RACHEL
Welcome to Idaho Skies for March 1st, 2nd, and 3rd. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Stargazers will see the moon slide past two planets on Friday and Saturday morning.
PAUL
On Friday morning, look in the low southeast for the waning crescent moon. You might see Earthshine along with a star to the moon’s left. That star is Saturn, the ringed wonder of our solar system. Sadly, a pair of binoculars will not show you the planet’s rings or its largest satellite. However, a small telescope or even a spotting scope is capable of showing you these things. That is, if the telescope can magnify at least 25 times.
RACHEL
Through an astronomical telescope, which inverts images, Saturn’s rings will be tilted from the lower left to upper right. Titan, the second largest moon in the solar system, will appear to Saturn’s upper left. A non-inverting spotting scope still shows Saturn’s rings tilted from lower left to upper right. However, Titan will appear to Saturn’s lower right instead.
PAUL
On Saturday morning, the even thinner crescent moon appears to the right of the bright Morning Star. Venus is on its way back to the sun. Because of the relative motion between Venus and Earth, the Morning Star takes its time this year approaching the horizon. This means stargazers will have until the Fourth of July to observe Venus as the Morning Star.
RACHEL
Venus is a rocky world like Earth. It even has an atmosphere, but one unlike our own. Its air pressure of 90 times greater than Earth’s is similar to the water pressure found 3,000 feet deep in the ocean. Its atmospheric temperature is 900 degrees. That’s far hotter than any kitchen oven. These conditions exist on Venus probably because it lost its supply of water long ago.
PAUL
That’s Idaho Skies for the 1st, 2nd, and 3rd 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.
Monday, February 25, 2019
Idaho Skies Transcript for February 27th and 28th
PAUL
Welcome to Idaho Skies for February 27th and 28th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
What’s the star below the moon on the morning of the 27th?
RACHEL
Early-risers Wednesday morning will see a bright star one and a half degrees beneath the moon. Since this star won’t twinkle, you can be certain that it will be a planet and not a real star. And since it will be bright and slightly mellow-white in color, it must be Jupiter. But just to be sure, aim your binoculars or small telescope at it.
PAUL
Your binoculars will show you at least one Jovian satellite and possibly two others close to the planet. However, if you use a telescope you’ll see all four of Jupiter’s major satellites. From left to right in a telescope that doesn’t invert images; you’ll see Europa, Io really close to Jupiter, Jupiter itself, Ganymede, and finally Callisto. Binoculars will let you at least see Callisto on the far right.
RACHEL
Stargazers looking at the western horizon shortly after sunset will see a different planet on the 28th. This planet is Mercury, our solar system’s innermost planet. Mercury will appear fainter than Jupiter and purer white in color. This planet never appears very far away from the sun, so stargazers will only have a few days to see it.
PAUL
Mercury and Jupiter are dramatically different worlds. Mercury is rocky like Earth and less than half its diameter. Jupiter is mostly gas and 11 times larger than the earth. Since Mercury is rocky, its surface is scarred with craters. Jupiter, on the other hand swallows up meteors. Only the largest impacts leave their mark on Jupiter. But these dark stains in its atmosphere usually disappear in days to weeks.
RACHEL
That’s Idaho Skies for the 27th and 28th of February.
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 February 27th and 28th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
What’s the star below the moon on the morning of the 27th?
RACHEL
Early-risers Wednesday morning will see a bright star one and a half degrees beneath the moon. Since this star won’t twinkle, you can be certain that it will be a planet and not a real star. And since it will be bright and slightly mellow-white in color, it must be Jupiter. But just to be sure, aim your binoculars or small telescope at it.
PAUL
Your binoculars will show you at least one Jovian satellite and possibly two others close to the planet. However, if you use a telescope you’ll see all four of Jupiter’s major satellites. From left to right in a telescope that doesn’t invert images; you’ll see Europa, Io really close to Jupiter, Jupiter itself, Ganymede, and finally Callisto. Binoculars will let you at least see Callisto on the far right.
RACHEL
Stargazers looking at the western horizon shortly after sunset will see a different planet on the 28th. This planet is Mercury, our solar system’s innermost planet. Mercury will appear fainter than Jupiter and purer white in color. This planet never appears very far away from the sun, so stargazers will only have a few days to see it.
PAUL
Mercury and Jupiter are dramatically different worlds. Mercury is rocky like Earth and less than half its diameter. Jupiter is mostly gas and 11 times larger than the earth. Since Mercury is rocky, its surface is scarred with craters. Jupiter, on the other hand swallows up meteors. Only the largest impacts leave their mark on Jupiter. But these dark stains in its atmosphere usually disappear in days to weeks.
