Monday, November 13, 2017

Idaho Skies Transcript for November 24th, 25th, and 26th.

RACHEL
Welcome to Idaho Skies for November 24th, 25th, and 26th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Mercury’s a tiny little squirt as far as planets go.

PAUL
Yep, and it hardly ever appears in our sky.

RACHEL
This planet is only 50% wider than the moon.

PAUL
And it orbits the sun at only 1/3rd the distance that Earth does.

RACHEL
So when Mercury does manage to get far enough away for the sun for us to see, it’s a rare opportunity.

PAUL
Such are the nights around 24th.

RACHEL
Even better, Mercury will have company, Saturn.

PAUL
To see Mercury, look in the low southwest at 6:00 PM on the 24th.

RACHEL
Mercury will be the brightest star really close to the horizon.

PAUL
And Saturn will be half as bright and about three times higher.

RACHEL
Stargazers will probably want to use their binoculars to find elusive little Mercury.

PAUL
But please, don’t start scanning the horizon with them until after the sun has set.

RACHEL
When you do find Mercury, you’ll be looking at a world that looks a lot like the moon on account of its craters.

PAUL
Mercury is so close to the sun that surface temperatures can reach 800 degrees.

RACHEL
Ouch! That’s hot enough to melt lead!

PAUL
Then at night, the temperature drops down to nearly 300 degrees below zero.

RACHEL
Oh well, I guess I won’t recommend Mercury as a vacation spot based on its climate.

PAUL
That’s Idaho Skies for the 24th, 25th and 26th of November.

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 November 22nd and 23rd.

PAUL
Welcome to Idaho Skies for November 22nd and 23rd. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
On our last show, we mentioned that the moon was first visited by spacecraft in 1959 and Saturn was first visited in 1979.

RACHEL
The first spacecraft to visit the moon was Luna 1, a Soviet spacecraft.

PAUL
Luna 1 was humanity’s eighth attempt to send a spacecraft to the moon.

RACHEL
The previous seven either didn’t reach space because the booster rocket exploded...

PAUL
...or because the booster stage performed so poorly that the spacecraft just arced up and then crashed back into Earth’s atmosphere.

RACHEL
Luna 1 was not a completely successful mission, however.

PAUL
That’s right; Soviets engineers intended it to impact the moon.

RACHEL
And instead, it missed the moon by 3,700 miles, or by a distance greater than the moon’s diameter.

PAUL
Saturn on the other hand, had a completely successful first visit.

RACHEL
It was by the American spacecraft Pioneer 11 on September 1st, 1979.

PAUL
Pioneer 11 was the second spacecraft to visit Jupiter and the second to escape the solar system.

RACHEL
The Jet Propulsion Laboratory sent Pioneer 11 to Saturn as a trail blazer.

PAUL
Because it was unknown if the soon to arrive Voyager 1 would survive its passage around Saturn.

RACHEL
So after passing Jupiter, Pioneer 11  was send on a trajectory to closely approach Saturn.

PAUL
Pioneer 11 flew past Saturn at a distance of 12,500 miles and it survived.

RACHEL
And that successful encounter gave mission controllers confidence that Voyager 1 would fly past Saturn safely.

PAUL
That’s Idaho Skies for the 22nd and 23rd of November.

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 November 20th and 21st.

RACHEL
Welcome to Idaho Skies for November 20th and 21st. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Hey moon watchers, the moon reappears on the evening of the 20th.

PAUL
It’s a very thin crescent that evening, so it might be difficult to see.

RACHEL
Especially if there are any obstructions on your southwestern horizon.

PAUL
Helping you find the moon will be Saturn.

RACHEL
So first find Saturn; it’s the faintly tinted star in the low southwest at 6:15 PM.

PAUL
Once you’ve located Saturn, then look for the moon just to the upper right of Saturn.

RACHEL
The moon is only two days old, so it’s younger than most people have ever seen it.

PAUL
That also means you won’t see much detail along the lunar limb in your binoculars.

RACHEL
However, a small telescope might show some craters.

PAUL
What craters are visible will be turned nearly edge-on.

RACHEL
So they’ll appear as very thin ovals.

PAUL
You might be able to detect earthshine on the 20th, if you can see the moon in dark enough skies.

RACHEL
If you don’t see earthshine on the 20th, then try again each evening starting on the 21st.

PAUL
The moon and Saturn are an interesting study in contrasts.

RACHEL
The moon is one-quarter the diameter of Earth and Saturn is nine larger than Earth.

PAUL
The moon is a dry rocky world and Saturn is a gas giant.

RACHEL
The first spacecraft visit to the moon occurred in 1959 and the first spacecraft visit to Saturn occurred in 1979.

PAUL
And of course, Saturn as a beautiful ring whereas the moon has just craters.

RACHEL
That’s Idaho Skies for the 20th and 21st of November.

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

For Idaho Skies this is Rachel...

RACHEL
...and Paul.

PAUL
Dark skies and bright stars.

Idaho Skies Transcript for November 17th, 18th, and 19th

RACHEL
Welcome to Idaho Skies for November 17th, 18th, and 19th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Hey Idaho, let’s go meteor watching this week!

PAUL
The Leonid meteor shower is now at its peak intensity.

RACHEL
This meteor shower consists of cometary dust that’s slamming into the atmosphere at 44 miles per second.

PAUL
That’s faster than most other meteors and it results in a tremendously high kinetic energy for meteoroids.

RACHEL
Therefore, it’s not surprising that the largest Leonid meteoroids can result in spectacularly bright meteors.

