RACHEL
Welcome to Idaho Skies for the third week of June. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
It’s amazing what you can do in astronomy using just a stick and a shadow.
PAUL
Yep and here’s one example.
RACHEL
On June 19th, 240 BC, Greek scientist Eratosthenes made the first successful measurement of Earth’s circumference.
PAUL
You’ve probably heard of Eratosthenes, he was the chief librarian in Alexandria, Egypt.
RACHEL
At the library, he learned that at noon on the first day of summer, objects cast no shadow in the town of Syene.
PAUL
Syene is an ancient name for the modern town of Aswan.
RACHEL
...and it’s located south of Alexandria where Eratosthenes lived.
PAUL
Eratosthenes observed that sticks did cast shadows in Alexandria on the same day.
RACHEL
Because sticks cast shadows in Alexandria but not in Syene, Eratosthenes reasoned that Earth must be spherical.
PAUL
So he compared the amount of shadow cast in Alexandria to the distance between Alexandria and Syene.
RACHEL
The amount of shadow indicated the proportion of Earth’s circumference covered by the distance between these two towns.
PAUL
Then he compared the circumference of a complete circle to the portion of Earth’s circumference between Alexandria and Syene.
RACHEL
Based on the ratios, Eratosthenes determined Earth’s circumference to within 16%.
PAUL
So much for the claim that ancients thought the world was flat.
RACHEL
Because the sun casts no shadow at noon on the solstice, Syene must lie on a Tropic.
PAUL
The Tropics are two circles of latitude that are 23.5 degrees north and south of the equator.
RACHEL
Why 23.5 degrees?
PAUL
That’s because Earth’s spin axis is tilted 23.5 degrees with respect to its orbit around the sun.
RACHEL
It means that anyone standing on either circles of latitude must see the sun pass straight overhead on the day of the solstice.
PAUL
The name for the northern circle of latitude is the Tropic of Cancer.
RACHEL
And the southern one is called the Tropic of Capricorn.
PAUL
The names Cancer and Capricorn were chosen because the sun appears in those constellations on the solstices.
RACHEL
These names were given to the tropics about 2,000 years ago
PAUL
And because the Earth’s spin axis slowly wobbles, the sun’s position today on the solstices has shifted by one constellation.
RACHEL
You can’t miss the line formed by Jupiter and Venus on the evening of the 20th.
PAUL
These two bright beacons are just calling for your attention.
RACHEL
Even better, the thin crescent moon appears to their left.
PAUL
Get binoculars out and look for look for Earthshine on the moon and Jupiter’s largest satellites.
RACHEL
That’s Idaho Skies for the third week of June. Next week is the start of Northern summer and we’ll tell you more.
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.
Monday, June 8, 2015
Transcript June 7th to 13th
PAUL
Welcome to Idaho Skies for the second week of June. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
What’s the bright star in the west after dark?
RACHEL
It’s Venus, the Evening Star.
PAUL
This week Venus approaches closer and closer to the Beehive star cluster.
RACHEL
They’re at their closest on the evening of the 12th.
PAUL
Find the Beehive by looking left of Venus with your binoculars.
RACHEL
Each night you’ll see the Beehive closer to Venus.
PAUL
Through binoculars, you’ll see over a dozen stars in the cluster.
RACHEL
And once you see it, you’ll know why people call it the Beehive star cluster.
PAUL
The Space Age has allowed astronomers to determined that Venus is one hellish planet
RACHEL
It’s even worse than Mercury, which has a surface temperature of 800 degrees Fahrenheit.
PAUL
Venus is hotter with a surface temperature of 860 degrees because of its dense atmospheric cloak of carbon dioxide.
RACHEL
Both Earth and Venus developed atmospheres of carbon dioxide after their birth.
PAUL
However, Earth’s carbon dioxide was safely trapped inside of the ocean and rocks like limestone.
RACHEL
Venus on the other hand formed 26 million miles closer to the sun than Earth.
PAUL
And that extra solar heating eventually evaporated its oceans away.
RACHEL
Without oceans, heat from the sun eventually released Venus’ trapped carbon dioxide.
