PAUL
Welcome to Idaho Skies for the fourth week of May. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
May 20th is the 25th anniversary of the launch of Pioneer Venus 1. After entering orbit, it spent a decade exploring Venus.
RACHEL
It used a simple radar system to map the planet’s surface.
PAUL
Thick opaque clouds cover Venus and radar is the only way to penetrate this layer of sulfuric acid clouds.
RACHEL
Spica is the bright star to left of moon on the evening of the 21st.
PAUL
The separation between them is 3½ degrees; therefore, they will both comfortably fit within your binoculars at the same time.
RACHEL
Even though they appear close together, their distance apart in three dimensions is immense.
PAUL
That’s right. It takes light only 1½ seconds to travel the distance between us and the moon. Spica on the other hand requires a trip of 263 years.
RACHEL
On the 22nd, the moon is your guide to Saturn.
PAUL
The ringed planet will appear to the upper left of the moon late that evening.
RACHEL
While the moon is a spectacular binocular and telescope object, Saturn requires a telescope.
PAUL
However, even a small telescope at low power is enough to show the planet’s ring system and largest satellite, Titan.
RACHEL
Another planetary event is taking place on the other side of the sky.
PAUL
For the next week, Jupiter, Venus, and Mercury are approaching one another.
RACHEL
They’re close to the west-northwestern horizon. So you’ll need to look around 9:30 PM. If you find them, all three will fit within your binoculars at the same time.
PAUL
And their configuration will get more tightly grouped over the next four days.
RACHEL
Five years ago on the 25th, the Phoenix lander arrived on Mars.
PAUL
The mission of the Phoenix lander was to explore the role and history of water on the Martian surface.
RACHEL
Its landing site was located in the arctic region of Mars where scientists believed water would accumulate as ice.
PAUL
A camera on the lander showed that its landing engines blew loose dust off of a layer of ice buried just beneath the Martian soil.
RACHEL
What appears to be water drops, were seen clinging to the landing legs before they eventually sublimated away.
PAUL
No one expected to see drops of liquid water on Mars, as its atmospheric pressure is far too low for water to exist in the liquid phase.
RACHEL
One reason that water might be able to exist for a short time as a liquid is that the Martian artic soil contains a perchlorate salt.
PAUL
Perchlorate can act as antifreeze and that makes liquid water a little more stable in extreme conditions.
RACHEL
Signs gathered by this lander and other spacecraft now indicate that the planet once had a wetter climate.
PAUL
That’s Idaho Skies for the fourth week of May. Join us next week to hear about two great opportunities to observe four planets.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Sunday, May 19, 2013
Transcript for May 12 to 18
RACHEL
Welcome to Idaho Skies for the third week of May. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is making an evening appearance this week.
PAUL
It takes two or three days after new moon for it to get far enough away from the sun that we can easily observe it after dusk.
RACHEL
On the evening of the 12th, the moon will be a crescent and just to the left of Jupiter. Both will be close enough together to be seen at the same time in your binoculars.
PAUL
Try looking for them around 10 PM.
RACHEL
You might notice a star very close to the moon on the right.
PAUL
That’s the star Zeta Tauri, which is 418 light years away.
RACHEL
Do you want to learn to identify the constellation of Gemini?
PAUL
The celestial twins stand on top of the moon on the 13th.
RACHEL
Gemini will appear as two parallel columns of stars stretching to the upper right of the moon.
PAUL
Some of our listeners may remember when the United States launched its first space station, Skylab.
RACHEL
The day was May 14th, 1974. Initially, the launch seemed to go well.
PAUL
The outer surface of Skylab acted as a micrometeoroid shield. Engineers designed it to extend a little distance away from the main body of the space station after it entered orbit.
RACHEL
Unfortunately, the shield deployed from the space station during its ascent to orbit.
PAUL
This permitted the rush of the atmosphere to rip it and one of Skylab’s solar arrays off the space station.
RACHEL
Because of the repairs performed by the first crew of astronauts to visit Skylab, the mission of the space station was able to continue.
PAUL
Among their experiments, astronauts made observations of the sun with an array of several telescopes.
RACHEL
Because the Space Shuttle launched several years later than planned, Skylab was not rescued and refurbished before reentering the atmosphere in July 1979.
