PAUL
Welcome to Idaho Skies for April 5th, 6th, and 7th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The United States and Soviet Union began sending spacecraft to Venus in the early 1960s.
RACHEL
The first spacecraft to reach Venus was the American Mariner 2. Back on December 14th, 1962, the spacecraft passed 22,000 miles away from the planet. During its flyby, Mariner 2’s microwave radiometer determined that the planet had a surface temperature of 900 degrees. This was strong confirmation of radio telescope measurements made from Earth years earlier.
PAUL
It was another five years before the next successful space mission reached Venus. In this case, it was Venera 4 launched by the Soviet Union. On October 18th, 1967, the Venera 4 capsule entered the atmosphere of Venus. This was the first time that humans ever sampled the atmosphere of another planet. Venera 4 discovered that the atmosphere of Venus consisted of around 93% carbon dioxide and 7% nitrogen.
RACHEL
Over the next five years, an additional four spacecraft reached Venus. The American spacecraft flew past Venus while the Soviet spacecraft continued making landings. On March 27th, 1972, Venera 8 was able to transmit data for 11 seconds after landing. Its measurements further confirmed that the atmosphere had both high temperature and high pressure. In fact, conditions were so extreme that they destroyed poor Venera 8.
PAUL
Venera 9 was the first lander to observe the surface of Venus on October 22nd, 1975. To survive long enough, the landing probe was pre-chilled and then placed on a trajectory that got it to the surface as quickly as possible. These precautions let Venera 9 transmit images and data for 55 minutes before succumbing to the planet’s surface temperature and pressure. The images showed a flat surface covered with loose rocks.
RACHEL
That’s Idaho Skies for the 5th, 6th, and 7th of April.
PAUL
Be sure to follow us on Twitter @IdahoSkies 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, March 31, 2019
Idaho Skies Transcript for April 3rd and 4th
RACHEL
Welcome to Idaho Skies for April 3rd and 4th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Don’t miss the Morning Star this week.
PAUL
Venus is that bright star that stargazers notice in the low east-southeast before sunrise. In fact, 6:00 AM is a good time to observe it. Due to Earth’s movement around the sun, Venus will remain visible during the mornings until July. Its position will change, but primarily along the horizon and not vertically. So compare its position to features on the horizon if you want to notice the planet’s motion.
RACHEL
Until the mid-20th century, Venus was a big unknown. Astronomers could see that the clouds covered the planet, and it had a diameter slightly smaller than Earth’s. Astronomers wondered what was under the clouds, however. No astronomer could ever see an opening though them, so the planet’s surface conditions remained a mystery.
PAUL
Radio telescopes made the first important discovery about Venus. Radio telescopes pointed at the planet discovered that it emitted radiation in the microwave range. This was useful data because all objects emit radiation based on their temperature. Astronomers knew that the hotter an object, the higher the frequency of its peak radiation emission.
RACHEL
What did this detection of microwave radiation indicate? Astronomers determined that the surface of Venus must have a temperature of around 600 degrees Fahrenheit. Carl Sagan used this result to argue that Venus had to have a high pressure atmosphere rich in carbon dioxide. In other words, Venus was suffering from a severe case of greenhouse gas.
PAUL
That’s Idaho Skies for the 3rd and 4th of April.
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 April 3rd and 4th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Don’t miss the Morning Star this week.
PAUL
Venus is that bright star that stargazers notice in the low east-southeast before sunrise. In fact, 6:00 AM is a good time to observe it. Due to Earth’s movement around the sun, Venus will remain visible during the mornings until July. Its position will change, but primarily along the horizon and not vertically. So compare its position to features on the horizon if you want to notice the planet’s motion.
RACHEL
Until the mid-20th century, Venus was a big unknown. Astronomers could see that the clouds covered the planet, and it had a diameter slightly smaller than Earth’s. Astronomers wondered what was under the clouds, however. No astronomer could ever see an opening though them, so the planet’s surface conditions remained a mystery.
PAUL
Radio telescopes made the first important discovery about Venus. Radio telescopes pointed at the planet discovered that it emitted radiation in the microwave range. This was useful data because all objects emit radiation based on their temperature. Astronomers knew that the hotter an object, the higher the frequency of its peak radiation emission.