RACHEL
That’s Idaho Skies for the 27th and 28th of February.
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 February 25th and 26th
RACHEL
Welcome to Idaho Skies for February 25th and 26th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon is at third quarter on the morning of the 26th.
PAUL
Third quarter means the western hemisphere of the moon is visible. From our perspective, that’s the right side of the moon. Since the moon is at third quarter, it rises around midnight and sets around noon. Like the first quarter moon, the third quarter moon is an excellent target for binoculars or small telescope.
RACHEL
When you look at the third quarter moon with optical aid, be sure to look for a round lunar sea at the top right of the moon. This mare is very round and ringed with mountain ranges. It goes by the name of the Sea of Rains and its 711 miles across. That means you could place over four copies of Idaho comfortably into this sea and still have room to spare.
PAUL
The Sea of Rains has several features you’ll enjoy observing. First of all are the mountain ranges you’ll see ringing most of the mare. At its lower left is the Apennine mountain range. This curved mountain chain is 370 miles long and has peaks reaching 16,000 feet tall. Apollo 15 landed near the northern end of this mountain range.
RACHEL
To the upper right of the Sea of Rains is a less dramatic mountain range, the Alps. Don’t confuse the Alps for the Caucasus Mountains. The Alps curl over the top of the Sea of Rains while the Caucasus Mountains are more vertical. Finally, look for Plato, the large dark crater just underneath the Alps.
PAUL
That’s Idaho Skies for the 25th and 26th of February.
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 February 25th and 26th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon is at third quarter on the morning of the 26th.
PAUL
Third quarter means the western hemisphere of the moon is visible. From our perspective, that’s the right side of the moon. Since the moon is at third quarter, it rises around midnight and sets around noon. Like the first quarter moon, the third quarter moon is an excellent target for binoculars or small telescope.
RACHEL
When you look at the third quarter moon with optical aid, be sure to look for a round lunar sea at the top right of the moon. This mare is very round and ringed with mountain ranges. It goes by the name of the Sea of Rains and its 711 miles across. That means you could place over four copies of Idaho comfortably into this sea and still have room to spare.
PAUL
The Sea of Rains has several features you’ll enjoy observing. First of all are the mountain ranges you’ll see ringing most of the mare. At its lower left is the Apennine mountain range. This curved mountain chain is 370 miles long and has peaks reaching 16,000 feet tall. Apollo 15 landed near the northern end of this mountain range.
RACHEL
To the upper right of the Sea of Rains is a less dramatic mountain range, the Alps. Don’t confuse the Alps for the Caucasus Mountains. The Alps curl over the top of the Sea of Rains while the Caucasus Mountains are more vertical. Finally, look for Plato, the large dark crater just underneath the Alps.
PAUL
That’s Idaho Skies for the 25th and 26th of February.
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.
Tuesday, February 19, 2019
Idaho Skies Transcript for February 22nd, 23rd, and 24th
PAUL
Welcome to Idaho Skies for February 22nd, 23rd, and 24th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
This Sunday marks the 51st anniversary of the announcement of the pulsar in Nature, a science journal.
RACHEL
In November 1967, grad student Jocelyn Bell was monitoring the sky with a radio telescope. As radio emitting objects passes through the beam of the stationary radio telescope, their signals were recorded on a strip chart recorder. She noticed that one of the signals recorded on her instruments repeated regularly at 1.3 seconds.
PAUL
The regularity of the signal was too perfect for any astronomical object known in 1967. For a short time, she and her advising professor named the source of the signal, LGM-1. LGM by the way stood for Little Green Men. She and her professor didn’t really think the source of the radio signal was an extraterrestrial intelligence, but the signal was a little too perfect.
RACHEL
Astronomers Baade and Zwicky had predicted the existence of dead stars smaller than white dwarfs back in 1934. These dead stars would be so dense that only their neutrons could halt further gravitational collapse. Their small size, on the order of 20 miles, would also make them spin incredibly fast. And if they emitted radiation, like radio waves, they could flash on and off several times per second with fantastic precision and regularity.
PAUL
It was 33 years later when Bell discovered the first four of these spinning neutron stars. Today, astronomers have discovered some 2,000 neutron stars and the fastest rotates 716 times per second. That means at its equator, the neutron star is spinning at 44,700 miles per second. That’s 24% the speed of light. Even more strangely, there are four known pulsars with planets. How weird can neutron stars get?