PAUL
The oldest star cluster easily visible to our eye through binoculars is M-67 in Cancer the Crab.
RACHEL
The stars in this cluster are about four billion years old, or a little younger than our solar system.
PAUL
On the evening of the 16th, the moon is your guide to this cluster.
RACHEL
Use binoculars and search for a hazy spot to the right of the moon.
PAUL
The cluster spans an angle close to the moon’s size.
RACHEL
The heart of Leo the Lion is the star Regulus.
PAUL
It’s the yellowish-orange star above the first quarter moon on the night of the 17th.
RACHEL
While it doesn’t look like much to our eye, Regulus is quite a large star. It has a diameter five times greater than the sun’s and spins much faster.
PAUL
And we mean fast. Regulus rotates once in 16 hours versus the 24 days it takes our sun to rotate once.
RACHEL
Because of its large girth and short rotational period, the surface of Regulus travels at nearly 70,000 miles per hour at its equator.
PAUL
That high speed creates a budge at the equator. The bulge makes Regulus 33% wider across its equator than across its poles.
RACHEL
That’s Idaho Skies for the third week of May. Next week, you can locate Saturn and the star Spica next week with a little help from the moon.
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 third week of May. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is making an evening appearance this week.
PAUL
It takes two or three days after new moon for it to get far enough away from the sun that we can easily observe it after dusk.
RACHEL
On the evening of the 12th, the moon will be a crescent and just to the left of Jupiter. Both will be close enough together to be seen at the same time in your binoculars.
PAUL
Try looking for them around 10 PM.
RACHEL
You might notice a star very close to the moon on the right.
PAUL
That’s the star Zeta Tauri, which is 418 light years away.
RACHEL
Do you want to learn to identify the constellation of Gemini?
PAUL
The celestial twins stand on top of the moon on the 13th.
RACHEL
Gemini will appear as two parallel columns of stars stretching to the upper right of the moon.
PAUL
Some of our listeners may remember when the United States launched its first space station, Skylab.
RACHEL
The day was May 14th, 1974. Initially, the launch seemed to go well.
PAUL
The outer surface of Skylab acted as a micrometeoroid shield. Engineers designed it to extend a little distance away from the main body of the space station after it entered orbit.
RACHEL
Unfortunately, the shield deployed from the space station during its ascent to orbit.
PAUL
This permitted the rush of the atmosphere to rip it and one of Skylab’s solar arrays off the space station.
RACHEL
Because of the repairs performed by the first crew of astronauts to visit Skylab, the mission of the space station was able to continue.
PAUL
Among their experiments, astronauts made observations of the sun with an array of several telescopes.
RACHEL
Because the Space Shuttle launched several years later than planned, Skylab was not rescued and refurbished before reentering the atmosphere in July 1979.
PAUL
The oldest star cluster easily visible to our eye through binoculars is M-67 in Cancer the Crab.
RACHEL
The stars in this cluster are about four billion years old, or a little younger than our solar system.
PAUL
On the evening of the 16th, the moon is your guide to this cluster.
RACHEL
Use binoculars and search for a hazy spot to the right of the moon.
PAUL
The cluster spans an angle close to the moon’s size.
RACHEL
The heart of Leo the Lion is the star Regulus.
PAUL
It’s the yellowish-orange star above the first quarter moon on the night of the 17th.
RACHEL
While it doesn’t look like much to our eye, Regulus is quite a large star. It has a diameter five times greater than the sun’s and spins much faster.
PAUL
And we mean fast. Regulus rotates once in 16 hours versus the 24 days it takes our sun to rotate once.
RACHEL
Because of its large girth and short rotational period, the surface of Regulus travels at nearly 70,000 miles per hour at its equator.
PAUL
That high speed creates a budge at the equator. The bulge makes Regulus 33% wider across its equator than across its poles.
RACHEL
That’s Idaho Skies for the third week of May. Next week, you can locate Saturn and the star Spica next week with a little help from the moon.
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.
Sunday, May 12, 2013
Transcript for May 5 to May 11
PAUL
Welcome to Idaho Skies for the second week of May. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The Eta Aquarid meteor shower reaches its peak on the 5th.