PAUL
Which has created an atmosphere 90 times denser than the Earth’s.
RACHEL
Carbon dioxide is a greenhouse gas that prevents the escape of surface heat into space
PAUL
So even though the clouds of Venus reflect most of the sun’s light, very little heat can actually escape the planet’s atmosphere once it reaches the surface.
RACHEL
In fact, its surface temperature is high enough to melt lead.
PAUL
So it was surprising when 40 years ago on the 8th, the Soviet Union launched the first successful Venus landers.
RACHEL
Venera 9 and 10 spend just short of an hour returning data from the surface of Venus.
PAUL
Including images of its rocky surface.
RACHEL
The amount of sunlight reaching the surface of Venus was surprisingly high.
PAUL
And onboard instruments indicated that the surface was basaltic, like Craters of the Moon.
RACHEL
After an hour on the surface, high heat and pressure fried the Venera landers and their electronics.
PAUL
So today, they lie on the surface slowly eroding away due to exposure to caustic gas and high heat.
RACHEL
That’s Idaho Skies for the second week of June. Some people say that Christopher Columbus proved the world wasn’t flat, but the Greeks knew that almost 2,000 years earlier.
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.
Welcome to Idaho Skies for the second week of June. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
What’s the bright star in the west after dark?
RACHEL
It’s Venus, the Evening Star.
PAUL
This week Venus approaches closer and closer to the Beehive star cluster.
RACHEL
They’re at their closest on the evening of the 12th.
PAUL
Find the Beehive by looking left of Venus with your binoculars.
RACHEL
Each night you’ll see the Beehive closer to Venus.
PAUL
Through binoculars, you’ll see over a dozen stars in the cluster.
RACHEL
And once you see it, you’ll know why people call it the Beehive star cluster.
PAUL
The Space Age has allowed astronomers to determined that Venus is one hellish planet
RACHEL
It’s even worse than Mercury, which has a surface temperature of 800 degrees Fahrenheit.
PAUL
Venus is hotter with a surface temperature of 860 degrees because of its dense atmospheric cloak of carbon dioxide.
RACHEL
Both Earth and Venus developed atmospheres of carbon dioxide after their birth.
PAUL
However, Earth’s carbon dioxide was safely trapped inside of the ocean and rocks like limestone.
RACHEL
Venus on the other hand formed 26 million miles closer to the sun than Earth.
PAUL
And that extra solar heating eventually evaporated its oceans away.
RACHEL
Without oceans, heat from the sun eventually released Venus’ trapped carbon dioxide.
PAUL
Which has created an atmosphere 90 times denser than the Earth’s.
RACHEL
Carbon dioxide is a greenhouse gas that prevents the escape of surface heat into space
PAUL
So even though the clouds of Venus reflect most of the sun’s light, very little heat can actually escape the planet’s atmosphere once it reaches the surface.
RACHEL
In fact, its surface temperature is high enough to melt lead.
PAUL
So it was surprising when 40 years ago on the 8th, the Soviet Union launched the first successful Venus landers.
RACHEL
Venera 9 and 10 spend just short of an hour returning data from the surface of Venus.
PAUL
Including images of its rocky surface.
RACHEL
The amount of sunlight reaching the surface of Venus was surprisingly high.
PAUL
And onboard instruments indicated that the surface was basaltic, like Craters of the Moon.
RACHEL
After an hour on the surface, high heat and pressure fried the Venera landers and their electronics.
PAUL
So today, they lie on the surface slowly eroding away due to exposure to caustic gas and high heat.
RACHEL
That’s Idaho Skies for the second week of June. Some people say that Christopher Columbus proved the world wasn’t flat, but the Greeks knew that almost 2,000 years earlier.
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.
Monday, June 1, 2015
This month's star is Alkaid
Alkaid is a big star that’s four times hotter then the sun and 700 times brighter. It’s hotter and brighter because it has a mass six times greater than our sun’s. Alkaid’s greater mass creates intense pressure that’s crushing its core. The extra compression heats up the core and increases its rate of fusion. On the down side, that extra mass will burn out the star far sooner than our sun.