RACHEL
That’s Idaho Skies for the 22nd, 23rd, and 24th of February.
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 February 22nd, 23rd, and 24th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
This Sunday marks the 51st anniversary of the announcement of the pulsar in Nature, a science journal.
RACHEL
In November 1967, grad student Jocelyn Bell was monitoring the sky with a radio telescope. As radio emitting objects passes through the beam of the stationary radio telescope, their signals were recorded on a strip chart recorder. She noticed that one of the signals recorded on her instruments repeated regularly at 1.3 seconds.
PAUL
The regularity of the signal was too perfect for any astronomical object known in 1967. For a short time, she and her advising professor named the source of the signal, LGM-1. LGM by the way stood for Little Green Men. She and her professor didn’t really think the source of the radio signal was an extraterrestrial intelligence, but the signal was a little too perfect.
RACHEL
Astronomers Baade and Zwicky had predicted the existence of dead stars smaller than white dwarfs back in 1934. These dead stars would be so dense that only their neutrons could halt further gravitational collapse. Their small size, on the order of 20 miles, would also make them spin incredibly fast. And if they emitted radiation, like radio waves, they could flash on and off several times per second with fantastic precision and regularity.
PAUL
It was 33 years later when Bell discovered the first four of these spinning neutron stars. Today, astronomers have discovered some 2,000 neutron stars and the fastest rotates 716 times per second. That means at its equator, the neutron star is spinning at 44,700 miles per second. That’s 24% the speed of light. Even more strangely, there are four known pulsars with planets. How weird can neutron stars get?
RACHEL
That’s Idaho Skies for the 22nd, 23rd, and 24th of February.
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 February 20th and 21st
RACHEL
Welcome to Idaho Skies for February 20th and 21st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
George Smoot celebrates his 74th birthday on the 20th.
PAUL
Listeners might not be familiar with the name of George Smoot. But he’s an American astrophysicist who researched the cosmic microwave background, or CMB. When the universe formed, it began expanding from an incredibly dense and hot state. There was no matter at the time, everything was energy. And that energy was too hot and intense for subatomic particles to exist.
RACHEL
As the universe expanded, it cooled to the point that subatomic particles could exist. The universe was only one millionth of a second old when subatomic particles finally became stable. However, there were no atoms as we known of them today. The universe was still too hot for protons, neutrons, and electrons to remain together. Every time a neutral atom tried to form, photons of energy knocked it apart.
PAUL
Those photons came from the background temperature of the universe. Everything with a temperature above Absolute Zero emits photons of light or radiation, and the universe is no different. It took another 380,000 years before the universe was cool enough for neutral atoms to exist. By then, the universe was a balmy 5,000 degrees.
RACHEL
The neutral atoms left their imprint in the cosmic background of the universe as tiny temperature fluctuations. Today the universe is only 5 degrees Fahrenheit above Absolute Zero, so the background radiation appears as microwaves. What Smoot found in 1992 was tiny temperature variations in this microwave background. Those slightly warmer and cooler patches in the CMB are among the strongest evidence for the Big Bang.
PAUL
That’s Idaho Skies for the 20th and 21st of February.
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 February 20th and 21st. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
George Smoot celebrates his 74th birthday on the 20th.
PAUL
Listeners might not be familiar with the name of George Smoot. But he’s an American astrophysicist who researched the cosmic microwave background, or CMB. When the universe formed, it began expanding from an incredibly dense and hot state. There was no matter at the time, everything was energy. And that energy was too hot and intense for subatomic particles to exist.
RACHEL
As the universe expanded, it cooled to the point that subatomic particles could exist. The universe was only one millionth of a second old when subatomic particles finally became stable. However, there were no atoms as we known of them today. The universe was still too hot for protons, neutrons, and electrons to remain together. Every time a neutral atom tried to form, photons of energy knocked it apart.
PAUL
Those photons came from the background temperature of the universe. Everything with a temperature above Absolute Zero emits photons of light or radiation, and the universe is no different. It took another 380,000 years before the universe was cool enough for neutral atoms to exist. By then, the universe was a balmy 5,000 degrees.
RACHEL
The neutral atoms left their imprint in the cosmic background of the universe as tiny temperature fluctuations. Today the universe is only 5 degrees Fahrenheit above Absolute Zero, so the background radiation appears as microwaves. What Smoot found in 1992 was tiny temperature variations in this microwave background. Those slightly warmer and cooler patches in the CMB are among the strongest evidence for the Big Bang.
