be about twice as bright as Uranus.
PAUL
Stargazers will find a helpful star chart on the Idaho Skies blog and Twitter account.
RACHEL
Stargazers wanting to locate Aries the Ram will appreciate the moon on the 10th.
PAUL
That because it’s located below the constellation that night.
RACHEL
Aries consists of four stars arranged in a slightly curved line.
PAUL
However, only three of them are immediately obvious.
RACHEL
The brightest star of Aries is named Hamal.
PAUL
And it’s the bright star located on the left end of the constellation.
RACHEL
In Greek mythology, Aries represented the Ram with the Golden Fleece.
PAUL
Stargazers should start taking some time to look for Mercury after sunset.
RACHEL
It reaches peak elevation above the horizon in a couple of days.
PAUL
Mercury appears as the only star in the low southwest at 6:00 PM.
RACHEL
Binoculars will help in locating Mercury.
PAUL
But don’t use them until after the sun has set.
RACHEL
That’s Idaho Skies for the 8th, 9th, and 10th of December.
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.
Welcome to Idaho Skies for December 9th, 10th, and 11th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The solar system’s 7th planet is just under 5 degrees from the moon on the 9th.
PAUL
That means stargazers can see it and the moon at the same time through binoculars.
RACHEL
To find Uranus, point your binoculars at the moon on the evening of the 9th.
PAUL
Then shift your view to the upper right until the moon is located in the lower left edge of your field of view.
RACHEL
Uranus will be the star in the upper right edge of the view.
PAUL
You can confirm it’s Uranus if it appears as the lower left corner of a triangle of stars.
RACHEL
For additional confirmation, the star at the top of the triangle will be about twice as bright as Uranus.
PAUL
Stargazers will find a helpful star chart on the Idaho Skies blog and Twitter account.
RACHEL
Stargazers wanting to locate Aries the Ram will appreciate the moon on the 10th.
PAUL
That because it’s located below the constellation that night.
RACHEL
Aries consists of four stars arranged in a slightly curved line.
PAUL
However, only three of them are immediately obvious.
RACHEL
The brightest star of Aries is named Hamal.
PAUL
And it’s the bright star located on the left end of the constellation.
RACHEL
In Greek mythology, Aries represented the Ram with the Golden Fleece.
PAUL
Stargazers should start taking some time to look for Mercury after sunset.
RACHEL
It reaches peak elevation above the horizon in a couple of days.
PAUL
Mercury appears as the only star in the low southwest at 6:00 PM.
RACHEL
Binoculars will help in locating Mercury.
PAUL
But don’t use them until after the sun has set.
RACHEL
That’s Idaho Skies for the 8th, 9th, and 10th of December.
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 December 7th and 8th
PAUL
Welcome to Idaho Skies for December 7th and 8th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon reaches the first quarter phase on the 7th.
RACHEL
First quarter is a good time to take a gander at the moon through binoculars or small telescope.
PAUL
That’s because lots of craters will be visible along the terminator or boundary between the lunar day and night.
RACHEL
However, there will be even more craters scattered across the moon’s southern hemisphere.
PAUL
Lunar craters were discovered by Galileo in 1609.
RACHEL
Prior to that time, most people believed the moon had a smooth and perfect surface.
PAUL
Imagine Galileo’s surprise when he discovered the moon was covered with bowl-like depressions.
RACHEL
He gave the depressions the name crater, which was a shallow bowl used to mix wine and water.
PAUL
More than 60 years ago, it was difficult for people to accept the notion that rocks fell out of the sky.
RACHEL
So lunar craters were originally thought to result from volcanic explosions on the moon.
PAUL
Between World War 1 and World War 2, there was even a suggestion that craters were created by lunar glaciers.
RACHEL
One reason it was difficult to square craters with meteorite impacts is that scientists were unfamiliar with the effects of hypersonic impacts.
PAUL
One person instrumental in getting to the bottom of this in the 1960s was Gene Shoemaker.
RACHEL
He literally did get to the bottom of things by hiking to the bottom of Meteor crater in Arizona.
PAUL
His explorations taught him that the rim of meteor craters are flipped over, but not from a volcanic explosion.
RACHEL
It’s flipped over because a hypersonic impact creates an explosion beneath the ground at the impact site.
PAUL
His observations about craters taught the Apollo astronauts about the lunar terrain before their flights to the moon.
RACHEL
That’s Idaho Skies for the 6th and 7th of December.
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.
Welcome to Idaho Skies for December 7th and 8th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon reaches the first quarter phase on the 7th.
RACHEL
First quarter is a good time to take a gander at the moon through binoculars or small telescope.
PAUL
That’s because lots of craters will be visible along the terminator or boundary between the lunar day and night.