The Big Dipper is not a constellation. Rather, it’s an asterism, or popular pattern of stars. This means the pattern is not officially recognized by professional astronomers. The Big Dipper is part of a much larger constellation called Ursa Major or the Big Bear. The dipper portion of Ursa Major just represents the bear’s body and a very long tail. The rest of Ursa Major is fainter and not as well known. However, in dark skies you can make out three legs, head, and snout of the bear.
Look for Alkaid tonight almost overhead in the north during June.
Transcript for May 31 to June 6
RACHEL
Welcome to Idaho Skies for the first week of June. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Just after dark on the 1st, you’ll observe Venus in a line with the brightest two stars of Gemini the Twins
PAUL
The stars are named Castor and Pollux.
RACHEL
You’ve probably heard of them before, Castor and Pollux are the twins of Greek mythology.
PAUL
Let Venus show you how to identify Castor and Pollux.
RACHEL
Start by looking in the low west for brilliant Venus.
PAUL
You’ll find the twin stars forming a line on the moon’s right.
RACHEL
Pollux is the brightest of the pair.
PAUL
Later on the 1st, you’ll see the moon and Saturn meet up near Scorpius the Scorpion.
RACHEL
Saturn will be a slightly yellow star located to the moon’s right.
PAUL
The bright star below the moon is orangish Antares, the heart of Scorpius the Scorpion.
RACHEL
After midnight of the 2nd...
PAUL
...actually that’s early morning of the 3rd...
RACHEL
...you can use the moon to find a nice star cluster for your binoculars.
PAUL
Greek astronomer Claudius Ptolemy of Alexandria described this star cluster in the second century AD.
RACHEL
However, it would another 1,500 years before the telescope was invented.
PAUL
Therefore, Ptolemy only identified the star cluster as a little cloud or nebula.
RACHEL
You can find Ptolemy’s little cloud by locating a horizontal pair of stars directly below the moon.
PAUL
The pair represents the stinger of Scorpius and they’re close together.
RACHEL
Place the stinger at the bottom center of your binoculars and then scan to the left.
PAUL
Soon after the stinger leaves your binoculars on the right, the star cluster enters your binoculars on the upper left.
RACHEL
The star cluster will fill about 1/3rd of your binocular’s view.
PAUL
Hey, Venus reaches its greatest distance from the sun on June 6th.
RACHEL
That places the planet at nearly its highest above the horizon after it gets dark.
PAUL
And it’s so high that it won’t set until after midnight.
RACHEL
If you look at Venus through a small telescope before the sky gets dark, you’ll notice that Venus is only half full.
PAUL
And as the weeks pass, the planet will grow larger and thinner.
RACHEL
That’s Idaho Skies for the first week of June. Next week we’ll discuss Venus even further.
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.
Welcome to Idaho Skies for the first week of June. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Just after dark on the 1st, you’ll observe Venus in a line with the brightest two stars of Gemini the Twins
PAUL
The stars are named Castor and Pollux.
RACHEL
You’ve probably heard of them before, Castor and Pollux are the twins of Greek mythology.
PAUL
Let Venus show you how to identify Castor and Pollux.
RACHEL
Start by looking in the low west for brilliant Venus.
PAUL
You’ll find the twin stars forming a line on the moon’s right.
RACHEL
Pollux is the brightest of the pair.
PAUL
Later on the 1st, you’ll see the moon and Saturn meet up near Scorpius the Scorpion.
RACHEL
Saturn will be a slightly yellow star located to the moon’s right.
PAUL
The bright star below the moon is orangish Antares, the heart of Scorpius the Scorpion.
RACHEL
After midnight of the 2nd...
PAUL
...actually that’s early morning of the 3rd...
RACHEL
...you can use the moon to find a nice star cluster for your binoculars.
PAUL
Greek astronomer Claudius Ptolemy of Alexandria described this star cluster in the second century AD.
RACHEL
However, it would another 1,500 years before the telescope was invented.
PAUL
Therefore, Ptolemy only identified the star cluster as a little cloud or nebula.