PAUL
That’s Idaho Skies for the 20th and 21st of February.
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 February 18th and 19th
PAUL
Welcome to Idaho Skies for February 18th and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Early risers, look for a close encounter between Venus and Saturn.
RACHEL
Venus has been a morning fixture for months. Since it’s an inferior planet, it’s reaching its maximum distance above the horizon. This means its position doesn’t change very much from day to day. But Saturn is a superior planet and it’s relentlessly climbing higher every day.
PAUL
This week stargazers will see the position between Venus and Saturn change substantially every day. And on the morning of the 18th, the two planets will appear their closest together. Venus will be the brightest star in the low east-southeast and Saturn will appear slightly below it. Stargazers with binoculars will notice a third star in the region. That star is pi Sagittarii and its closer to Venus and fainter than Saturn.
RACHEL
Stargazers with a telescope can observe the rings around Saturn and the phase of Venus. Unfortunately, binoculars do not have enough magnification to do this. It takes at least a magnification of 25 power to see Saturn’s rings and it brightest satellite, Titan. The phase of Venus is easier to see when it’s closer to dawn, or when the sky is bringing to brighten.
PAUL
Stargazers who don’t have free time early in the morning should check out the moon on the evening of the 18th. The moon will appear next to Leo the Lion and its brightest star, Regulus. Regulus means Little King in Latin, an appropriate name for the brightest star in the constellation of the lion. Look for a backwards question mark of stars rising above Regulus. This represents the back of the Lion’s mane.
RACHEL
That’s Idaho Skies for the 18th and 19th of February.
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 February 18th and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Early risers, look for a close encounter between Venus and Saturn.
RACHEL
Venus has been a morning fixture for months. Since it’s an inferior planet, it’s reaching its maximum distance above the horizon. This means its position doesn’t change very much from day to day. But Saturn is a superior planet and it’s relentlessly climbing higher every day.
PAUL
This week stargazers will see the position between Venus and Saturn change substantially every day. And on the morning of the 18th, the two planets will appear their closest together. Venus will be the brightest star in the low east-southeast and Saturn will appear slightly below it. Stargazers with binoculars will notice a third star in the region. That star is pi Sagittarii and its closer to Venus and fainter than Saturn.
RACHEL
Stargazers with a telescope can observe the rings around Saturn and the phase of Venus. Unfortunately, binoculars do not have enough magnification to do this. It takes at least a magnification of 25 power to see Saturn’s rings and it brightest satellite, Titan. The phase of Venus is easier to see when it’s closer to dawn, or when the sky is bringing to brighten.
PAUL
Stargazers who don’t have free time early in the morning should check out the moon on the evening of the 18th. The moon will appear next to Leo the Lion and its brightest star, Regulus. Regulus means Little King in Latin, an appropriate name for the brightest star in the constellation of the lion. Look for a backwards question mark of stars rising above Regulus. This represents the back of the Lion’s mane.
RACHEL
That’s Idaho Skies for the 18th and 19th of February.
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, February 11, 2019
Idaho Skies Transcript for February 15th, 16th, and 17th
RACHEL
Welcome to Idaho Skies for February 15th, 16th, and 17th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon passes a large star cluster this week and many people have never seen it.
PAUL
The cluster is the Beehive star cluster. It has an apparent diameter of ½ of a degree, or as large as the moon. The cluster resides in Cancer the Crab and can be glimpsed without binoculars, if you’re in dark skies. Since the star cluster is reasonably bright, it can be seen in town, but only through your binoculars.
RACHEL
The Beehive has been known since antiquity. However, its true nature was unknown at the time. Without optical aid, the star cluster only appears as a fuzzy cloud or nebula. Galileo discovered it was actually a collection of stars in 1609. But it took the invention of the telescope for him to make this discovery.
PAUL
On Sunday night, aim your binoculars at the nearly full moon. The moon is skirting the edge of the Beehive, so this is a great opportunity to compare the apparent size of the two. The moon’s light will create enough glare that it will make it difficult to see the faintest of the stars of the cluster. When the moon is not present, you can see around two dozen stars in this cluster.
RACHEL
A star cluster is created from a molecular hydrogen cloud, or a region of gas that’s denser than the gas that normally fills the galaxy. A shock wave or a passing star can create a slightly denser region in a molecular cloud. That lets gravity overcome gas pressure and shrink the clump of gas even more. And over time, the gas clump breaks up into hundreds or even thousands of tinier clumps that continue to collapse into individual stars.