RACHEL
What did this detection of microwave radiation indicate? Astronomers determined that the surface of Venus must have a temperature of around 600 degrees Fahrenheit. Carl Sagan used this result to argue that Venus had to have a high pressure atmosphere rich in carbon dioxide. In other words, Venus was suffering from a severe case of greenhouse gas.
PAUL
That’s Idaho Skies for the 3rd and 4th of April.
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 April 1st and 2nd
PAUL
Welcome to Idaho Skies for April 1st and 2nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Hey early-risers, look for the Morning Star this week.
RACHEL
On the morning of the 1st, Venus appears to the left of the very thin crescent moon. On the morning of the 2nd, Venus will appear on the other side of an even thinner moon. However, the moon will be so thin that you might not see it in morning twilight at 6:00 AM. You might try using your binoculars, but not if the sun has already risen.
PAUL
Venus is the very bright star in the low east-southeast. It appears so bright for two reasons. First, Venus is very close to the sun. At an average distance of 67 million miles, Venus is only 2/3rds of Earth’s distance from the sun. This means that sunlight is 225% more intense at Venus than it is at Earth. That more intense sunlight makes Venus appear as the brightest star in the sky.
RACHEL
The second reason that Venus appears so bright is that its clouds reflect more of the sunlight shining on them. Earth reflects 30% of the sunlight shining on it while Venus reflects 75%. Since the
diameters of Venus and Earth are nearly identical, size is not a factor in either planet’s brightness. Combining these two factors, distance and reflectivity makes Venus 5.5 times brighter than Earth.
PAUL
Those bright clouds are hiding a secret. Beneath them, the atmosphere of Venus reaches temperatures of 900 degrees Fahrenheit and air pressures 90 times greater than our own. This hot and dense atmosphere is also laden with sulfuric acid. With all these nasty conditions, sunlight still manages to reach the surface of Venus. Automated Russian landers have discovered that its surface is as brightly illuminated as Earth during a thunderstorm.
RACHEL
That’s Idaho Skies for the 1st and 2nd of April.
PAUL
Be sure to follow us on Twitter @IdahoSkies 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 April 1st and 2nd. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Hey early-risers, look for the Morning Star this week.
RACHEL
On the morning of the 1st, Venus appears to the left of the very thin crescent moon. On the morning of the 2nd, Venus will appear on the other side of an even thinner moon. However, the moon will be so thin that you might not see it in morning twilight at 6:00 AM. You might try using your binoculars, but not if the sun has already risen.
PAUL
Venus is the very bright star in the low east-southeast. It appears so bright for two reasons. First, Venus is very close to the sun. At an average distance of 67 million miles, Venus is only 2/3rds of Earth’s distance from the sun. This means that sunlight is 225% more intense at Venus than it is at Earth. That more intense sunlight makes Venus appear as the brightest star in the sky.
RACHEL
The second reason that Venus appears so bright is that its clouds reflect more of the sunlight shining on them. Earth reflects 30% of the sunlight shining on it while Venus reflects 75%. Since the
diameters of Venus and Earth are nearly identical, size is not a factor in either planet’s brightness. Combining these two factors, distance and reflectivity makes Venus 5.5 times brighter than Earth.
PAUL
Those bright clouds are hiding a secret. Beneath them, the atmosphere of Venus reaches temperatures of 900 degrees Fahrenheit and air pressures 90 times greater than our own. This hot and dense atmosphere is also laden with sulfuric acid. With all these nasty conditions, sunlight still manages to reach the surface of Venus. Automated Russian landers have discovered that its surface is as brightly illuminated as Earth during a thunderstorm.
RACHEL
That’s Idaho Skies for the 1st and 2nd of April.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Friday, March 15, 2019
Idaho Skies Transcript for March 22nd, 23rd, and 24th
PAUL
Welcome to Idaho Skies for March 22nd, 23rd, and 24th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Astronomer Joseph Taylor celebrates his 78th birthday on the 24th.
