Transcript for August 25th to 31st

PAUL
Welcome to Idaho Skies for the last week of August. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Did you know that Idaho has a 25” telescope that’s opened to the public?

RACHEL
Twenty five inches is the diameter of the telescope’s mirror.

PAUL
The larger a telescope’s mirror, the more star light it gathers and focuses on your eye.

RACHEL
That means the fainter the objects that you can see through the telescope.

PAUL
The telescope and its observatory are located at the Bruneau Dunes state park.

RACHEL
It’s located there because some of the darkest skies in the Treasure Valley are located at the park.

PAUL
So if you are camping overnight at Bruneau Dunes, consider adding a side trip to the observatory.

RACHEL
Prior to opening the observatory, the park gives a space and astronomy presentation at the Steele Reese Education Center next door to the observatory.

PAUL
The observatory then remains open for several hours

RACHEL
The last quarter moon is next to the Hyades star cluster on the morning of the 28th.

PAUL
Look in the east after midnight to see this grouping.

RACHEL
They’ll be close enough together that the moon and Hyades will fit within your binoculars at the same time.

PAUL
The Pleiades star cluster, which is even more popular than the Hyades, is above the moon and farther away from the moon than the Hyades are.

RACHEL
The waning crescent moon and Jupiter form a nice binocular pair on the morning of the 31st.

PAUL
Recall that this duo passed close to each other on the morning of the 3rd.

RACHEL
This time however, Jupiter and the moon will be a degree closer together.

PAUL
And best of all, they are visible in darker skies.

RACHEL
If you use binoculars to look at Jupiter, you will notice at least two stars to the upper right of Jupiter.

PAUL
These aren’t stars, they’re satellites.

RACHEL
Use a small telescope instead of binoculars and you will see four stars to the upper right of Jupiter.

PAUL
From Jupiter outwards, the satellites are Callisto, Io, Ganymede, and Europa.

RACHEL
Callisto is the largest satellite in the solar system.

PAUL
That’s right. It’s 50% larger than our moon.

RACHEL
When you use your binoculars to observe Jupiter, you are making an observation similar to Galileo’s 1609 observation of Jupiter.

PAUL
Galileo was amazed to see the Jovian moons that we take for granted today.

RACHEL
He would be amazed to see them in the way our visiting spacecraft have.

PAUL
That’s Idaho Skies for the last week of August. Join us next month for the space and astronomical events in Idaho.

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.

Transcript for 18 - 24 August

RACHEL
Welcome to Idaho Skies for the third week of August. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
The moon is full on the 20th. The full moon in August is called the Dog Days or Sturgeon Moon.

PAUL
The full moon means its light will wash out all the fainter stars.

RACHEL
That makes the full moon a bad time to do any star gazing by eye or with binoculars.

PAUL
Did you know Idaho has three planetariums open to the public?

RACHEL
That’s right. The first is located at BYU Idaho in Rexburg.

PAUL
The BYU Idaho planetarium gives presentations every Thursday evening.

RACHEL
Because of summer vacations, August is the only month that they are closed.

PAUL
So keep your eyes open for the resumption of shows next month.

RACHEL
A link to the planetarium can be found on the campus website, www.byui.edu

PAUL
The Wittenberger planetarium at the College of Idaho in Caldwell is the second Idaho planetarium.

RACHEL
The College of Idaho planetarium typically gives shows on the third Wednesday of the month.

PAUL
However, you need to make a reservation in order to attend its presentations.

RACHEL
Call the mathematics and physical sciences department to make your reservation.

PAUL
You’ll find a link to the planetarium at the college of Idaho website, www.collegeofidaho.edu

RACHEL
Idaho’s largest planetarium is located at the College of Southern Idaho campus in Twin Falls.

PAUL
The Faulkner gives more presentations than any other Idaho planetarium.

RACHEL
You’ll find shows on Tuesday and Friday at 2, 3:30, 7, and 8:15 PM.

PAUL
… Wednesday and Thursday at 2 and 3:30 PM.

RACHEL
… and Saturday at 2, 4, 7, and 8:15 PM.

PAUL
This summer the Faulkner planetarium is presenting shows like Light Years from Andromeda, Star Signs, and Lifestyles of the Stars.

