Tuesday, January 16, 2018

Idaho Skies Transcript for January 19th, 20th, and 21st

RACHEL
Welcome to Idaho Skies for January 19th, 20th, and 21st. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Sharp-eyed stargazers will find a two-day old moon on the 19th.

PAUL
Since it’s only two days old, it will be a very thin crescent.

RACHEL
Look in the very low southwest at around 7:00 PM, or as soon as it gets dark.

PAUL
The moon will be so thin that it will be difficult to see lunar detail, even through binoculars.

RACHEL
But binoculars still help you find the moon.

PAUL
The moon will be too close to the horizon to show any earthshine.

RACHEL
So keep an eye on the moon for the next three or so nights in order to see the old moon in the arms of the young.

PAUL
That’s a fancy name for earthshine.

RACHEL
On Friday, be sure to look for a bright star to the moon’s left.

PAUL
You’ll observe Fomalhaut, that lonely star you were seeing in the low south last autumn.

RACHEL
Now for something difficult.

PAUL
If you aim your binoculars at the moon on the 20th, you can see Neptune.

RACHEL
Neptune will be three degrees right of the moon.

PAUL
This means if you center the moon on the left edge of your binoculars, Neptune will be just left of center.

RACHEL
Be careful though, there will be a bright star almost exactly in the center of your view.

PAUL
So look just a little left of that star and back towards the moon.

RACHEL
Neptune will be significantly fainter than the central star, so this observation is best made outside of town.

PAUL
And Neptune will form the corner of a triangle of five stars that are visible in your binoculars.

RACHEL
That’s Idaho Skies for the 19th, 20th, and 21st of January.

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 January 17th and 18th

PAUL
Welcome to Idaho Skies for January 17th and 18th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
The moon is new on the 17th.

RACHEL
That means it’s too close to the sun to see and will set before its gets dark.

PAUL
Perhaps this would be a good time to distinguish between the moon’s far side and the moon’s dark side.

RACHEL
Sure. The lunar far side is the half of the moon we can never see from Earth.

PAUL
And there’s no such thing as the dark side of the moon.

RACHEL
The far side exists because the moon’s day, or the time it takes to rotate once on its axis is 27.3 days.

PAUL
And the length of time it takes the moon to orbit Earth is also 27.3 days.

RACHEL
This means the moon rotates at exactly the rate at which its orbits Earth.

PAUL
The result is that there’s one side of the moon we can never see from Earth.

RACHEL
This is the moon’s far side and it was a mystery until the early Space Age in 1959.

PAUL
Actually, we can manage to see 9% of the moon’s far side.

RACHEL
The reason for this is called libration.

PAUL
One form of libration occurs because the moon’s orbit is elliptical.

RACHEL
This means there are times when the moon is recessing from or approaching Earth.

PAUL
And this allows the moon’s rotation to get a little ahead or behind a line between the centers of the moon and Earth.

RACHEL
A second form occurs because the moon’s orbit is tilted.

PAUL
So at times, the moon is either low or high in its orbit and we can see just peak over the moon’s top or bottom.

RACHEL
Finally, we can just glimpse a bit over the moon’s edge as it rises and sets.

PAUL
That’s Idaho Skies for the 17th and 18th of January.

RACHEL
Be sure to follow us on Twitter @IdahoSkies 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 January 15th and 16th

RACHEL
Welcome to Idaho Skies for January 15th and 16th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Forty-five years ago, the last American Apollo moon landing, Apollo 17, had already returned to Earth.

PAUL
But the Soviet Union wasn’t quite finished with the moon.

RACHEL
On January 16th, their unmanned Luna 21 spacecraft successfully landed on the moon.

PAUL
Its payload was a lunar rover named Lunokhod 2.

RACHEL
This rover was driven by a crew of five back on Earth using three video cameras mounted to the rover.

PAUL
The eight-wheeled Lunokhod 2 weighed 1,800 pounds back on Earth or 300 pounds on the moon.

RACHEL
Lunokhod 2 had a strong resemblance to a crab, with its round body and eight wheels protruding below the body.

PAUL
It was solar powered and those solar cells were mounted to the inside of a lid that covered its body during the cold lunar night.

RACHEL
Over four months, the rover drove a distance of 23.8 miles across the lunar surface, or the nearly the length of a marathon.

PAUL
In that time, it sent over 80,000 television pictures to its operators on Earth.

RACHEL
And it performed tests on soil mechanics, or how strongly the lunar soil or regolith resisted applied forces.

PAUL
In addition, Lunokhod 2 also measured how dark the lunar sky was in attempt to assess the moon’s use as an astronomical site.

RACHEL
Today Lunokhod 2 and its Luna 21 lander have a most unique distinction.

PAUL
They are the only spacecraft, residing on a celestial body that are under private ownership.

RACHEL
Game designer Richard Garriott purchased the pair from a Russian aerospace company for $68,500.

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

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.

Tuesday, January 9, 2018

Idaho Skies Transcript for January 12th, 13th, and 14th

PAUL
Welcome to Idaho Skies for January 12th, 13th, and 14th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Stargazers going outside early in the morning will be able to see earthshine, Mercury, and Saturn this Friday, Saturday, and Sunday.

RACHEL
They’ll also be able to see that Mercury is rapidly approaching the sun.

PAUL
So let’s start on Friday morning at about 7:15 AM.

RACHEL
Stargazers will find the thin crescent moon low in the southeast.

PAUL
And even lower and slight left of the moon will be two planets, Saturn and Mercury.