RACHEL
Taylor, along with astronomer Russel Hulse won a Nobel Prize in 1993. The prize was for the discovery of the first binary pulsar. Pulsars are the remains of dead stars and binary means that two dead stars are orbiting each other. Pulsars are made of neutrons and are the result of massive stars collapsing at the end of their life.
PAUL
Pulsars crush all their protons and electrons into neutrons. So they’re much smaller than the original star. Since atoms are mostly empty space, stars shrink from 100’s of thousands of miles across to only 20 miles across when they become neutron stars. That immense shrinkage means neutron stars have tremendous gravities.
RACHEL
With their small sizes also comes a high spin rate. While an adult star like the sun rotates once a month, pulsars will rotate in just seconds to minutes. Their high density and high rotation rates makes neutron stars very accurate clocks. And this what made Taylor and Hulse’s binary pulsar discovery so important.
PAUL
They determined that the orbital period, or year, of the binary pulsar was slowly decreasing. Now why should the pulsars’ year decreasing? Because the binary pair was losing orbital energy to their immense gravitational field. And this became the first, indirect discovery of gravity waves.
RACHEL
That’s Idaho Skies for the 22nd, 23rd, and 24th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for March 22nd, 23rd, and 24th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Astronomer Joseph Taylor celebrates his 78th birthday on the 24th.
RACHEL
Taylor, along with astronomer Russel Hulse won a Nobel Prize in 1993. The prize was for the discovery of the first binary pulsar. Pulsars are the remains of dead stars and binary means that two dead stars are orbiting each other. Pulsars are made of neutrons and are the result of massive stars collapsing at the end of their life.
PAUL
Pulsars crush all their protons and electrons into neutrons. So they’re much smaller than the original star. Since atoms are mostly empty space, stars shrink from 100’s of thousands of miles across to only 20 miles across when they become neutron stars. That immense shrinkage means neutron stars have tremendous gravities.
RACHEL
With their small sizes also comes a high spin rate. While an adult star like the sun rotates once a month, pulsars will rotate in just seconds to minutes. Their high density and high rotation rates makes neutron stars very accurate clocks. And this what made Taylor and Hulse’s binary pulsar discovery so important.
PAUL
They determined that the orbital period, or year, of the binary pulsar was slowly decreasing. Now why should the pulsars’ year decreasing? Because the binary pair was losing orbital energy to their immense gravitational field. And this became the first, indirect discovery of gravity waves.
RACHEL
That’s Idaho Skies for the 22nd, 23rd, and 24th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
RACHEL
Dark skies and bright stars.
Idaho Skies Transcript for March 20th and 21st
RACHEL
Welcome to Idaho Skies for March 20th and 21st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Spring begins on the 20th. Yippee!!
PAUL
Spring is called the Vernal Equinox - vernal for spring and equinox for equal night. On the Vernal Equinox, Earth’s spin axis aligns vertically with its orbital plane around the sun. As a result, the boundary between day and night, or its terminator runs from pole to pole. No matter where you live on Earth, the day and night will both be 12 hours long.
RACHEL
On the 21st, the moon is full. If you want to be blinded by the light, then look at the moon through your binoculars. This is safe, but it will leave an after-image in your eyes that takes several minutes to clear. The thing about the full moon is that you don’t see shadows of craters on its surface; you’ll instead see how bright and dark its surface is.
PAUL
Stargazers will notice that the full moon appears between bright stars on the 21st. One star is closer to the moon at its lower right. The other star is farther away and to the moon’s upper left. Stargazers will also notice the stars have distinctly different tints. The lower star is a white spark of light while the upper star has more of a ruddy glow.
RACHEL
The lower star is named Spica and it’s the brightest star of Virgo the Maiden. The upper star is named Arcturus and it’s the brightest star of Bootes the Herdsman. One way to find these stars when the moon isn’t nearby is to follow the handle of the dipper. A line extending from the Dipper’s handle arcs to Arcturus and drives a spike to Spica.
PAUL
That’s Idaho Skies for the 20th and 21st of March.
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 March 20th and 21st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Spring begins on the 20th. Yippee!!