RACHEL
You can find Ptolemy’s little cloud by locating a horizontal pair of stars directly below the moon.
PAUL
The pair represents the stinger of Scorpius and they’re close together.
RACHEL
Place the stinger at the bottom center of your binoculars and then scan to the left.
PAUL
Soon after the stinger leaves your binoculars on the right, the star cluster enters your binoculars on the upper left.
RACHEL
The star cluster will fill about 1/3rd of your binocular’s view.
PAUL
Hey, Venus reaches its greatest distance from the sun on June 6th.
RACHEL
That places the planet at nearly its highest above the horizon after it gets dark.
PAUL
And it’s so high that it won’t set until after midnight.
RACHEL
If you look at Venus through a small telescope before the sky gets dark, you’ll notice that Venus is only half full.
PAUL
And as the weeks pass, the planet will grow larger and thinner.
RACHEL
That’s Idaho Skies for the first week of June. Next week we’ll discuss Venus even further.
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.
Tuesday, May 26, 2015
Transcript for May 24 - 30
PAUL
Welcome to Idaho Skies for the last week of May. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
You can find the heart of Leo the Lion above the moon on the 24th.
RACHEL
The star’s name is Regulus and it has a diameter about four times larger than the sun.
PAUL
One of the most amazing properties of Regulus is that it rotates once on its axis in just 16 hours.
RACHEL
That’s incredibly fast when you consider that the sun takes 30 days to rotate once.
PAUL
Because Regulus rotates 45 times faster than the sun, its poles are noticeably flattened.
RACHEL
And its equator budges outward.
PAUL
Straight above the moon on the 26th is the second brightest star of Leo the Lion.
RACHEL
The star’s name is Denebola, which means tail in Arabic.
PAUL
Denebola is a guidepost to a large, but sparse star cluster.
RACHEL
So get your binoculars out and trace a straight line from the moon to Denebola.
PAUL
Then extend that line the same distance again.
RACHEL
You’ll run smack dab into a very large and spread out star cluster.
PAUL
The name of the star cluster is MEL-111.
RACHEL
The star cluster is 280 light years away, so the light you see tonight left in the year 1735.
PAUL
There are at least 40 stars in the cluster and you should see at least half of them simultaneously through your binoculars.
RACHEL
You’ll notice that they form a distinctive V shape.
PAUL
The brightest star of Virgo is at the right side of the moon on the 29th.
RACHEL
That’s Spica, right?
PAUL
Yep. Unfortunately, there’s a problem here.
RACHEL
Is it because Virgo is a large and dim constellation?
PAUL
That’s correct. So this leaves Spica in a rather lonely region of the sky.
RACHEL
But have no fear, just look farther to the lower right of the moon.
PAUL
That’s where you’ll see a warped square of four stars.
RACHEL
These stars form the constellation of Corvus the Crow.
PAUL
The star in the upper left corner of Corvus is named Algorab.
RACHEL
That means the crow in Arabic.
PAUL
Look closely at Algorab and you’ll see a second star close to its upper left.
RACHEL
These two stars make Algorab look like a double star.
PAUL
However, they’re actually 30 light years apart and only appear close together in Earth’s sky.
RACHEL
That’s Idaho Skies for the last week of May. Join us next month for the space and astronomy events for Idaho.
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.
Welcome to Idaho Skies for the last week of May. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
You can find the heart of Leo the Lion above the moon on the 24th.
RACHEL
The star’s name is Regulus and it has a diameter about four times larger than the sun.
PAUL
One of the most amazing properties of Regulus is that it rotates once on its axis in just 16 hours.
RACHEL
That’s incredibly fast when you consider that the sun takes 30 days to rotate once.
PAUL
Because Regulus rotates 45 times faster than the sun, its poles are noticeably flattened.
RACHEL
And its equator budges outward.
PAUL
Straight above the moon on the 26th is the second brightest star of Leo the Lion.
RACHEL
The star’s name is Denebola, which means tail in Arabic.
PAUL
Denebola is a guidepost to a large, but sparse star cluster.