RACHEL
You’ll find the Faulkner Planetarium schedule on the College of Southern Idaho website, www.csi.edu.

PAUL
Idaho is also home to three major astronomy clubs.

RACHEL
These include the Boise Astronomical Society, the Magic Valley Astronomical Society, and the Idaho Falls Astronomical Society.

PAUL
Check their respective websites for meeting times and places.

RACHEL
Joining one of these astronomy clubs is a great way to learn about astronomy.

PAUL
That’s Idaho Skies for the third week of August. Next week, the moon passes very close to Jupiter for the second time this month.

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 August 11 - 17

PAUL
Welcome to Idaho Skies for the second week of August. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
The night of the 11th and morning of the 12th is the peak of the Perseid meteor shower.

RACHEL
This meteor shower is best viewed after midnight.

PAUL
That’s when Idaho faces directly into the shower.

RACHEL
It’s similar to driving into a snow storm.

PAUL
That’s right. The rate of snowfall appears to be greater when the car’s direction of travel is into the direction that the snow is falling.

RACHEL
Perseid meteors will appear to radiate from the northeast.

PAUL
Plan to spend some time observing meteors because this shower is very dependable.

RACHEL
You may see more than 30 meteors per hour. And many will be bright and may even flare.

PAUL
136 years ago on the 12th, astronomer Asaph Hall detected a small star-like object close to the planet Mars.

RACHEL
It turned out to be a rock eight miles across orbiting the planet.

PAUL
This was the first Martian satellite that astronomers discovered.

RACHEL
Hall named his discovery Deimos, after one of the twin son’s of the god Mars.

PAUL
The name means terror in Latin.

RACHEL
Because of its small mass, a 12 mile per hour sprint is enough to launch your self off the surface of Deimos and into an eternal orbit around Mars.

PAUL
It wasn’t much later before Hall discovered a second satellite of Mars.

RACHEL
Some people were not surprised to discover that Mars had two satellites.

PAUL
This is because they saw that the two satellites around Mars fit a geometric progression between Earth with one satellite and Jupiter with four satellites.

RACHEL
Jonathon Swift makes mention of this in his story of Gulliver’s Travels.

PAUL
Today we know that Jupiter has far more than four satellites and the fact that Mars has two satellites is just a coincidence.

RACHEL
Speaking of moons, a far less terrifying one appears close to Spica and Saturn on the nights of the 11th and 12th respectively.

PAUL
Both objects will be around three degrees from good ol’ Luna on their night of closest approach.

RACHEL
The best time to look for both of these close approaches is between 10:15 and 10:45 PM.

PAUL
The moon reaches the first quarter phase on the 14th.

RACHEL
As always, this is a great phase for observing the moon with your binoculars or telescope.

PAUL
Focus most of your attention on the terminator, or boundary between day and night, for the greatest amount of visible detail.

RACHEL
The waxing gibbous moon is centered in the Milky Way on the night of the 16th.

PAUL
Search the sky all around the moon with your binoculars and you will find star clusters and nebulas, or clouds of glowing gas.

RACHEL
While binoculars are fine for this, a low power telescope with a wide field of view is even better.

PAUL
Mars passes its closest to Pollux, the brightest star in Gemini on the 17th.

RACHEL
If you have the time, you should start your observations of Mars and Pollux one week earlier.

PAUL
You will notice that Pollux appears higher every morning, but that Mars appears to remain nearly stationary with respect to the horizon.

RACHEL
In time, Earth will begin catching up to Mars.

PAUL
Then Mars will begin appearing in the evening sky rather in the morning sky.

RACHEL
That’s Idaho Skies for the second week of August. Next week we’ll tell you about the planetariums in Idaho. 

PAUL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com. For Idaho Skies this is Paul…

RACHEL
and Rachel.

PAUL
Dark skies and bright stars.

Transcript for August 4 - 10

RACHEL
Welcome to Idaho Skies for the first week of August. We’re your hosts, Rachel…

PAUL
… and Paul.

RACHEL
Our best views of Mercury occur during the first half of the month.

PAUL
That’s because Mercury reached greatest western elongation back on July 30th.

RACHEL
Greatest western elongation occurs when Mercury or Venus reaches its greatest angle away from the sun in the eastern morning sky.