PAUL
That’s Idaho Skies for the 15th, 16th, and 17th of February.
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 February 15th, 16th, and 17th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The moon passes a large star cluster this week and many people have never seen it.
PAUL
The cluster is the Beehive star cluster. It has an apparent diameter of ½ of a degree, or as large as the moon. The cluster resides in Cancer the Crab and can be glimpsed without binoculars, if you’re in dark skies. Since the star cluster is reasonably bright, it can be seen in town, but only through your binoculars.
RACHEL
The Beehive has been known since antiquity. However, its true nature was unknown at the time. Without optical aid, the star cluster only appears as a fuzzy cloud or nebula. Galileo discovered it was actually a collection of stars in 1609. But it took the invention of the telescope for him to make this discovery.
PAUL
On Sunday night, aim your binoculars at the nearly full moon. The moon is skirting the edge of the Beehive, so this is a great opportunity to compare the apparent size of the two. The moon’s light will create enough glare that it will make it difficult to see the faintest of the stars of the cluster. When the moon is not present, you can see around two dozen stars in this cluster.
RACHEL
A star cluster is created from a molecular hydrogen cloud, or a region of gas that’s denser than the gas that normally fills the galaxy. A shock wave or a passing star can create a slightly denser region in a molecular cloud. That lets gravity overcome gas pressure and shrink the clump of gas even more. And over time, the gas clump breaks up into hundreds or even thousands of tinier clumps that continue to collapse into individual stars.
PAUL
That’s Idaho Skies for the 15th, 16th, and 17th of February.
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 February 13th and 14th
PAUL
Welcome to Idaho Skies for February 13th and 14th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon appears in Taurus the Bull and near its largest star cluster during the middle of the week.
RACHEL
The Hyades is a large star cluster. It’s not compact like the older globular clusters. Instead, it’s spread out and relatively young. Astronomers believe that the stars in this cluster are only 625 million years old. While that may seem old to us, to the sun and solar system, this is incredibly young.
PAUL
When the solar system was that young, Earth was near the end of the Hadean Eon. There are very few Earth rocks from this age for geologists to study. The available evidence however, suggests that Earth’s crust had just solidified by this time and that bodies of water existed on its surface. Earth’s atmosphere must have been much denser during this time in order to keep the oceans liquid on such a hot planet.
RACHEL
So if Earth is a typical example, any planets in the Hyades must be sterile of life. But if a planet’s atmosphere is clear, its sky would be loaded with bright stars. That’s because stars are packed about four times more densely in the Hyades than in the sun’s neighborhood. Just imagine what it would be like to stand on a planet with lots of volcanoes and geysers, while admiring its star-filled sky.
PAUL
To see the Hyades, just look to the right of the moon. The Hyades appears as a V-shape grouping of stars. The bright orange star closest to the moon is named Aldebaran, but it’s not really a member of the Hyades - it just happens to line directly between the Hyades and the solar system. Your best view of this star cluster is through a pair of binoculars. Don’t use a telescope, as it will magnify too much.
RACHEL
That’s Idaho Skies for the 13th and 14th of February.
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 February 13th and 14th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon appears in Taurus the Bull and near its largest star cluster during the middle of the week.
RACHEL
The Hyades is a large star cluster. It’s not compact like the older globular clusters. Instead, it’s spread out and relatively young. Astronomers believe that the stars in this cluster are only 625 million years old. While that may seem old to us, to the sun and solar system, this is incredibly young.
PAUL
When the solar system was that young, Earth was near the end of the Hadean Eon. There are very few Earth rocks from this age for geologists to study. The available evidence however, suggests that Earth’s crust had just solidified by this time and that bodies of water existed on its surface. Earth’s atmosphere must have been much denser during this time in order to keep the oceans liquid on such a hot planet.
RACHEL
So if Earth is a typical example, any planets in the Hyades must be sterile of life. But if a planet’s atmosphere is clear, its sky would be loaded with bright stars. That’s because stars are packed about four times more densely in the Hyades than in the sun’s neighborhood. Just imagine what it would be like to stand on a planet with lots of volcanoes and geysers, while admiring its star-filled sky.
PAUL
To see the Hyades, just look to the right of the moon. The Hyades appears as a V-shape grouping of stars. The bright orange star closest to the moon is named Aldebaran, but it’s not really a member of the Hyades - it just happens to line directly between the Hyades and the solar system. Your best view of this star cluster is through a pair of binoculars. Don’t use a telescope, as it will magnify too much.
