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.

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.

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.

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 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.



Neptune’s much easier to find on the night of the 6th on account of the moon. The nearly first quarter moon is only 2 degrees away from the 8th planet that night. To find Neptune, stargazers need to point their binoculars at the moon and then look a bright star just above and left of the moon. There are two fainter stars to the right of this star that form a line. The last star in that line is Neptune. You can confirm you’re looking at Neptune by the fact that Neptune will be brighter than the star in the middle, but not as bright as the star on the left end of the line. In addition, if you put the moon in the center left of your binoculars, then Neptune will be in the star located in the center right.  



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

Monday, November 28, 2016

Transcript for December 2nd to 4th

RACHEL
Welcome to Idaho Skies for December 2nd, 3rd, and 4th. We’re hosts, Rachel…

PAUL
…and Paul.

RACHEL
The moon is located to the left of Venus on the 2nd.

PAUL
It’s still a very thin crescent, but much easier to see than yesterday.

RACHEL
To see the crescent moon, stargazers need to look in the low southwest at around 6:30, or as soon as it gets dark.

PAUL
Binoculars won’t show much lunar detail yet, there just isn’t enough illuminated moon.

RACHEL
The moon continues its eastward trek and on the 4th, it’s just right of a pale orange star.

PAUL
The star is actually Mars, the solar system’s fourth planet.

RACHEL
Although Mars appears star-like, it’s actually twice the size of the moon.

PAUL
It’s just their distances form Earth that makes them appear this way.

RACHEL
For stargazers curious to know, Mars is 134 million miles away while the moon is only 236 thousand miles away.

PAUL
The surfaces of Both Mars and the moon are rich in basalt, or lava rock.

RACHEL
Why the difference in color if they primarily consist of the same rock type?

PAUL
Well, basalt is a dark gray or black rock, but only as long as it’s not oxidized.

RACHEL
And since the moon has no atmosphere, it remains dark gray to this day.

PAUL
But when the iron in basalt becomes oxidized, it turns rust orange.

RACHEL
Which is the case with Mars, since it has an atmosphere.

PAUL
Well, not much of an atmosphere, but probably a more substantial one billions of years ago.

RACHEL
And planet color may be a good way to tell if an exoplanet is potentially habitatable.

PAUL
That’s Idaho Skies for the 2nd, 3rd, and 4th of December.

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 November 30th and December 1st

PAUL
Welcome to Idaho Skies for November 30th and December 1st. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Take a look at the southeast at 6:15 PM on December 1st.

RACHEL
Brilliant Venus will be easy to see, but can you see the moon?

PAUL
The moon appears as an extremely thin crescent and it’s located to the lower right of Venus.

RACHEL
And that means it’s much closer to the horizon.

PAUL
If you can’t see the moon by eye, then try using your binoculars.

RACHEL
However, don’t start scanning the horizon until after the sun has safely set.

PAUL
It might be difficult to see the moon in the valley considering the mountains on the horizon.

RACHEL
That means that searching for the moon from the Bogus Basin parking might be really helpful.

PAUL
The moon will be 55 hours old on the 1st.

RACHEL
Most people never notice the moon until it closer to 72 hours old.

PAUL
So if you can see it on the 1st, you’ll be part of a select group of humans.

RACHEL
The moon will be easier to see from high elevations.

PAUL
That’s where the air is clearer and the sky darker.

RACHEL
It’s even more helpful if the moon is near perigee, or its closest distance from Earth.

PAUL
Unfortunately, the moon is very close to its apogee, or its greatest distance from Earth on the 1st.

RACHEL
Oh well, there’s always next month.

PAUL
That’s Idaho Skies for the 30th of November and 1st 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.