RACHEL
This meteor shower is visible for at least a week before and after its peak, which is good because the moon’s light is going to interfere.
PAUL
The moon’s light is not the only strike against this shower.
RACHEL
That’s right. It’s radiant, or the point in the sky where the meteors appear to radiate from, is close to the horizon in the Northern hemisphere.
PAUL
This means the meteor shower is much better south of the equator.
RACHEL
Did you know that the parent of the Eta Aquarid meteor shower is comet Halley?
PAUL
The Eta Aquarids is one of the two showers that originate from this comet.
RACHEL
So if you observe meteors from this shower this week, you’re watching dust from comet Halley vaporizing dozens of miles overhead.
PAUL
In dark skies and with no moon, you can expect to see around ten swift meteors per hour from this shower.
RACHEL
You’ll know you’ve seen an Eta Aquarid meteor if it originated from the low east.
PAUL
Even neater, a sizable portion of these meteors are expected to leave trains.
RACHEL
Meteor trains are the glowing trails left behind a meteor’s passage through the atmosphere. They can last from a few seconds to several minutes.
PAUL
Astronomers do not fully understand the mechanism responsible for meteor trains. However, they know that some of it consists of energetic atoms.
RACHEL
The high energy of the atoms and ions in the meteor train cause them to glow.
PAUL
If you see a long lasting meteor train, you may notice that its shape changes over time. Part of the reason is that high altitude winds are blowing the train in different directions
RACHEL
The moon is new on the 9th.
PAUL
At new moon, the moon’s orbital path carries the moon closest to the sun.
RACHEL
Since the moon’s orbit is tipped five degrees relative to Earth’s equator, the moon often passes over or below the sun at new.
PAUL
If there were no tilt in the moon’s orbit, then every new moon would result in a solar eclipse.
RACHEL
Fortunately, this month, the moon will indeed pass in front of the sun. The solar eclipse will only be visible in Australia, however.
PAUL
The moon will be 24 hours old on the evening of the 10th.
RACHEL
It will be difficult to see, but this is an opportunity to search for a very young crescent moon.
PAUL
Use binoculars and look just left, or south of Venus, very low in the northwestern sky right after sunset.
RACHEL
If you can find the moon, it will be just a sliver and will not even span half a circle.
PAUL
That’s Idaho Skies for the second week of May. Next week the young crescent moon leads us to a very old star cluster visible in binoculars.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com. For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for the second week of May. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The Eta Aquarid meteor shower reaches its peak on the 5th.
RACHEL
This meteor shower is visible for at least a week before and after its peak, which is good because the moon’s light is going to interfere.
PAUL
The moon’s light is not the only strike against this shower.
RACHEL
That’s right. It’s radiant, or the point in the sky where the meteors appear to radiate from, is close to the horizon in the Northern hemisphere.
PAUL
This means the meteor shower is much better south of the equator.
RACHEL
Did you know that the parent of the Eta Aquarid meteor shower is comet Halley?
PAUL
The Eta Aquarids is one of the two showers that originate from this comet.
RACHEL
So if you observe meteors from this shower this week, you’re watching dust from comet Halley vaporizing dozens of miles overhead.
PAUL
In dark skies and with no moon, you can expect to see around ten swift meteors per hour from this shower.
RACHEL
You’ll know you’ve seen an Eta Aquarid meteor if it originated from the low east.
PAUL
Even neater, a sizable portion of these meteors are expected to leave trains.
RACHEL
Meteor trains are the glowing trails left behind a meteor’s passage through the atmosphere. They can last from a few seconds to several minutes.
PAUL
Astronomers do not fully understand the mechanism responsible for meteor trains. However, they know that some of it consists of energetic atoms.
RACHEL
The high energy of the atoms and ions in the meteor train cause them to glow.
PAUL
If you see a long lasting meteor train, you may notice that its shape changes over time. Part of the reason is that high altitude winds are blowing the train in different directions
RACHEL
The moon is new on the 9th.
PAUL
At new moon, the moon’s orbital path carries the moon closest to the sun.
RACHEL
Since the moon’s orbit is tipped five degrees relative to Earth’s equator, the moon often passes over or below the sun at new.