PAUL
Spring is called the Vernal Equinox - vernal for spring and equinox for equal night. On the Vernal Equinox, Earth’s spin axis aligns vertically with its orbital plane around the sun. As a result, the boundary between day and night, or its terminator runs from pole to pole. No matter where you live on Earth, the day and night will both be 12 hours long.
RACHEL
On the 21st, the moon is full. If you want to be blinded by the light, then look at the moon through your binoculars. This is safe, but it will leave an after-image in your eyes that takes several minutes to clear. The thing about the full moon is that you don’t see shadows of craters on its surface; you’ll instead see how bright and dark its surface is.
PAUL
Stargazers will notice that the full moon appears between bright stars on the 21st. One star is closer to the moon at its lower right. The other star is farther away and to the moon’s upper left. Stargazers will also notice the stars have distinctly different tints. The lower star is a white spark of light while the upper star has more of a ruddy glow.
RACHEL
The lower star is named Spica and it’s the brightest star of Virgo the Maiden. The upper star is named Arcturus and it’s the brightest star of Bootes the Herdsman. One way to find these stars when the moon isn’t nearby is to follow the handle of the dipper. A line extending from the Dipper’s handle arcs to Arcturus and drives a spike to Spica.
PAUL
That’s Idaho Skies for the 20th and 21st of March.
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 March 18th and 19th
PAUL
Welcome to Idaho Skies for March 18th and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
A bright yellowish star appears next to the moon on the 18th.
RACHEL
The star’s name is Regulus and its only three degrees away from the moon. Three degrees of separation means that you can see both together through binoculars. Regulus is the brightest star of Leo the Lion. Leo the Lion is one of the signs of the zodiac. Did you know that there aren’t 12 constellations in the zodiac?
PAUL
First off, we should explain that the zodiac is a series of constellations that the sun, moon, and planets travel though. Now there are twelve signs of the traditional zodiac, but the sun travels through 13 constellations over the course of a year. So why this mismatch? Well, in a word it’s because of precession.
RACHEL
Precession results from a wobble in Earth’s spin axis. Earth spins on its axis once every 24 hours to create day and night. However, the spin axis itself spins in a larger circle over 26,000 years. So when the zodiac was designed 2,000 years ago, the sun did indeed pass through 12 constellations according to the ancients.
PAUL
Earth’s spin axis has wobbled through 7% of its path in the last 2,000 years. Because of this and the new boundaries for the constellations that astronomers created last century, the zodiac includes a new constellation, Ophiuchus. Ophiuchus is the Serpent Bearer and it’s above Scorpius the Scorpion. I wonder how many of our listeners are Ophiuchians?
RACHEL
That’s Idaho Skies for the 18th and 19th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies 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 March 18th and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
A bright yellowish star appears next to the moon on the 18th.
RACHEL
The star’s name is Regulus and its only three degrees away from the moon. Three degrees of separation means that you can see both together through binoculars. Regulus is the brightest star of Leo the Lion. Leo the Lion is one of the signs of the zodiac. Did you know that there aren’t 12 constellations in the zodiac?
PAUL
First off, we should explain that the zodiac is a series of constellations that the sun, moon, and planets travel though. Now there are twelve signs of the traditional zodiac, but the sun travels through 13 constellations over the course of a year. So why this mismatch? Well, in a word it’s because of precession.
RACHEL
Precession results from a wobble in Earth’s spin axis. Earth spins on its axis once every 24 hours to create day and night. However, the spin axis itself spins in a larger circle over 26,000 years. So when the zodiac was designed 2,000 years ago, the sun did indeed pass through 12 constellations according to the ancients.
PAUL
Earth’s spin axis has wobbled through 7% of its path in the last 2,000 years. Because of this and the new boundaries for the constellations that astronomers created last century, the zodiac includes a new constellation, Ophiuchus. Ophiuchus is the Serpent Bearer and it’s above Scorpius the Scorpion. I wonder how many of our listeners are Ophiuchians?
RACHEL
That’s Idaho Skies for the 18th and 19th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Monday, March 11, 2019
Idaho Skies Transcript for March 15th, 16th, and 17th
RACHEL
Welcome to Idaho Skies for March 15th, 16th, and 17th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The Beehive star cluster will be an easy target this weekend.