PAUL
Since it just past greatest elongation, Mercury is now approaching closer to the sun.

RACHEL
However, the sun is rising later each morning.

PAUL
That means Mercury’s distance above the horizon prior to sunrise remains nearly unchanged for several days.

RACHEL
Look for Mercury low in the east-northeast for the next two weeks.

PAUL
The moon is just above the star Aldebaran on the morning of the 1st. Many listeners know Aldebaran as the orange eye of Taurus the Bull.

RACHEL
Their separation is just over two degrees, or four lunar diameters. Use your binoculars for observing this pair.

 PAUL
The moon is a waning crescent on the 3rd. This same day, it also makes a close approach to Jupiter.

RACHEL
Jupiter will be obvious as the bright star to the left of the moon. They both will fit within the field of view of your binoculars.

PAUL
On the 4th, the moon passes close to Mars.

RACHEL
Look for them in the low eastern sky in the morning at 5:45 AM.

PAUL
Mars will appear as a yellowish-orange star located to the upper left of the moon.

RACHEL
The very thin crescent moon should display a strong Earthshine.

PAUL
Many people are unfamiliar with Earthshine.

RACHEL
Earthshine is just sunlight reflecting from the moon.

PAUL
However, before the sun’s light reflected off the moon, it first reflected off Earth.

RACHEL
This reflected Earth light faintly illuminates the dark portion of the moon, which is why it is called Earthshine.

PAUL
When you look at the moon, you will see a brightly illuminated crescent surrounding the rest of its faintly illuminated disk.

RACHEL
If you were an astronaut was standing on the Earthshine portion of the moon, it would be dark because the sun had not risen yet.

PAUL
However, overhead would be Earth.

RACHEL
Earth would appear as a nearly full blue-white disk four times larger than the moon appears in our sky and many times brighter.

PAUL
So sunlight reflecting off Earth more brightly illuminates the moon’s surface than the full moon illuminates Earth’s surface.

RACHEL
On the morning of the 8th, Mercury forms a straight line with the stars Castor and Pollux, the brightest stars of Gemini.

PAUL
You’ll need to go outside a little before 6:00 AM and look in the very low east-northeast.

RACHEL
If you go outside much earlier, Mercury will not have risen high enough for you to see.

PAUL
And if you go outside a little after 6:00 AM, the sun will begin brightening the sky too much to see Mercury clearly.

RACHEL
The very thin waxing crescent moon is located five degrees away from Venus on the evening of the 9th.

PAUL
Look low in the west, as the moon is only three days old.

RACHEL
This ought to be an attractive site in your binoculars.

PAUL
That’s Idaho Skies for the first week of August. Next week is one of the year’s best meteor showers.  

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.

This month look for the star Rasalhague in the constellation of Ophiuchus the Serpent Bearer. Rasalhague is the brightest star of this large and dim constellation, which has the shape of a simple house and reaches nearly to the zenith. Ophiuchus is located in the south, just above Scorpius on August evenings and Rasalhague is the star at the top of the constellation.

In Greek myth, Ophiuchus is Asclepius the healer. He was born to a mortal mother and his father was the Greek god Apollo. In his youth, Asclepius was given to Chiron the centaur to raise. It was Chiron who trained his adopted son to be healer. Asclepius became such a great healer that he brought several of his dead patients back to life. To prevent him from going too far, Zeus hurled a thunderbolt and killed Asclepius. His father Apollo complained about the death of his son, so Zeus made Asclepius immortal and placed him in the sky as Ophiuchus.    

Rasalhague (also called Alpha Ophiuchi and 55 Ophiuchi) is Arabic for "the Head of the Serpent Collector."  The star is 47 light years away. Therefore, the light you see from Rasalhague tonight left in 1966. Rasalhague is a double star, but its companion is so close that even a telescope can’t resolve them as separate stars. Rasalhague is spectral type A5 (white in color) and has a surface temperature of 18,000 degrees (compare to 5,800 degrees for the sun). That makes Rasalhague twice as hot and 25 times brighter than our sun. Rasalhague recently (in stellar years) stopped converting hydrogen into helium. Its higher core temperature is permitting the star to generate energy by fusing the helium ash in its core into carbon and oxygen.