PAUL
If there were no tilt in the moon’s orbit, then every new moon would result in a solar eclipse.
RACHEL
Fortunately, this month, the moon will indeed pass in front of the sun. The solar eclipse will only be visible in Australia, however.
PAUL
The moon will be 24 hours old on the evening of the 10th.
RACHEL
It will be difficult to see, but this is an opportunity to search for a very young crescent moon.
PAUL
Use binoculars and look just left, or south of Venus, very low in the northwestern sky right after sunset.
RACHEL
If you can find the moon, it will be just a sliver and will not even span half a circle.
PAUL
That’s Idaho Skies for the second week of May. Next week the young crescent moon leads us to a very old star cluster visible in binoculars.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com. For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Transcript for May 12 to May 19
RACHEL
Welcome to Idaho Skies for the third week of May. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is making an evening appearance this week.
PAUL
It takes two or three days after new moon for it to get far enough away from the sun that we can easily observe it after dusk.
RACHEL
On the evening of the 12th, the moon will be a crescent and just to the left of Jupiter. Both will be close enough together to be seen at the same time in your binoculars.
PAUL
Try looking for them around 10 PM.
RACHEL
You might notice a star very close to the moon on the right.
PAUL
That’s the star Zeta Tauri, which is 418 light years away.
RACHEL
Do you want to learn to identify the constellation of Gemini?
PAUL
The celestial twins stand on top of the moon on the 13th.
RACHEL
Gemini will appear as two parallel columns of stars stretching to the upper right of the moon.
PAUL
Some of our listeners may remember when the United States launched its first space station, Skylab.
RACHEL
The day was May 14th, 1974. Initially, the launch seemed to go well.
PAUL
The outer surface of Skylab acted as a micrometeoroid shield. Engineers designed it to extend a little distance away from the main body of the space station after it entered orbit.
RACHEL
Unfortunately, the shield deployed from the space station during its ascent to orbit.
PAUL
This permitted the rush of the atmosphere to rip it and one of Skylab’s solar arrays off the space station.
RACHEL
Because of the repairs performed by the first crew of astronauts to visit Skylab, the mission of the space station was able to continue.
PAUL
Among their experiments, astronauts made observations of the sun with an array of several telescopes.
RACHEL
Because the Space Shuttle launched several years later than planned, Skylab was not rescued and refurbished before reentering the atmosphere in July 1979.
PAUL
The oldest star cluster easily visible to our eye through binoculars is M-67 in Cancer the Crab.
RACHEL
The stars in this cluster are about four billion years old, or a little younger than our solar system.
PAUL
On the evening of the 16th, the moon is your guide to this cluster.
RACHEL
Use binoculars and search for a hazy spot to the right of the moon.
PAUL
The cluster spans an angle close to the moon’s size.
RACHEL
The heart of Leo the Lion is the star Regulus.
PAUL
It’s the yellowish-orange star above the first quarter moon on the night of the 17th.
RACHEL
While it doesn’t look like much to our eye, Regulus is quite a large star. It has a diameter five times greater than the sun’s and spins much faster.
PAUL
And we mean fast. Regulus rotates once in 16 hours versus the 24 days it takes our sun to rotate once.
RACHEL
Because of its large girth and short rotational period, the surface of Regulus travels at nearly 70,000 miles per hour at its equator.
PAUL
That high speed creates a budge at the equator. The bulge makes Regulus 33% wider across its equator than across its poles.
RACHEL
That’s Idaho Skies for the third week of May. Next week, you can locate Saturn and the star Spica next week with a little help from the moon.
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 third week of May. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is making an evening appearance this week.
PAUL
It takes two or three days after new moon for it to get far enough away from the sun that we can easily observe it after dusk.
RACHEL
On the evening of the 12th, the moon will be a crescent and just to the left of Jupiter. Both will be close enough together to be seen at the same time in your binoculars.
PAUL
Try looking for them around 10 PM.
RACHEL
You might notice a star very close to the moon on the right.
PAUL
That’s the star Zeta Tauri, which is 418 light years away.
RACHEL
Do you want to learn to identify the constellation of Gemini?
PAUL
The celestial twins stand on top of the moon on the 13th.