RACHEL
That’s Idaho Skies for the 13th and 14th of February.
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 February 11th and 12th
RACHEL
Welcome to Idaho Skies for February 11th and 12th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Hey, the moon reaches first quarter phase today.
PAUL
At first quarter, only the eastern half of the moon is visible. That’s because sunlight is also illuminating half of the moon’s farside. The boundary between day and night is called the moon’s terminator. It’s where sunrise is occurring on the moon. Since the sun is just rising along the terminator, shadows are especially long there. That makes it easier to see craters and mountains that reside along the terminator.
RACHEL
The moon has a near and far side because its day lasts 29 Earth days, the same time it takes for the moon to orbit Earth. Astronomers use the term tidally locked to describe this situation. Small moons are normally tidally locked to their host planet when the moons are close to the planet. Because it’s tidally locked, the lunar farside was luna incognita until the beginning of the Space Age.
PAUL
Once spacecraft began imaging the lunar farside, we discovered that it was very different from the near side. While the near side has lots of craters, maria, and mountain ranges, the farside is just battered with craters. The farside contains only 3% as much lunar maria as the near side. So why, astronomers have wondered, is the lunar farside so different than the near? One clue was the discovery that the crust on the farside is much thicker than the near side.
RACHEL
Perhaps a thicker crust makes it more difficult for subsurface magma to work its way to the surface and erupt as lava to create lunar maria. But why is the crust thicker here? One hypothesis is that left over material from the moon’s origin fell back on the lunar farside as a pancake of material. Another is that the still hot Earth prevented the moon’s near side from cooling down as quickly as the farside.
PAUL
That’s Idaho Skies for the 11th and 12th of February.
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 February 11th and 12th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
Hey, the moon reaches first quarter phase today.
PAUL
At first quarter, only the eastern half of the moon is visible. That’s because sunlight is also illuminating half of the moon’s farside. The boundary between day and night is called the moon’s terminator. It’s where sunrise is occurring on the moon. Since the sun is just rising along the terminator, shadows are especially long there. That makes it easier to see craters and mountains that reside along the terminator.
RACHEL
The moon has a near and far side because its day lasts 29 Earth days, the same time it takes for the moon to orbit Earth. Astronomers use the term tidally locked to describe this situation. Small moons are normally tidally locked to their host planet when the moons are close to the planet. Because it’s tidally locked, the lunar farside was luna incognita until the beginning of the Space Age.
PAUL
Once spacecraft began imaging the lunar farside, we discovered that it was very different from the near side. While the near side has lots of craters, maria, and mountain ranges, the farside is just battered with craters. The farside contains only 3% as much lunar maria as the near side. So why, astronomers have wondered, is the lunar farside so different than the near? One clue was the discovery that the crust on the farside is much thicker than the near side.
RACHEL
Perhaps a thicker crust makes it more difficult for subsurface magma to work its way to the surface and erupt as lava to create lunar maria. But why is the crust thicker here? One hypothesis is that left over material from the moon’s origin fell back on the lunar farside as a pancake of material. Another is that the still hot Earth prevented the moon’s near side from cooling down as quickly as the farside.
PAUL
That’s Idaho Skies for the 11th and 12th of February.
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, February 4, 2019
Idaho Skies Transcript for February 8th, 9th, and 10th
PAUL
Welcome to Idaho Skies for February 8th, 9th, and 10th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Mars and Uranus are very close together this week, but let’s start with an easier target, the moon.
RACHEL
By the evening of the 8th, the waxing crescent moon will appear in the low west-southwest after it gets dark. It’s four days old, or far enough away from the sun that stargazers will notice Earthshine illuminating its dark portion. This portion of the moon is experiencing night, so no direct sunlight is shining on it surface. The only light it receives is what was reflected from Earth.
PAUL
Use your binoculars. Earthshine can be seen with the unaided eye, but binoculars gather so much more light that you’ll be able to see surface features on the moon. Since Earthshine is not like morning sunlight, your binoculars won’t let you see details like craters and mountains. Instead, you’ll see maria or lunar seas. Look especially for a large round patch in the moon’s upper left. That will be Mare Imbrium, or the Sea of Rains.
RACHEL
This next object will definitely require your binoculars. Uranus the solar system’s sixth planet and it shines at a magnitude of 5.8. Now, good eyes and dark skies will let you see down to a slightly fainter 6th magnitude. But dark skies are not what we have in the Treasure Valley. However, if you get out from under your local street light, binoculars will let you see objects fainter than Uranus – if you know where to look.