RACHEL
So get your binoculars out and trace a straight line from the moon to Denebola.
PAUL
Then extend that line the same distance again.
RACHEL
You’ll run smack dab into a very large and spread out star cluster.
PAUL
The name of the star cluster is MEL-111.
RACHEL
The star cluster is 280 light years away, so the light you see tonight left in the year 1735.
PAUL
There are at least 40 stars in the cluster and you should see at least half of them simultaneously through your binoculars.
RACHEL
You’ll notice that they form a distinctive V shape.
PAUL
The brightest star of Virgo is at the right side of the moon on the 29th.
RACHEL
That’s Spica, right?
PAUL
Yep. Unfortunately, there’s a problem here.
RACHEL
Is it because Virgo is a large and dim constellation?
PAUL
That’s correct. So this leaves Spica in a rather lonely region of the sky.
RACHEL
But have no fear, just look farther to the lower right of the moon.
PAUL
That’s where you’ll see a warped square of four stars.
RACHEL
These stars form the constellation of Corvus the Crow.
PAUL
The star in the upper left corner of Corvus is named Algorab.
RACHEL
That means the crow in Arabic.
PAUL
Look closely at Algorab and you’ll see a second star close to its upper left.
RACHEL
These two stars make Algorab look like a double star.
PAUL
However, they’re actually 30 light years apart and only appear close together in Earth’s sky.
RACHEL
That’s Idaho Skies for the last week of May. Join us next month for the space and astronomy events for Idaho.
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.
Monday, May 18, 2015
Transcript for May 17 to 23
RACHEL
Welcome to Idaho Skies for the third week of May. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon reappears in the evening skies beginning on the 20th.
PAUL
That means it’s a good time to start moon watching.
RACHEL
The moon’s thin crescent will be an attractive sight for your binoculars.
PAUL
And be sure to look for Earthshine on the left side of the moon.
RACHEL
The moon is approaching Venus or the Evening Star later this week.
PAUL
Their closest approach is on the 21st.
RACHEL
Unfortunately, the distance between them is too great to observe both at the same time in binoculars.
PAUL
However, they’ll still worth a peek.
RACHEL
Venus will be located to the right of the crescent moon.
PAUL
In a telescope, you’ll be able to see that Venus is a half crescent shape.
RACHEL
Over the next two months, Venus will grow larger and become a thinner crescent.
PAUL
Venus is so bright that its glare makes it nearly impossible to see its shape clearly after it gets dark
RACHEL
That means the best time to see the shape of Venus is shortly after sunset and before the sky gets dark.
PAUL
Saturn reaches opposition on the 23rd.
RACHEL
At opposition, a planet like Saturn appears opposite the sun in our sky.
PAUL
So look for a slightly creamy-white star in the low south-southeast after it gets dark.
RACHEL
Unlike the surrounding stars, Saturn will not twinkle.
PAUL
Below Saturn, you’ll see a slightly dimmer but orangish star.
RACHEL
The star is Antares, which the Greeks named after the god of war, Ares.
PAUL
The pair makes a nice contrast in color.
RACHEL
The moon approaches so close to Jupiter on the 23rd that you can see both simultaneously in binoculars.
PAUL
Concentrate your attention on Jupiter and you’ll notice that a retinue of moons accompanies it.
RACHEL
Through your binoculars, you should be able to detect Europa on the left side of Jupiter and Callisto on the right side
PAUL
A telescope or spotting scope with higher magnification will reveal the satellite Io located between Europa and Jupiter.
RACHEL
Closer to the moon on the 23rd and located to its right is a star cluster named M-67.
PAUL
Astronomers estimate that this star cluster is 5 billion years old, which makes it slightly older than the sun.
RACHEL
M-67 is visible in binoculars, but appears mostly as a fuzzy spot.
PAUL
That’s Idaho Skies for the third week of May. Next week the moon travels through a lonely part of the sky and we’ll tell you about some of the landmarks you can see.
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.
Welcome to Idaho Skies for the third week of May. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon reappears in the evening skies beginning on the 20th.
PAUL
That means it’s a good time to start moon watching.