RACHEL
Gemini will appear as two parallel columns of stars stretching to the upper right of the moon.
PAUL
Some of our listeners may remember when the United States launched its first space station, Skylab.
RACHEL
The day was May 14th, 1974. Initially, the launch seemed to go well.
PAUL
The outer surface of Skylab acted as a micrometeoroid shield. Engineers designed it to extend a little distance away from the main body of the space station after it entered orbit.
RACHEL
Unfortunately, the shield deployed from the space station during its ascent to orbit.
PAUL
This permitted the rush of the atmosphere to rip it and one of Skylab’s solar arrays off the space station.
RACHEL
Because of the repairs performed by the first crew of astronauts to visit Skylab, the mission of the space station was able to continue.
PAUL
Among their experiments, astronauts made observations of the sun with an array of several telescopes.
RACHEL
Because the Space Shuttle launched several years later than planned, Skylab was not rescued and refurbished before reentering the atmosphere in July 1979.
PAUL
The oldest star cluster easily visible to our eye through binoculars is M-67 in Cancer the Crab.
RACHEL
The stars in this cluster are about four billion years old, or a little younger than our solar system.
PAUL
On the evening of the 16th, the moon is your guide to this cluster.
RACHEL
Use binoculars and search for a hazy spot to the right of the moon.
PAUL
The cluster spans an angle close to the moon’s size.
RACHEL
The heart of Leo the Lion is the star Regulus.
PAUL
It’s the yellowish-orange star above the first quarter moon on the night of the 17th.
RACHEL
While it doesn’t look like much to our eye, Regulus is quite a large star. It has a diameter five times greater than the sun’s and spins much faster.
PAUL
And we mean fast. Regulus rotates once in 16 hours versus the 24 days it takes our sun to rotate once.
RACHEL
Because of its large girth and short rotational period, the surface of Regulus travels at nearly 70,000 miles per hour at its equator.
PAUL
That high speed creates a budge at the equator. The bulge makes Regulus 33% wider across its equator than across its poles.
RACHEL
That’s Idaho Skies for the third week of May. Next week, you can locate Saturn and the star Spica next week with a little help from the moon.
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.
Saturday, April 27, 2013
Transcript for April 28 - May 4
RACHEL
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel…
PAUL
… and Paul.
RACHEL
The moon is at third quarter on the 2nd.
PAUL
First and third quarter moons are half moons.
RACHEL
The first quarter is the half moon most people see after sunset in the south.
PAUL
Sunlight illuminates the right half of the moon, or the moon’s eastern hemisphere.
RACHEL
At the third quarter moon, the sun illuminates the moon’s western hemisphere. Unlike the first quarter moon, the third quarter moon doesn’t rise until around midnight.
PAUL
The first and third quarter moons are excellent astronomical objects for binoculars and small telescopes.
RACHEL
That’s because the terminator of the first and third quarter moons point directly towards Earth.
PAUL
As a result, the shadows on the face of the moon are stretched their longest from our perspective.
RACHEL
One thing you will notice about the third quarter moon is that the western hemisphere of the moon is covered in more extensive maria than the eastern hemisphere.
PAUL
The maria are vast lava flows that filled ancient impact basins.
RACHEL
This occurred around 3.9 billion years ago when the moon’s interior was still hot.
PAUL
The flooding occurred in waves so each eruption left a thin layer of lava covering the previous eruption.
RACHEL
When you look at the lunar maria though your binoculars, you’ll see layers of rock older than any rocks on Earth.
PAUL
The moon’s largest impact basin is 1,500 miles across and eight miles deep in places. That’s large enough to span one quarter of the moon.
RACHEL
The impact basin is located between the crater Aitken and the moon’s South Pole.
PAUL
Astronomers named this impact basin the South Pole-Aitken basin and it’s the moon’s oldest recognized impact basin.
RACHEL
Because the impact basin is located at the Moon’s South Pole, we were unaware of its existence until spacecraft began exploring the moon in the early 1960s.
PAUL
It wasn’t until the 1990s that scientists mapped the complete topography of the South Pole-Aitken basin, and discovered that it is one of the solar system’s largest impact basins.
RACHEL
May 3rd is Space Day.
