Tuesday, May 23, 2017

Waning Crescent Moon

I caught a glimpse of the waning crescent moon as I headed to work this morning.


Idaho Skies Transcript for May 26th, 27th, and 28th

PAUL
Welcome to Idaho Skies for May 26th, 27th, and 28th. We’re your hosts, Paul…

RACHEL
…and Rachel.

BRING DOWN MUSIC

PAUL
Sally Ride, the first American woman to travel into space, was born on May 26th, 1951.

RACHEL
Before her flight in the Space Shuttle, only two other women had traveled into space.

PAUL
They were Valentina Tereshkova…

RACHEL
…and Svetlana Savitskaya.

PAUL
Both were Russians, by the way.

RACHEL
And Valentina’s flight was probably just a political stunt by the Soviet Union to beat the United States in space firsts.

PAUL
Sally was selected as a scientist astronaut in 1978.

RACHEL
Her first of two flights occurred when she spent six days onboard the Challenger in June 1983.

PAUL
It was the 7th Space Shuttle flight and the mission deployed two communication satellites.

RACHEL
Sally was one of the Challenger’s mission specialists.

PAUL
And as such, she used the Shuttle’s robotic arm to retrieve experiments deployed from the Shuttle’s cargo bay.

RACHEL
Unfortunately, Sally died in 2012 at an all too young age.

PAUL
Hey stargazers, the moon will be nearly three days old on the 27th.

RACHEL
So seeing it on the evening of the 27th won’t set a record for its earliest sighting.

PAUL
Still, the thin crescent moon will be an attractive sight, especially through binoculars.

RACHEL
Stargazers should also start looking for earthshine illuminating the dark portion of the moon.

FADE IN MUSIC

PAUL
That’s Idaho Skies for the 26th, 27th, and 28th of May.

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 May 24th and 25th

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

PAUL
…and Paul.

BRING DOWN MUSIC

RACHEL
Hey! It’s Towel Day on the 25th!

PAUL
Towel Day? That sounds like something from The Hitchhiker’s Guide to the Galaxy.

RACHEL
It is. On May 25th, 1971, Douglas Adams was traveling through Innsbruck, Austria.

PAUL
And there he got the idea to write a book about hitchhiking through the Milky Way galaxy.

RACHEL
Why a hitchhiking story?

PAUL
Because he was carrying a copy of Ken Welsh’s Hitchhiker’s Guide to Europe.

RACHEL
The Hitchhiker’s Guide to the Galaxy is a classic piece of literature with a certain category of human beings.

PAUL
To the rest of the human population, it’s probably best described as a cult classic.

RACHEL
The novel describes the adventures of one human of the British persuasion, Arthur Dent and his friend, Ford Prefect.

PAUL
By the way, Ford Prefect is from the planet Betelgeuse 5.

RACHEL
One of the pieces of advice given by the Hitchhiker’s Guide is to always know where you towel is.

PAUL
Adams felt that a well organized person would always know where his towel was.

RACHEL
So according to the Guide, having a towel indicates that the hitchhiker must also be in possession of a multitude of other useful items, like a spacesuit.

PAUL
And therefore non-hitchhikers are more likely to lend the hitchhiker anything that he or she may have inadvertently lost.

RACHEL
Like a spacesuit.

PAUL
So don’t forget you towel.

RACHEL
And Don’t Panic.

FADE IN MUSIC

PAUL
That’s Idaho Skies for the 24th and 25th of May.

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 May 22nd and 23rd

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

RACHEL
…and Rachel.

BRING DOWN MUSIC

PAUL
Venus is the Morning Star this month.

RACHEL
In fact, stargazers can’t miss it as they leave for work in the morning.

PAUL
That’s because it’s the brightest star in the low east.

RACHEL
Nothing else can compare to the brilliance of Venus except for the moon and sun.

PAUL
However, on occasion, Jupiter can outshine Venus for short periods of time.

RACHEL
But Jupiter needs to be at opposition and Venus on the other side of the solar system.

PAUL
What makes Venus so bright, other than the fact that it’s close to the sun and Earth?

RACHEL
After the invention of the telescope, astronomers discovered that Venus was shrouded in a thick blanket of very reflective clouds.

PAUL
Since clouds of water are the only thing humans are familiar with, it was originally assumed that the clouds of Venus were also made of water.

RACHEL
Some astronomers even thought the planet might be tropical.

PAUL
Unfortunately, radio observations of Venus in the 1960s indicated that the planet had a temperature of hundreds of degrees.

RACHEL
And it was the Mariner 2 flyby of 1962 that cinched the case; Venus had an atmospheric temperature of 900 degrees.