RACHEL
However, there will be even more craters scattered across the moon’s southern hemisphere.
PAUL
Lunar craters were discovered by Galileo in 1609.
RACHEL
Prior to that time, most people believed the moon had a smooth and perfect surface.
PAUL
Imagine Galileo’s surprise when he discovered the moon was covered with bowl-like depressions.
RACHEL
He gave the depressions the name crater, which was a shallow bowl used to mix wine and water.
PAUL
More than 60 years ago, it was difficult for people to accept the notion that rocks fell out of the sky.
RACHEL
So lunar craters were originally thought to result from volcanic explosions on the moon.
PAUL
Between World War 1 and World War 2, there was even a suggestion that craters were created by lunar glaciers.
RACHEL
One reason it was difficult to square craters with meteorite impacts is that scientists were unfamiliar with the effects of hypersonic impacts.
PAUL
One person instrumental in getting to the bottom of this in the 1960s was Gene Shoemaker.
RACHEL
He literally did get to the bottom of things by hiking to the bottom of Meteor crater in Arizona.
PAUL
His explorations taught him that the rim of meteor craters are flipped over, but not from a volcanic explosion.
RACHEL
It’s flipped over because a hypersonic impact creates an explosion beneath the ground at the impact site.
PAUL
His observations about craters taught the Apollo astronauts about the lunar terrain before their flights to the moon.
RACHEL
That’s Idaho Skies for the 6th and 7th of December.
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.
Transcript for December 5th and 6th
RACHEL
Welcome to Idaho Skies for December 5th and 6th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Hey, Neptune is going to be much easier to find on the night of the 6th.
PAUL
That’s because the moon is very close to the planet that night.
RACHEL
In fact, the nearly first quarter moon is only 2 degrees away from Neptune.
PAUL
Stargazers will recall that the field of view of binoculars is five degrees.
RACHEL
So to find Neptune, stargazers need to aim their binoculars at the moon.
PAUL
And then look a bright star just above and left of the moon.
RACHEL
There are two fainter stars forming a slightly bent line to the right of this star.
PAUL
The rightmost star in that bent line is Neptune.
RACHEL
You’ll know its Neptune because it appears brighter than the star in the middle.
PAUL
Another way to confirm you’re looking at Neptune is to put the moon in the center left of your binoculars.
RACHEL
Then Neptune will appear in the center right.
PAUL
Stargazers will find a helpful star chart on the Idaho Skies blog and Twitter account.
RACHEL
After viewing Neptune, put down your binoculars and tell me what you see.
PAUL
Why it’s a bright star way below the moon and near the horizon.
RACHEL
Yep, and the star’s name is Fomalhaut.
PAUL
It’s the brightest star in the constellation of Piscis Austrinus, or the Southern Fish.
RACHEL
Astronomers know it’s a relatively young star because it’s still surrounded in a disk of dust and gas.
PAUL
That’s the dust and gas that the star formed from and what appears to be forming planets now.
RACHEL
The dust is easy to see because Fomalhaut is only 25 light years away from the solar system.
PAUL
That’s Idaho Skies for the 4th and 5th of December.
RACHEL
Be sure to read our blog at idahoskies.blogspot.com for additional information.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for December 5th and 6th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Hey, Neptune is going to be much easier to find on the night of the 6th.
PAUL
That’s because the moon is very close to the planet that night.
RACHEL
In fact, the nearly first quarter moon is only 2 degrees away from Neptune.
PAUL
Stargazers will recall that the field of view of binoculars is five degrees.
RACHEL
So to find Neptune, stargazers need to aim their binoculars at the moon.
PAUL
And then look a bright star just above and left of the moon.
RACHEL
There are two fainter stars forming a slightly bent line to the right of this star.
PAUL
The rightmost star in that bent line is Neptune.
RACHEL
You’ll know its Neptune because it appears brighter than the star in the middle.
PAUL
Another way to confirm you’re looking at Neptune is to put the moon in the center left of your binoculars.
RACHEL
Then Neptune will appear in the center right.
PAUL
Stargazers will find a helpful star chart on the Idaho Skies blog and Twitter account.
RACHEL
After viewing Neptune, put down your binoculars and tell me what you see.
PAUL
Why it’s a bright star way below the moon and near the horizon.
RACHEL
Yep, and the star’s name is Fomalhaut.
PAUL
It’s the brightest star in the constellation of Piscis Austrinus, or the Southern Fish.
RACHEL
Astronomers know it’s a relatively young star because it’s still surrounded in a disk of dust and gas.
PAUL
That’s the dust and gas that the star formed from and what appears to be forming planets now.
RACHEL
The dust is easy to see because Fomalhaut is only 25 light years away from the solar system.