PAUL
Space Day is a celebration of humanity’s exploration of outer space. It is sponsored by the aerospace company Lockheed Martin.
RACHEL
Check out the Space Day website to see if anything is happening near you. www.spaceday.org
PAUL
That’s Idaho Skies for the first week of May. Join us next week to hear about Idaho’s next meteor shower.
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.
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel…
PAUL
… and Paul.
RACHEL
The moon is at third quarter on the 2nd.
PAUL
First and third quarter moons are half moons.
RACHEL
The first quarter is the half moon most people see after sunset in the south.
PAUL
Sunlight illuminates the right half of the moon, or the moon’s eastern hemisphere.
RACHEL
At the third quarter moon, the sun illuminates the moon’s western hemisphere. Unlike the first quarter moon, the third quarter moon doesn’t rise until around midnight.
PAUL
The first and third quarter moons are excellent astronomical objects for binoculars and small telescopes.
RACHEL
That’s because the terminator of the first and third quarter moons point directly towards Earth.
PAUL
As a result, the shadows on the face of the moon are stretched their longest from our perspective.
RACHEL
One thing you will notice about the third quarter moon is that the western hemisphere of the moon is covered in more extensive maria than the eastern hemisphere.
PAUL
The maria are vast lava flows that filled ancient impact basins.
RACHEL
This occurred around 3.9 billion years ago when the moon’s interior was still hot.
PAUL
The flooding occurred in waves so each eruption left a thin layer of lava covering the previous eruption.
RACHEL
When you look at the lunar maria though your binoculars, you’ll see layers of rock older than any rocks on Earth.
PAUL
The moon’s largest impact basin is 1,500 miles across and eight miles deep in places. That’s large enough to span one quarter of the moon.
RACHEL
The impact basin is located between the crater Aitken and the moon’s South Pole.
PAUL
Astronomers named this impact basin the South Pole-Aitken basin and it’s the moon’s oldest recognized impact basin.
RACHEL
Because the impact basin is located at the Moon’s South Pole, we were unaware of its existence until spacecraft began exploring the moon in the early 1960s.
PAUL
It wasn’t until the 1990s that scientists mapped the complete topography of the South Pole-Aitken basin, and discovered that it is one of the solar system’s largest impact basins.
RACHEL
May 3rd is Space Day.
PAUL
Space Day is a celebration of humanity’s exploration of outer space. It is sponsored by the aerospace company Lockheed Martin.
RACHEL
Check out the Space Day website to see if anything is happening near you. www.spaceday.org
PAUL
That’s Idaho Skies for the first week of May. Join us next week to hear about Idaho’s next meteor shower.
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.
Mizar and Alcor
This month look for the stars, Mizar and Alcor. Mizar is the star that forms the bend in the handle of the Big Dipper. Look carefully at this star and you’ll probably notice that it has a fainter companion star very close to it. The name of the companion star is Alcor and it is located at an angle directed away from the direction handle bend. Use a pair of binoculars if you’re not certain that you can see the fainter Alcor. To me, the distance between the two stars is close to the angle that 1/8th of an inch spans when viewed at arm’s distance. It may be hard to believe, but that gives Mizar and Alcor an angular separation close to ½ the diameter of the moon. When you look at Mizar with even slight optical aid, get ready for another surprise; Mizar is a double star. In 1650, Mizar was the first double star that astronomers discovered.
Mizar is over twice as massive as our sun and Alcor is over 50% heavier than our sun. The pair is located between 78 and 81 light years from the earth (the distance is uncertain). Therefore, if you were born between 1935 and 1932, Mizar and Alcor are your birthday stars this year. The actual distance between Mizar and Alcor may be anywhere between ¼ to over three light years. Therefore, it’s possible that these two stars are not actually in orbit around each other. However, if they are in orbit around each other, then their orbital period may be in the hundreds of thousands of years.
What we call The Big Dipper is not a true constellation; it is a part of the constellation of Ursa Major or the Big Bear. The constellation of the Big Bear passes high over the north during May evenings. This means that during April evenings, the Dipper is upside down and pouring its contents on the Earth below.
Sunday, April 21, 2013
Transcript of the Fourth Week of April
RACHEL
Welcome to Idaho Skies for the last week of April. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
Spica, the brightest star in Virgo, is two degrees above the moon on the evening of the 24th.