PAUL
This is why the moon and Mars will come in handy on Sunday the 10th. At around 8:00 PM, aim your binoculars at the moon. Then place the moon on the left side of your binoculars. Mars will appear as the orangish star on the right, so you can’t miss it. Notice that Mars is the top star in an equilateral triangle of stars that spans about 1/4th of your binocular’s field of view. The fainter of the three stars in this triangle is Uranus. You’ll find a star map on our twitter account.
RACHEL
That’s Idaho Skies for the 8th, 9th, and 10th of February.
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 February 8th, 9th, and 10th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Mars and Uranus are very close together this week, but let’s start with an easier target, the moon.
RACHEL
By the evening of the 8th, the waxing crescent moon will appear in the low west-southwest after it gets dark. It’s four days old, or far enough away from the sun that stargazers will notice Earthshine illuminating its dark portion. This portion of the moon is experiencing night, so no direct sunlight is shining on it surface. The only light it receives is what was reflected from Earth.
PAUL
Use your binoculars. Earthshine can be seen with the unaided eye, but binoculars gather so much more light that you’ll be able to see surface features on the moon. Since Earthshine is not like morning sunlight, your binoculars won’t let you see details like craters and mountains. Instead, you’ll see maria or lunar seas. Look especially for a large round patch in the moon’s upper left. That will be Mare Imbrium, or the Sea of Rains.
RACHEL
This next object will definitely require your binoculars. Uranus the solar system’s sixth planet and it shines at a magnitude of 5.8. Now, good eyes and dark skies will let you see down to a slightly fainter 6th magnitude. But dark skies are not what we have in the Treasure Valley. However, if you get out from under your local street light, binoculars will let you see objects fainter than Uranus – if you know where to look.
PAUL
This is why the moon and Mars will come in handy on Sunday the 10th. At around 8:00 PM, aim your binoculars at the moon. Then place the moon on the left side of your binoculars. Mars will appear as the orangish star on the right, so you can’t miss it. Notice that Mars is the top star in an equilateral triangle of stars that spans about 1/4th of your binocular’s field of view. The fainter of the three stars in this triangle is Uranus. You’ll find a star map on our twitter account.
RACHEL
That’s Idaho Skies for the 8th, 9th, and 10th of February.
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 February 6th and 7th
RACHEL
Welcome to Idaho Skies for February 6th and 7th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon finally reappears in the evening sky this week.
PAUL
The moon was new on the 4th. That day, it passed above the sun from Idaho’s perspective. That meant there was no solar eclipse, since the moon didn’t pass in front of the sun. That also meant that sunlight fully illuminated the moon’s far side, while the near side that we see was left in complete darkness. People are being careless when they call the far side of the moon its dark side. It’s not dark; it gets two weeks of sunlight per month just like the near side.
RACHEL
Sometimes, stargazers can see the moon when it’s less than 24 hours after new. There are three astronomical conditions that improve your chances of seeing a moon this young. First, the moon must be closer to Earth than average, that way it travels swiftly away from the sun from our perspective. Second, new moon must occur between December and March. That way the moon’s orbit, relative to the horizon, tilts at its highest angle.
PAUL
The last condition takes advantage of the moon’s tilted orbit, which is tilted 5 degrees relative to Earth’s equator. This means it’s easier to see a young crescent moon when it’s at the highest point of its tilted orbit. So what is the youngest moon that stargazers have observed? Well, if we only count times that it was observed without optical aid, that would be 15.5 hours old.
RACHEL
Unfortunately, this month the moon is poorly placed for an early observation. However, stargazers will be able to observe the two-day old moon on the 6th. Look in the low west-southwest at about 7:00 PM. The thin crescent will probably be easier to find if you scan the area with your binoculars first. But please, wait until after sunset before you use binoculars anywhere close to the sun.
PAUL
That’s Idaho Skies for the 6th and 7th of February.
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 February 6th and 7th. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
The moon finally reappears in the evening sky this week.
PAUL
The moon was new on the 4th. That day, it passed above the sun from Idaho’s perspective. That meant there was no solar eclipse, since the moon didn’t pass in front of the sun. That also meant that sunlight fully illuminated the moon’s far side, while the near side that we see was left in complete darkness. People are being careless when they call the far side of the moon its dark side. It’s not dark; it gets two weeks of sunlight per month just like the near side.