PAUL
That’s Idaho Skies for the 4th and 5th of December.
RACHEL
Be sure to read our blog at idahoskies.blogspot.com for additional information.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
December's Star is Polaris
December’s star is Polaris, or the lucida of Ursa Minor, the Little Bear. Polaris is also known as Alpha Ursae Minoris, the North Star, and the Lode Star. It’s the guide to true north (as opposed to magnetic north) and appears almost straight up to anyone standing on the North Pole. Polaris is not the brightest star in the sky nor is it exactly true north. Polaris is the 40th brightest star in the sky and ¾ of a degree (1-1/2 moon diameters) away from the point of true north in the sky. In long duration photographs, Polaris makes a tiny little circle around the true North Pole. Polaris is an easy star to find since most people can locate the Big Dipper in the sky. The two stars at the end of the Big Dipper’s bowl are called the Pointers. A line drawn up from the Pointers just about runs into Polaris, which is why the stars are called the Pointers. Polaris is the star that marks the end of the Little Dipper’s handle.
Polaris is classified as an F star, which means it’s a bit hotter than our sun. But it’s an old F star, meaning it has started fusing the helium in its core (hydrogen is still being fused, but this takes place in a shell surrounding the core). At 430 light years away, you’re seeing light from Polaris that was emitted in the year 1588.
Idaho Skies Newsletter for December 2016
December 1 – 7
The month opens with brilliant Venus visible in the
Southwest. To the upper left of Venus is far less brilliant Mars shining in its
pale yellow-orange light.
The thin crescent moon appears to the right of Venus on the
evening of the 2nd. The moon is only three days old that night,
meaning earthshine should be easily visible, especially in binoculars.
The moon continues its journey across the sky and passes
close to Mars on the evening of the 4th. Mars will be the pale orange-yellow
star to the moon’s left. Mars will not show detail through binoculars, however,
stargazers will see craters along the edge of the moon.
Put down your binoculars and you’ll see there’s a bright
star way below the moon. The star’s name is Fomalhaut. It belongs to the
constellation of Piscis Austrinus, or the Southern Fish. It’s a relatively
young star and only 25 light years away from the solar system.
The moon reaches the first quarter phase on the 7th.
This is a good time to take a gander at it through your binoculars or small
telescope. Lots of craters will be visible along the terminator or boundary
between day and night. However, most of the craters will be scattered across the
moon’s southern hemisphere.
December 8 – 14
The 7th planet is just under 5 degrees from the
moon on the 9th. That means you can see it and the moon at the same
time through your binoculars, but just barely. To find Uranus, point your
binoculars at the moon and then shift them until the moon is located in the
lower left edge of your field of view. Uranus will be the star in the upper
right edge of the view. You can confirm its Uranus if it appears as the lower
left corner of a triangle of stars. The star at the top of the triangle will be
about twice as bright as Uranus.
Stargazers wanting to locate Aries the
Ram will appreciate the moon on the 10th. That night, the moon is
located below the three brightest stars forming the constellation. The
brightest star of Aries is named Hamal and it’s located on the left end of the
constellation.
Stargazers’ best view of Mercury this
month is the evening of the 12th. Mercury will appear low in the
southwest horizon as its getting dark at 6:00 PM. The low altitude of Mercury
means binoculars will be helpful to stargazers searching for the planet.
Equally important is having a clear and low southwest horizon. Mercury is 4
degrees above the horizon, or just less than the width of a binoculars’ field
of view above the horizon.
After it gets dark on the 12th, point your
binoculars at the moon. You’ll find it’s slowly drifting through the Hyades
star cluster. The majority of the star cluster will be located above and to the
upper right of the moon while Aldebaran, the brightest star in the Hyades, is
located to the left. This makes an attractive sight for binoculars. Even better,
the moon will occult, or cover up Aldebaran a little later.
The occultation of Aldebaran begins on the 12th at
8:12 PM and ends at 9:11 PM. You’ll want to start watching a good five minutes before
the disappearance of Aldebaran so that you won’t miss it. You’ll notice that
the star quickly winks out when it’s covered by the moon. Its reappearance will
be equally abrupt. Since the moon is still not full on the 12th, the
disappearance of Aldebaran will occur along the dark edge of the moon. The
reappearance may be difficult to detect initially since it occurs on the
illuminated hemisphere of the moon. So start watching the upper right edge of
the moon before 9:10 PM to catch Aldebaran’s reappearance.
For beginning new stargazers who are interested in learning
to identify Orion the Hunter, your best opportunity this month is the 13th.
That night, the moon will be located above the constellation. Orion is the tall
rectangle of stars below the moon. You’ll know you’re looking at Orion if you also
see a row of three bright stars forming a horizontal line through the middle of
the rectangle. These stars are nearly the same brightness and represent Orion’s
Belt.