PAUL
Later space missions determined its clouds consist of sulfur dioxide and droplets of sulfuric acid.

RACHEL
Those sulfur laden clouds create a very reflective surface.

PAUL
In fact, Venus reflects 75% of the sunlight shining upon it.

RACHEL
Compare this to 30% for Earth and 12% for the moon.

PAUL
So it’s no wonder that Venus appears so bright.

FADE IN MUSIC

RACHEL
That’s Idaho Skies for the 22nd and 23rd of May.

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…

RCHEL
…and Rachel.

PAUL
Dark skies and bright stars.

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

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

PAUL
…and Paul.

BRING DOWN MUSIC

RACHEL
The moon’s at last quarter on the 19th.

PAUL
That’s a great phase to go lunar exploring with your binoculars.

RACHEL
However, you’ll need to go outside after midnight to see the moon.

PAUL
Stargazers will notice that the western hemisphere of the moon contains a large lunar maria.

RACHEL
The maria’s name is the Ocean of Storms and it spans over half the circumference of the visible moon.

PAUL
Which makes it the largest maria visible on the moon.

RACHEL
Way beyond the moon is Neptune, a planet too dim to see with the unaided eye.

PAUL
Fortunately, it’s not too dim for binoculars.

RACHEL
However, on account of its faintness, the planet is difficult to find without the aid of a landmark.

PAUL
And this is where the moon comes in handy on the morning of the 20th.

RACHEL
That morning, Neptune appears three degrees to the moon’s upper right.

PAUL
Which is just under half the diameter of a binocular’s field of view.

RACHEL
So to locate Neptune, go outside at around 4:30 AM and point your binoculars at the moon.

PAUL
Then shift your binoculars to the upper right until the moon has just left the field of view.

RACHEL
Neptune will be the brightest star just to the lower left of the center of view.

PAUL
And it will be flanked closely by a second, but slightly fainter star just above it.

FADE IN MUSIC

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

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 May 17th and 18th

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

RACHEL
…and Rachel.

BRING DOWN MUSIC

PAUL
British astronomer Sir Joseph Norman Lockyer was born on May 17th, 1836.

RACHEL
Isn’t he the astronomer who discovered helium?

PAUL
Yes he is.

RACHEL
Here’s the funny thing though, helium wasn’t originally discovered on Earth.

PAUL
Wait, how could Lockyer discover helium if it wasn’t first known on Earth.

RACHEL
Well, He was analyzing the spectrum of the sun when he came across a yellow line.

PAUL
The line was in a location in the spectrum where no known element emitted a yellow line.

RACHEL
So he and another astronomer decided to name the element after the sun god, Helios.

PAUL
Hence the name Helium.

RACHEL
Did you know that all the initial helium in the universe was made over a 20 minute period after the Big Bang?

PAUL
And that it makes up 24% of the universe?

RACHEL
Even though it’s plentiful in the universe, it’s difficult to find on Earth.

PAUL
That’s because Earth’s gravity is too weak to hold on to its supply of helium.

RACHEL
So the largest source of helium on Earth has been the radioactive decay of elements like uranium.

PAUL
The gas gets trapped inside of rock layers beneath the surface.

RACHEL
And when oil drills release gas and oil, the helium escapes to the surface.

PAUL
Where oil companies separate it from the natural gas.

RACHEL
So celebrate the discovery of helium this week.

FADE IN MUSIC

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

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 May 15th and 16th

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

PAUL
…and Paul.

BRING DOWN MUSIC

RACHEL
Williamina Fleming was born 160 years ago on the 15th.

PAUL
What is Ms. Fleming know for?

RACHEL
She was an American astronomer who began her career working at the Harvard College Observatory in 1881.

PAUL
At this time, observatories relied on people to make mathematical calculations of observational data.

RACHEL
These observatory staff were known as computers.

PAUL
One of the thorny problems astronomers were trying to solve in the late 19th century was developing a logical way to classify stars.

RACHEL
So Williamina devised a system of classifying stars by the amount of hydrogen in their spectra.

PAUL
The data she relied on came from observing stars through a spectroscope…

RACHEL
…which is a device that splits the light of stars into specific colors.

PAUL
Star spectrums were recorded on glass photographic plates in the 19th century.

RACHEL
And on account of the poor sensitivity of photographic plates back then, it could take a long time to collect enough light from a spectroscope.

PAUL
Then computers on the observatory staff spent additional hours measuring the location and brightness of the lines in a star’s spectrum.

RACHEL
Over her career, Willimaina classified over 10,000 stars.

PAUL
Including a type of star that was faint, but very hot.

RACHEL
And that was her discovery of the white dwarf star.

FADE IN MUSIC

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

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.