PAUL
The Beehive is one of the largest and brightest star clusters. In fact, it can be seen outside of town under dark skies. It appears as a hazy spot in the center of Cancer the Crab. Of course, it doesn’t help that Cancer is such a small and faint constellation. So it’s easier to find the Beehive star cluster than the rest of Cancer the Crab.
RACHEL
Before the invention of the telescope, people recorded the Beehive as a nebulous patch in the sky. It was pictured as a manager or crib where two donkeys were feeding. Those donkeys are the two central stars of Cancer. It wasn’t until 1609 when Galileo turned his newly invented telescope to the Beehive that we understood its true nature.
PAUL
Through his little telescope, Galileo counted 40 stars residing inside this fuzzy spot. Today astronomers know there are over one thousand stars inside the cluster. The apparent diameter of the cluster is 1.5 degrees, or three times larger than the moon. But you won’t believe this until you see them next to each other.
RACHEL
And that’s what happens on Saturday night. Aim your binoculars at the moon after its gets dark, like at 9:00 PM. Then place the moon just above the 3 o’clock position of your view. The Beehive will appear on the other side of the binoculars just below the 9 o’clock position. Now does the Beehive look larger than the moon?
PAUL
That’s Idaho Skies for the 15th, 16th, and 17th of March.
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 March 15th, 16th, and 17th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The Beehive star cluster will be an easy target this weekend.
PAUL
The Beehive is one of the largest and brightest star clusters. In fact, it can be seen outside of town under dark skies. It appears as a hazy spot in the center of Cancer the Crab. Of course, it doesn’t help that Cancer is such a small and faint constellation. So it’s easier to find the Beehive star cluster than the rest of Cancer the Crab.
RACHEL
Before the invention of the telescope, people recorded the Beehive as a nebulous patch in the sky. It was pictured as a manager or crib where two donkeys were feeding. Those donkeys are the two central stars of Cancer. It wasn’t until 1609 when Galileo turned his newly invented telescope to the Beehive that we understood its true nature.
PAUL
Through his little telescope, Galileo counted 40 stars residing inside this fuzzy spot. Today astronomers know there are over one thousand stars inside the cluster. The apparent diameter of the cluster is 1.5 degrees, or three times larger than the moon. But you won’t believe this until you see them next to each other.
RACHEL
And that’s what happens on Saturday night. Aim your binoculars at the moon after its gets dark, like at 9:00 PM. Then place the moon just above the 3 o’clock position of your view. The Beehive will appear on the other side of the binoculars just below the 9 o’clock position. Now does the Beehive look larger than the moon?
PAUL
That’s Idaho Skies for the 15th, 16th, and 17th of March.
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 March 13th and 14th
PAUL
Welcome to Idaho Skies for March 13th and 14th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The first quarter moon passes very close to the M-35 star cluster on the 14th.
RACHEL
This means stargazers will have two excellent binocular targets on Thursday night. The moon shows its best detail when it’s at the first quarter phase. Best of all, many of these details are visible through modest binoculars. For example, stargazers will see that the moon’s southern hemisphere is packed with craters.
PAUL
It’s packed because the lunar southern highlands are old. This part of the lunar surface dates back to a time when the inner solar system was dense with orbiting planetesimals. These planetesimals were the building blocks of planets 4.5 billion years ago. And after the planets finally solidified from the solar nebula, there were still plenty of planetesimals left over.
RACHEL
It may have been the shifting positions of Jupiter and Saturn that sent many of these remaining planetesimals careening inward. Their impacts left scars on all the inner planets, none escaped this heavenly rain. However, Venus and Earth have erased all of those impact scars through weathering. Mars still has some, but Mercury and the moon still maintain their scars.
PAUL
Stargazers viewing the impact scars from what astronomers call the late heavy bombardment should also look for star cluster M-35 on the 14th. The star cluster is 3.5 degrees above the moon. To find it, place the moon at the bottom of your binoculars’ view. The star cluster will then be straight up and in the center of your view.
RACHEL
That’s Idaho Skies for the 13th and 14th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies 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 March 13th and 14th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The first quarter moon passes very close to the M-35 star cluster on the 14th.