RACHEL
Sometimes, stargazers can see the moon when it’s less than 24 hours after new. There are three astronomical conditions that improve your chances of seeing a moon this young. First, the moon must be closer to Earth than average, that way it travels swiftly away from the sun from our perspective. Second, new moon must occur between December and March. That way the moon’s orbit, relative to the horizon, tilts at its highest angle.
PAUL
The last condition takes advantage of the moon’s tilted orbit, which is tilted 5 degrees relative to Earth’s equator. This means it’s easier to see a young crescent moon when it’s at the highest point of its tilted orbit. So what is the youngest moon that stargazers have observed? Well, if we only count times that it was observed without optical aid, that would be 15.5 hours old.
RACHEL
Unfortunately, this month the moon is poorly placed for an early observation. However, stargazers will be able to observe the two-day old moon on the 6th. Look in the low west-southwest at about 7:00 PM. The thin crescent will probably be easier to find if you scan the area with your binoculars first. But please, wait until after sunset before you use binoculars anywhere close to the sun.
PAUL
That’s Idaho Skies for the 6th and 7th of February.
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 February 4th and 5th
PAUL
Welcome to Idaho Skies for February 4th and 5th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Forty-five years ago this Tuesday, Mariner 10 became the first spacecraft to use gravity assist to reach a second planet.
RACHEL
The Mariner 10 spacecraft was built by the Jet Propulsion Laboratory and designed to explore the inner solar system. Specifically, its mission was to visit the planets Venus and Mercury. It was the last of the Mariner spacecraft, a series of spacecraft famous for being the first ones to visit the inner planets.
PAUL
The Mariner series began in 1962 and ended with the launch of Mariner 10 in 1973. Not all the Mariners completed their missions. Three of them failed because of problems with their booster rockets. The first successful Mariner was number 2, which flew past Venus to become the first interplanetary space mission. Another one, Mariner 9, was the first spacecraft to enter orbit around another planet – Mars in this case.
RACHEL
Mariner 10 is famous because it was the first spacecraft to visit two planets, Venus and Mercury. Since Mariner 10 was launched from Earth, it had to lose a lot of potential energy to reach Mercury. Earth orbits the sun at a speed of 19 miles per second while Mercury orbits the sun at 29 miles per second. So losing enough potential energy to fall to Mercury’s distance from the sun meant Mariner 10 also increased speed by 50%.
PAUL
To reach Mercury, Mariner 10 had to slow down in order to fall closer to the sun. However, its rocket couldn’t provide enough thrust to both reach Earth orbit and then slow the spacecraft down to reach Mercury. Mariner 10 instead used the gravity of Venus to rob enough of its potential energy to fall even closer to the sun. And this was the first time that a spacecraft had used a gravity assist to change its orbit like this.
RACHEL
That’s Idaho Skies for the 4th and 5th of February.
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 February 4th and 5th. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Forty-five years ago this Tuesday, Mariner 10 became the first spacecraft to use gravity assist to reach a second planet.
RACHEL
The Mariner 10 spacecraft was built by the Jet Propulsion Laboratory and designed to explore the inner solar system. Specifically, its mission was to visit the planets Venus and Mercury. It was the last of the Mariner spacecraft, a series of spacecraft famous for being the first ones to visit the inner planets.
PAUL
The Mariner series began in 1962 and ended with the launch of Mariner 10 in 1973. Not all the Mariners completed their missions. Three of them failed because of problems with their booster rockets. The first successful Mariner was number 2, which flew past Venus to become the first interplanetary space mission. Another one, Mariner 9, was the first spacecraft to enter orbit around another planet – Mars in this case.
RACHEL
Mariner 10 is famous because it was the first spacecraft to visit two planets, Venus and Mercury. Since Mariner 10 was launched from Earth, it had to lose a lot of potential energy to reach Mercury. Earth orbits the sun at a speed of 19 miles per second while Mercury orbits the sun at 29 miles per second. So losing enough potential energy to fall to Mercury’s distance from the sun meant Mariner 10 also increased speed by 50%.
PAUL
To reach Mercury, Mariner 10 had to slow down in order to fall closer to the sun. However, its rocket couldn’t provide enough thrust to both reach Earth orbit and then slow the spacecraft down to reach Mercury. Mariner 10 instead used the gravity of Venus to rob enough of its potential energy to fall even closer to the sun. And this was the first time that a spacecraft had used a gravity assist to change its orbit like this.
RACHEL
That’s Idaho Skies for the 4th and 5th of February.
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.
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