PAUL
Look for Leonid meteors as they radiate from the low east after midnight.

RACHEL
And be sure to dress warmly.

PAUL
Stargazers could see upwards of 20 meteors per hour from this shower.

RACHEL
The moon’s new on the 18th.

PAUL
Which is one reason why the Leonids are such a great meteor shower this year.

RACHEL
The new moon means that the moon is passing too close to the sun for us to see it.

PAUL
The moon’s super thin crescent shape and location in the daytime sky makes it’s all but invisible.

RACHEL
Even though it is hiding in plain sight.

PAUL
With impossibly fantastic eyes, you would see the moon five degrees above the sun on the 18th.

RACHEL
Which is ten times the apparent diameter of the sun.

PAUL
So even when the moon is new, it’s still located in the sky.

RACHEL
It’s just too faint to see against an even brighter sky.

PAUL
That’s Idaho Skies for the 17th, 18th, and 19th of November.

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 November 15th and 16th

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

RACHEL
...and Rachel.

PAUL
Mars is currently located on the other side of the solar system.

RACHEL
Since it’s such a small planet, this means it doesn’t appear very bright and might be difficult to locate.

PAUL
Its color, which is pale orange, doesn’t help much when it’s so faint.

RACHEL
In fact, it’s quite easily mistaken for a star right now.

PAUL
So it’s nice of the moon to help stargazers locate this little world.

RACHEL
On the morning of the 15th, look for the very thin crescent moon in the low east-southeast.

PAUL
Mars is the yellowish-orange star to the moon’s upper right.

RACHEL
And the brighter white star below the moon is the star Spica.

PAUL
The distance between Earth and Mars will decrease until mid-summer next year.

RACHEL
That’s when Mars will be an unmistakable reddish-orange beacon in our sky.

PAUL
Mars is not the only planet to look for.

RACHEL
Look of for the moon on the morning of the 16th when it will stand just above Jupiter and Venus.

PAUL
The moon will be an incredibly thin crescent, so you might need binoculars to see it at around 8:00 AM.

RACHEL
However, brilliant Venus will still be easy to spot below the moon.

PAUL
Jupiter will glow with a cooler light between Venus and the moon.

RACHEL
While your binoculars are handy, take a quick peek at Jupiter.

PAUL
You’ll see a star to the planet’s upper right.

RACHEL
That’s Ganymede, the largest satellite in the solar system.

PAUL
That’s Idaho Skies for the 15th and 16th of November.

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 November 13th and 14th

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

PAUL
...and Paul.

RACHEL
Venus and Jupiter are in the process of switching places.

PAUL
Venus has been the Morning Star for months now.

RACHEL
Jupiter was an evening object last summer.

PAUL
At the end of summer, Jupiter approached too close to the sun for Idahoans to see.

RACHEL
Actually, the fault was with Earth, and not in our stars.

PAUL
That’s because Earth travels much faster as it orbits the sun.

RACHEL
So from our perspective, we left Jupiter in the dust.

PAUL
Or at least the sun’s glare.

RACHEL
Now that Jupiter has rounded the sun, it’s reappeared in our morning sky.

PAUL
Again, it’s really due to Earth’s orbital speed being so fast that we’re gaining on Jupiter again.

RACHEL
Since Venus orbits the sun faster than Earth, we can’t keep up.

PAUL
Which makes Venus slowly sink lower and lower in our morning sky.

RACHEL
On the morning of the 13th you’ll see Jupiter just a third of a degree away from Venus.

PAUL
One third of a degree is less than the apparent diameter of the moon.

RACHEL
Or less than 1/20th of a binoculars’ field of view.

PAUL
Since they’re so close, how can a stargazer tell one apart from the other?

RACHEL
Easy, Venus will appear much brighter than Jupiter.

PAUL
Keep an eye on this pair; they’re moving rapidly relative to each other.

RACHEL
That means each morning you’ll easily see the increasing distance between these two planets.

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

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, November 6, 2017

Idaho Skies Transcript for November 10th, 11th, and 12th

PAUL
Welcome to Idaho Skies for November 10th, 11th, and 12th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
The moon reaches the last quarter phase on the 10th.

RACHEL
That means it’s a great time for stargazers to take in a little moon watching.

PAUL
The only negative is that they’ll need to go outside after midnight.

RACHEL
So perhaps stargazers ought to moon watch a few minutes before leaving for work.

PAUL
Concentrate your attention along the terminator, or boundary between the lunar day and night.

RACHEL
That’s where the morning shadows will make lunar features their most visible.

PAUL
Then take another look at the moon on the morning of Saturday the 11th.

RACHEL
That morning, stargazers will see a bright star just to the moon’s left.

PAUL
The star is named Regulus and it’s the brightest of Leo the Lion.

RACHEL
The moon is approaching Regulus, but daylight will prevent Idaho stargazers from seeing the moon occult this star.

PAUL
This next event you won’t miss because of daylight.

RACHEL
From now until the 15th, look in the low east-southeast for the astronomical dance of Venus and Jupiter.

PAUL
Venus is slowly approaching the sun, while Jupiter is rapidly rising higher each morning.

RACHEL
So over the next four days you’ll be able to watch Jupiter climb towards Venus.

PAUL
Then on the 13th, Jupiter will finally appear above Venus.

RACHEL
Jupiter is doing its best to become an evening object.

PAUL
While Venus is doing its best to hide behind the far side of the sun.

RACHEL
That’s Idaho Skies for the 10th, 11th, and 12th of November.

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.