By the way, the moon is also full on the 13th.
The full moon in December is called the Cold Moon.
The moon passes through the feet of Gemini the Twins on the
14th. The stars in Gemini form two horizontal rows of stars and the
moon will be at the right end of the bottom row. That row represents Pollux,
the mortal brother of the twins. Another way to picture Gemini is as the waist
and legs of a soccer player. That makes the moon a soccer ball that Gemini is
about to kick.
December 15 – 21
The moon and Beehive star cluster are visible together in
binoculars on the night of the 16th. To see this very attractive
star cluster, place the moon in the lower right edge of your binoculars. The
Beehive star cluster will then appear at the upper left edge. Shift you
binoculars to Beehive and get the moon out of view for better images of the star
cluster. How many stars can you see in the Beehive?
If you go outside after midnight on the 19th,
you’ll find Leo the Lion sitting on top of the moon. Leo is an old
constellation; it was one of the original 48 constellations recorded by the
ancient astronomer Ptolemy in the 2nd century AD. However, its
history is ancient even for Ptolemy because the Mesopotamians recognized it as
a lion 4,000 years earlier.
The moon is in the last quarter phase on the 20th.
Third quarter means stargazers will need to go outside after midnight to see
it. They’ll be rewarded for their effort by the excellent views of its heavily
cratered southern hemisphere that binoculars will show.
Winter begins on the morning of the 21st. So welcome
winter solstice. The word solstice means sun standing still and refers to the
fact that the sun’s point of rising on the horizon doesn’t appear to shift
north or south for several days. Normally, stargazers notice that the sun rises
in a more northerly point during the winter and spring, and a more southerly
point during the summer and fall. On the first day of winter that motion
temporarily halts, hence the name, solstice.
December 22 – 31
Early risers will find a very bright star
below the crescent moon on the morning of the 22nd. The star won’t
twinkle like other stars because it’s actually the planet Jupiter. The slightly
fainter star below Jupiter is a real star and its name is Spica. Spica is the
brightest star of Virgo the Maiden. Finally, earthshine or the faint
illumination on the dark portion of the moon may also be visible that morning.
A pair of binoculars will come in handy for seeing it. You’ll find the moon in
the low southeast on the morning of the 22nd.
The moon, Jupiter, and Spica form a trio on the morning of
the 23rd. Earthshine should be easier to see that morning than it
was a day ago. You’ll need to go outside after 4:30 AM and before 7:00 AM when the
light of dawn will begin washing out the stars in the east.
Zubenelgenubi is a double star that appears as a single star
to most people. Stargazers with binoculars won’t be tricked however. You can
find this double star for yourself on the morning of the 24th. It’s made
easy because Zubenelgenubi is the star below the crescent moon at 6:00 AM. The
moon and Zubenelgenubi are so close enough together that they can be seen at
the same time in binoculars (just barely). In binoculars, you’ll see that
Zubenelgenubi is really two stars next to each another.
Did you get a telescope on Christmas Eve or Christmas
morning? Then point it at the very thin crescent moon at 6:00 AM on the 25th.
You’ll see earthshine illuminating the dark portion of the moon and craters
nearly edge-on.
It’ll be a little tough, but stargazers can see a very thin
crescent moon on the morning of the 26th. Look very low in the
southeast at 7:00 AM to glimpse the moon in the light of dawn.
The moon is new late on the 28th, so you might be
able to see it when it reappears on the 30th in the evening sky. The
moon will be two days old, which is younger than most people have seen it
without making a serious effort. To see the moon, scan the southwest horizon at
around 6:30 PM. The moon is located to the lower right of brilliant Venus.
If you can’t find the moon on the 30th,
then try again on the 31st. The moon will appear higher above the
southwest horizon at 7:00 PM. The sky is darker, making the moon easier to see
than it was at 6:30 PM a day earlier.
Mars passes 1/12th of a
degree from Neptune on the night of the 31st.
So point your binoculars at Mars, which appears as the yellow-orange star in
the low west-southwest. Once you center Mars in your binoculars, Neptune will be the faint star straight up and slightly
left of Mars. Since they’re only 1/12th of a degree apart, the
distance between Mars and Neptune are only 60th of the way across
your binocular field of view. So we’re talking about them being very close
together.
This Month’s Sources
Astronomical Phenomena of the Year 2016, The Nautical
Almanac Office and Her Majesty’s Nautical Almanac Office
Astronomy Calendar of Celestial Events for Calendar Year
2016, http://www.seasky.org/astronomy/astronomy-calender-2016.html
Night Sky Explorer
Dark Skies and Bright
Stars,
Your
Interstellar Guide
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