RACHEL
The moon’s thin crescent will be an attractive sight for your binoculars.
PAUL
And be sure to look for Earthshine on the left side of the moon.
RACHEL
The moon is approaching Venus or the Evening Star later this week.
PAUL
Their closest approach is on the 21st.
RACHEL
Unfortunately, the distance between them is too great to observe both at the same time in binoculars.
PAUL
However, they’ll still worth a peek.
RACHEL
Venus will be located to the right of the crescent moon.
PAUL
In a telescope, you’ll be able to see that Venus is a half crescent shape.
RACHEL
Over the next two months, Venus will grow larger and become a thinner crescent.
PAUL
Venus is so bright that its glare makes it nearly impossible to see its shape clearly after it gets dark
RACHEL
That means the best time to see the shape of Venus is shortly after sunset and before the sky gets dark.
PAUL
Saturn reaches opposition on the 23rd.
RACHEL
At opposition, a planet like Saturn appears opposite the sun in our sky.
PAUL
So look for a slightly creamy-white star in the low south-southeast after it gets dark.
RACHEL
Unlike the surrounding stars, Saturn will not twinkle.
PAUL
Below Saturn, you’ll see a slightly dimmer but orangish star.
RACHEL
The star is Antares, which the Greeks named after the god of war, Ares.
PAUL
The pair makes a nice contrast in color.
RACHEL
The moon approaches so close to Jupiter on the 23rd that you can see both simultaneously in binoculars.
PAUL
Concentrate your attention on Jupiter and you’ll notice that a retinue of moons accompanies it.
RACHEL
Through your binoculars, you should be able to detect Europa on the left side of Jupiter and Callisto on the right side
PAUL
A telescope or spotting scope with higher magnification will reveal the satellite Io located between Europa and Jupiter.
RACHEL
Closer to the moon on the 23rd and located to its right is a star cluster named M-67.
PAUL
Astronomers estimate that this star cluster is 5 billion years old, which makes it slightly older than the sun.
RACHEL
M-67 is visible in binoculars, but appears mostly as a fuzzy spot.
PAUL
That’s Idaho Skies for the third week of May. Next week the moon travels through a lonely part of the sky and we’ll tell you about some of the landmarks you can see.
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, May 11, 2015
Transcript for May 10 - 16
RACHEL
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Earth passes through the thickest part of a meteor stream on the 5th.
PAUL
Its debris left behind by the famous Comet Halley.
RACHEL
Astronomers call the meteor shower the Eta Aquarids.
PAUL
Welcome to Idaho Skies for the second week of May. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon is approaching new again on the 14th and 15th.
RACHEL
That means these are good mornings to see the thin crescent moon.
PAUL
Look for the moon in the low east as you drive to work at 6:00 AM.
RACHEL
And make sure you look for earthshine on the moon.
PAUL
The light of earthshine will help fill in the dark right side of the moon.
RACHEL
Use your binoculars and you should be able to make out some lunar details in the faint light.
PAUL
Did you know that astronomers discovered Pluto in 1930?
RACHEL
However, it wasn’t until 1978 that astronomers discovered it had a satellite.
PAUL
Then ten years ago on the 15th, astronomers discovered two additional moons of Pluto.
RACHEL
Astronomers named the moons Nix and Hydra.
PAUL
Is that because of New Horizons?
RACHEL
Yep, the N and H in Nix and Hydra were chosen for the N and H in New Horizons.
PAUL
New Horizons is the American spacecraft rapidly approaching Pluto.
RACHEL
Pluto has never been explored by spacecraft.
PAUL
So the New Horizons is our first chance to see this enigmatic world close up.
RACHEL
That means it’s important that New Horizons doesn’t collide with an unknown moon as its approaches Pluto.
PAUL
Because of its ability to detect faint objects, astronomers used the Hubble Space Telescope to search for potentially threatening moons.
RACHEL
In addition to Nix and Hydra, Hubble has also discovered the moons Styx and Kerberos.
PAUL
How could tiny Pluto have five moons?
RACHEL
Astronomers believe Pluto was struck by a passing object early in its history.