RACHEL
This means stargazers will have two excellent binocular targets on Thursday night. The moon shows its best detail when it’s at the first quarter phase. Best of all, many of these details are visible through modest binoculars. For example, stargazers will see that the moon’s southern hemisphere is packed with craters.
PAUL
It’s packed because the lunar southern highlands are old. This part of the lunar surface dates back to a time when the inner solar system was dense with orbiting planetesimals. These planetesimals were the building blocks of planets 4.5 billion years ago. And after the planets finally solidified from the solar nebula, there were still plenty of planetesimals left over.
RACHEL
It may have been the shifting positions of Jupiter and Saturn that sent many of these remaining planetesimals careening inward. Their impacts left scars on all the inner planets, none escaped this heavenly rain. However, Venus and Earth have erased all of those impact scars through weathering. Mars still has some, but Mercury and the moon still maintain their scars.
PAUL
Stargazers viewing the impact scars from what astronomers call the late heavy bombardment should also look for star cluster M-35 on the 14th. The star cluster is 3.5 degrees above the moon. To find it, place the moon at the bottom of your binoculars’ view. The star cluster will then be straight up and in the center of your view.
RACHEL
That’s Idaho Skies for the 13th and 14th of March.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul…
RACHEL
…and Rachel.
PAUL
Dark skies and bright stars.
Idaho Skies Transcript for March 11th and 12th
RACHEL
Welcome to Idaho Skies for March 11th and 12th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is passing through two star clusters at the beginning of this week.
PAUL
The star clusters are the Pleiades and the Hyades. Both are perfect for your binoculars. In fact, most telescopes will magnify them too much. That is, except for rich field telescopes. These telescopes have very short focal lengths in comparison to their diameters. Astronomers and camera enthusiasts call this the f-number and the lower the f-number, the wider the telescope’s field of view.
RACHEL
Since most binoculars have an f-number of around four, they have very wide fields of view. Common binoculars have fields of five or six degrees, which is between ten and twelve times wider than the moon’s apparent diameter. The Hyades and Pleiades star clusters have diameters of five and two degrees respectively. It’s no wonder binoculars are perfect for observing them.
PAUL
Under dark skies, you should be able to see over a dozen stars in each star cluster. Even in town, the star clusters will be very attractive in your binoculars. However, it’s best if you could get out from underneath a street light and away from your porch lights. Your view is better if you can prop up your binoculars.
RACHEL
Without propping binoculars, your hands shake them. So fewer photons of light reach the rod and cone cells in your retina. With fewer photons, retinal cells are less likely to register faint stars. So try propping your arms or elbows on a solid surface, like a car or a wall. Then watch as the moon passes through the Hyades star cluster on the 12th.
PAUL
That’s Idaho Skies for the 11th and 12th of March.
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 March 11th and 12th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon is passing through two star clusters at the beginning of this week.
PAUL
The star clusters are the Pleiades and the Hyades. Both are perfect for your binoculars. In fact, most telescopes will magnify them too much. That is, except for rich field telescopes. These telescopes have very short focal lengths in comparison to their diameters. Astronomers and camera enthusiasts call this the f-number and the lower the f-number, the wider the telescope’s field of view.
RACHEL
Since most binoculars have an f-number of around four, they have very wide fields of view. Common binoculars have fields of five or six degrees, which is between ten and twelve times wider than the moon’s apparent diameter. The Hyades and Pleiades star clusters have diameters of five and two degrees respectively. It’s no wonder binoculars are perfect for observing them.
PAUL
Under dark skies, you should be able to see over a dozen stars in each star cluster. Even in town, the star clusters will be very attractive in your binoculars. However, it’s best if you could get out from underneath a street light and away from your porch lights. Your view is better if you can prop up your binoculars.
RACHEL
Without propping binoculars, your hands shake them. So fewer photons of light reach the rod and cone cells in your retina. With fewer photons, retinal cells are less likely to register faint stars. So try propping your arms or elbows on a solid surface, like a car or a wall. Then watch as the moon passes through the Hyades star cluster on the 12th.
PAUL
That’s Idaho Skies for the 11th and 12th of March.
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.
Subscribe to:
Posts (Atom)