RACHEL
Mercury and Saturn will be nearly side by side with Mercury being the slightly brighter of the two.

PAUL
Their distance apart will be one degree, or about 1/7th the distance across a binocular’s field of view.

RACHEL
On Saturday morning, stargazers will find the Moon closer to the planets, but now Mercury will be slightly below Saturn.

PAUL
Then on Sunday, the moon will form a straight line with Mercury and Saturn.

RACHEL
Stargazers will also notice that the distance between Mercury and Saturn is significantly wider than it was two days earlier.

PAUL
The reason for the change is the dramatic decrease in the elevation Mercury over two days.

RACHEL
Two days by the way is a bit more than 2% of a Mercurian year, or more than a week of an Earth year.

PAUL
The moon will be an incredibly thin crescent on the 14th.

RACHEL
Because the moon will only be two days from new.

PAUL
That’s younger and thinner than most people have ever seen the moon.

RACHEL
So enjoy watching the Moon, Mercury, and Saturn this weekend.

PAUL
That’s Idaho Skies for the 12th, 13th, and 14th of January.

RACHEL
Be sure to follow us on Twitter @IdahoSkies 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 January 10th and 11th

RACHEL
Welcome to Idaho Skies for January 10th and 11th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Hey! Idahoans are in for an astronomical treat on the morning of the 11th.

PAUL
Go outside by 5:30 AM or a bit later and you’ll find three stars forming a straight line next to the moon’s right side.

RACHEL
Three of these four objects are suitable for binocular viewing, so bring them outside with you.

PAUL
The three stars are actually two planets and one double star.

RACHEL
From the bottom and going up, the objects are Mars...

PAUL
...Jupiter...

RACHEL
...and Zubenelgenubi, which is the faintest of the three.

PAUL
First, take a look at the moon with your binoculars.

RACHEL
Stargazers won’t see that many craters, but they should be able to see earthshine on the moon’s dark portion.

PAUL
You should even see several lunar seas by the light of earthshine.

RACHEL
Next, aim your binoculars at Jupiter.

PAUL
Your binoculars will show two of its moons.

RACHEL
Be sure to brace your binoculars so they remain steady, if you want the clearest images of the moons.

PAUL
The two moons are Ganymede just below Jupiter and Callisto even further below.

RACHEL
Last is Zubenelgenubi, which will appear as a double star through binoculars.

PAUL
And the separation and orientation of the two stars comprising Zubenelgenubi will closely match Jupiter and Callisto.

RACHEL
What about Mars?

PAUL
Unfortunately, it’s too small and far away to show any detail through binoculars.

RACHEL
Finally, Idaho Skies wants to let our listeners to know that the Boise Astronomical Society is holding a free event this week for new telescope owners.

PAUL
If you received a new telescope this Christmas and you need help operating it, visit the society on Friday the 12th at Anser Charter School in Garden City.

RACHEL
Members of the society will be there starting at 7:00 PM to help everyone uncertain with how to operate their telescope.

PAUL
This is a great opportunity to get to know some of the amateur astronomers in our community.

RACHEL
That’s Idaho Skies for the 10th and 11th of January.

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 January 8th and 9th

PAUL
Welcome to Idaho Skies for January 8th and 9th. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
The moon reaches the last quarter phase on the 8th.

RACHEL
Last quarter phase is a good time to view the moon through binoculars, but stargazers will need to go outside after midnight.

PAUL
The moon reaches a third quarter seven days after full because it takes the moon 27.3 days to orbit Earth.

RACHEL
That is, relative to the stars.

PAUL
This 27.3 day orbit is called the synodic month and it was much shorter billions of years ago.

RACHEL
The reason a lunar month takes longer today is because the moon is slowly moving farther away from Earth.

PAUL
Measurements using the laser range finders left on the moon by the Apollo astronauts indicates that the moon moves 1.5 inches farther from Earth each year.

RACHEL
So why is the moon slowly spiraling away from Earth?

PAUL
The main reason is because that the moon’s gravity is raising tides on Earth.

RACHEL
Since Earth spins faster than the moon orbits, the gravity of those tides are pushing the moon ahead and therefore into a higher orbit.

PAUL
But as the moon moves further away from Earth, Earth has to slow down its rotation rate to compensate.

RACHEL
Astronomers predict that in several billion years, the length of Earth’s day and the length of Earth’s month will become equal.

PAUL
When that happens, one day in the future will be weeks long.

RACHEL
When that happens, the moon will remain stationary above one point on Earth.

PAUL
Only that hemisphere of Earth will ever see the moon and there will never be another moon rise.

RACHEL
The question is, will the sun have turned into a red giant and vaporize Earth and the moon before this happens.

PAUL
That’s Idaho Skies for the 8th and 9th of January.

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

For Idaho Skies this is Rachel...

PAUL
...and Paul.

RACHEL
Dark skies and bright stars.

Thursday, December 21, 2017

Free Telescope Workshop for Families with a New Telescope

Are you getting a new telescope for Christmas? Well, the Boise Astronomical Society wants you to enjoy many more successful astronomical encounters with your new telescope. That's why on January 12th, they're hosting a free workshop for families with a new telescope.

The astronomical society understands how difficult it can be to operate a new telescope. So club members will be at Anser Charter School on January 12th starting at 7:00 PM to help anyone with a telescope get the most out of their space explorer.

This is one of many ways your local astronomical club is ready to help our community experience the joy and astronomy. So please pay them a visit - you'll get your best astronomical views this summer if you do.