PAUL
The whack was similar to the one Earth suffered over four billion years ago.
RACHEL
The impact with Pluto resulted in a debris field orbiting the tiny body.
PAUL
Over time, some debris collapsed back onto to Pluto and the rest coalesced into five new moons.
RACHEL
The largest was Charon, which is about half the size of Pluto.
PAUL
One danger for New Horizons comes from debris that may not have formed a moon.
RACHEL
That’s right; some of it may have formed a dark ring around Pluto.
PAUL
So now, New Horizons is taking images of the Plutonian system in search of possible new hazards.
RACHEL
Don’t forget to mark your calendars for July 14th.
PAUL
That’s when the New Horizons will make a high speed flyby of Pluto.
RACHEL
By the way, Nix is the Greek goddess of the night...
PAUL
...Hydra is a multi-headed serpent-like monster that Hercules killed...
RACHEL
...Styx is the Greek ferryman of the dead...
PAUL
...and Kerberos is the three-headed dog that guards the entrance to Hades.
RACHEL
That’s Idaho Skies for the second week of May. There are planets to see and next week we’ll tell you how to find them.
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.
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Earth passes through the thickest part of a meteor stream on the 5th.
PAUL
Its debris left behind by the famous Comet Halley.
RACHEL
Astronomers call the meteor shower the Eta Aquarids.
PAUL
Welcome to Idaho Skies for the second week of May. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon is approaching new again on the 14th and 15th.
RACHEL
That means these are good mornings to see the thin crescent moon.
PAUL
Look for the moon in the low east as you drive to work at 6:00 AM.
RACHEL
And make sure you look for earthshine on the moon.
PAUL
The light of earthshine will help fill in the dark right side of the moon.
RACHEL
Use your binoculars and you should be able to make out some lunar details in the faint light.
PAUL
Did you know that astronomers discovered Pluto in 1930?
RACHEL
However, it wasn’t until 1978 that astronomers discovered it had a satellite.
PAUL
Then ten years ago on the 15th, astronomers discovered two additional moons of Pluto.
RACHEL
Astronomers named the moons Nix and Hydra.
PAUL
Is that because of New Horizons?
RACHEL
Yep, the N and H in Nix and Hydra were chosen for the N and H in New Horizons.
PAUL
New Horizons is the American spacecraft rapidly approaching Pluto.
RACHEL
Pluto has never been explored by spacecraft.
PAUL
So the New Horizons is our first chance to see this enigmatic world close up.
RACHEL
That means it’s important that New Horizons doesn’t collide with an unknown moon as its approaches Pluto.
PAUL
Because of its ability to detect faint objects, astronomers used the Hubble Space Telescope to search for potentially threatening moons.
RACHEL
In addition to Nix and Hydra, Hubble has also discovered the moons Styx and Kerberos.
PAUL
How could tiny Pluto have five moons?
RACHEL
Astronomers believe Pluto was struck by a passing object early in its history.
PAUL
The whack was similar to the one Earth suffered over four billion years ago.
RACHEL
The impact with Pluto resulted in a debris field orbiting the tiny body.
PAUL
Over time, some debris collapsed back onto to Pluto and the rest coalesced into five new moons.
RACHEL
The largest was Charon, which is about half the size of Pluto.
PAUL
One danger for New Horizons comes from debris that may not have formed a moon.
RACHEL
That’s right; some of it may have formed a dark ring around Pluto.
PAUL
So now, New Horizons is taking images of the Plutonian system in search of possible new hazards.
RACHEL
Don’t forget to mark your calendars for July 14th.
PAUL
That’s when the New Horizons will make a high speed flyby of Pluto.
RACHEL
By the way, Nix is the Greek goddess of the night...
PAUL
...Hydra is a multi-headed serpent-like monster that Hercules killed...
RACHEL
...Styx is the Greek ferryman of the dead...
PAUL
...and Kerberos is the three-headed dog that guards the entrance to Hades.
RACHEL
That’s Idaho Skies for the second week of May. There are planets to see and next week we’ll tell you how to find them.
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.
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