PAUL
For a sense of perspective, two degrees is approximately the width of your thumb when you fully extend your arm.
RACHEL
Spica will appear so close to the moon that you can see both together in your binoculars.
PAUL
Speaking of the moon, the moon is full on the 25th.
RACHEL
The full moon in April is often called the Egg Moon.
PAUL
When the moon is full, you’ll notice that the moon’s light renders the fainter stars invisible. In hazy or humid air, the full moon can turn the night sky a shade of light blue.
RACHEL
Although the full moon appears bright, it only reflects 12% of the sunlight shining on it.
PAUL
Astronomers use the term albedeo to describe the reflectivity of astronomical objects.
RACHEL
Albedo is a number between 0 and 1. An albedo of zero is not reflective at all and an albedo of 1 is 100% reflective.
PAUL
The moon’s albedo is about 0.12 or equal to the albedo of old asphalt.
RACHEL
Earth’s albedo on the other hand is 0.37, which means our planet reflects 37% of the sunlight shining on it.
PAUL
Can you locate Saturn in the night sky?
RACHEL
Saturn is right above the full moon on the 25th.
PAUL
Saturn will appear as a pale yellow-white star.
RACHEL
Unlike most stars however, Saturn will not twinkle.
PAUL
You need a telescope in order to see the planet’s rings; binoculars are not powerful enough.
RACHEL
Saturn and the moon rise by nine PM. So wait until at least 9:30 to look for Saturn.
PAUL
Three nights later Saturn reaches opposition.
RACHEL
That means on the 28th, Saturn is located directly opposite the sun in our sky.
PAUL
This also means that Saturn is closest to Earth.
RACHEL
At a distance of 860 million miles, the light you see from Saturn spent an hour and 17 minutes traversing the vacuum of outer space to reach your eye.
PAUL
A car driving at 70 miles per hour would need 1,400 years to reach Saturn at opposition.
RACHEL
That’s Idaho Skies for the last week of April. Listen next month for the astronomical events occurring 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.
Welcome to Idaho Skies for the last week of April. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
Spica, the brightest star in Virgo, is two degrees above the moon on the evening of the 24th.
PAUL
For a sense of perspective, two degrees is approximately the width of your thumb when you fully extend your arm.
RACHEL
Spica will appear so close to the moon that you can see both together in your binoculars.
PAUL
Speaking of the moon, the moon is full on the 25th.
RACHEL
The full moon in April is often called the Egg Moon.
PAUL
When the moon is full, you’ll notice that the moon’s light renders the fainter stars invisible. In hazy or humid air, the full moon can turn the night sky a shade of light blue.
RACHEL
Although the full moon appears bright, it only reflects 12% of the sunlight shining on it.
PAUL
Astronomers use the term albedeo to describe the reflectivity of astronomical objects.
RACHEL
Albedo is a number between 0 and 1. An albedo of zero is not reflective at all and an albedo of 1 is 100% reflective.
PAUL
The moon’s albedo is about 0.12 or equal to the albedo of old asphalt.
RACHEL
Earth’s albedo on the other hand is 0.37, which means our planet reflects 37% of the sunlight shining on it.
PAUL
Can you locate Saturn in the night sky?
RACHEL
Saturn is right above the full moon on the 25th.
PAUL
Saturn will appear as a pale yellow-white star.
RACHEL
Unlike most stars however, Saturn will not twinkle.
PAUL
You need a telescope in order to see the planet’s rings; binoculars are not powerful enough.
RACHEL
Saturn and the moon rise by nine PM. So wait until at least 9:30 to look for Saturn.
PAUL
Three nights later Saturn reaches opposition.
RACHEL
That means on the 28th, Saturn is located directly opposite the sun in our sky.
PAUL
This also means that Saturn is closest to Earth.
RACHEL
At a distance of 860 million miles, the light you see from Saturn spent an hour and 17 minutes traversing the vacuum of outer space to reach your eye.
PAUL
A car driving at 70 miles per hour would need 1,400 years to reach Saturn at opposition.
RACHEL
That’s Idaho Skies for the last week of April. Listen next month for the astronomical events occurring 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.
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