RACHEL
Welcome to Idaho Skies for December 14th, 15th, and 16th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The crescent moon passes just below the Red Planet on the 14th.
PAUL
Mars will be the orangish star you see above the moon after dark on the 14th. The moon is 242,000 miles away while Mars is 103 million miles away. Whereas the moon will show attractive detail through binoculars, Mars is too small and far away to show anything through binoculars. Both however, are worlds where automated robots have traversed.
RACHEL
The first robot to travel on another world was the Soviet Lunokhod 1 and it landed on the moon November 17th, 1970. Lunokhod 1 was solar powered and operated under human control back on Earth. A drive team sent commands to the rover for 321 days before it failed. In that time, the rover drove a distance of 6.4 miles.
PAUL
The first robot to land on Mars was the American Sojourner robot and it landed on Mars on July 4th, 1997. Sojourner was also solar powered and instructed by a team on Earth. Unlike Lunokhod, drivers could not operate Sojourner in near real time. That’s because the time it takes for a signal to travel to Mars is too great. So the American team radioed a series of instructions to Sojourner to carry out as best as it could.
RACHEL
Did you know there’s a robot operating on an asteroid? The Japanese Aerospace Exploration Agency dropped two robots on an asteroid named Ryugu. The gravity on this asteroid is so weak that wheeled robots cannot get enough traction to drive across the surface. The robots are named MINERVA-2 1A and 1B and they hop across the surface. Each hop might take 15 minutes to complete because of the incredibly weak gravity of this tiny asteroid.
PAUL
That’s Idaho Skies for the 14th, 15th, and 16th of December.
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, December 10, 2018
Idaho Skies Transcript for December 12th and 13th
PAUL
Welcome to Idaho Skies for December 12th and 13th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The Geminid meteor shower reaches its peak this week.
RACHEL
The Geminid meteor shower is reliable meteor shower
PAUL
Most meteor showers originate as dust from comet tails. The Geminids actually originate from dust chipped off an asteroid. The dust of a meteor shower is small, at about the size of a grain of sand or perhaps grain of rice. When these dust motes slam into Earth’s atmosphere, they are traveling far faster than the speed of sound. This means air molecules ahead of them don’t have time to move out of the way before the dust mote has arrived.
RACHEL
This compresses the air ahead of the dust mote so fast that the air gets very hot. Think of it this way. You compress the air in a bicycle pump when you fill a tire with air. Now image how hot the pump would get if you were to operate it at thousands of miles per hour. The air inside the pump would get so hot that it would melt the pump.
PAUL
The moon sets by 11:30 PM on the 13th. So if you go outside around then, you should see Geminid meteors streaking out of the high east. Look for dozens of meteors per hour from this shower, especially if you observe it from a dark location. The meteors from this shower will have a slightly yellow tint and don’t travel quite as swiftly as those in other meteor showers. Just be sure to dress warmly.
RACHEL
That’s Idaho Skies for the 12th and 13th of December.
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 December 12th and 13th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The Geminid meteor shower reaches its peak this week.
RACHEL
The Geminid meteor shower is reliable meteor shower
PAUL
Most meteor showers originate as dust from comet tails. The Geminids actually originate from dust chipped off an asteroid. The dust of a meteor shower is small, at about the size of a grain of sand or perhaps grain of rice. When these dust motes slam into Earth’s atmosphere, they are traveling far faster than the speed of sound. This means air molecules ahead of them don’t have time to move out of the way before the dust mote has arrived.
RACHEL
This compresses the air ahead of the dust mote so fast that the air gets very hot. Think of it this way. You compress the air in a bicycle pump when you fill a tire with air. Now image how hot the pump would get if you were to operate it at thousands of miles per hour. The air inside the pump would get so hot that it would melt the pump.
PAUL
The moon sets by 11:30 PM on the 13th. So if you go outside around then, you should see Geminid meteors streaking out of the high east. Look for dozens of meteors per hour from this shower, especially if you observe it from a dark location. The meteors from this shower will have a slightly yellow tint and don’t travel quite as swiftly as those in other meteor showers. Just be sure to dress warmly.
RACHEL
That’s Idaho Skies for the 12th and 13th of December.
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 December 10th and 11th
RACHEL
Welcome to Idaho Skies for December 10th and 11th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
There are three crescents in the sky this week.
PAUL
The first you can se without optical aid. It’s the young crescent moon or more specifically, the waxing crescent moon. Stargazers will find the moon in the low southwest after sunset. Since the moon is only four days old and traveling slowly away from the sun from our perspective, it remains a very thin crescent. This increases your chances of seeing earthshine for the next few nights. .
RACHEL
Next is Venus. Stargazers will see the Morning Star in the southeast as they drive to work in the morning. Venus is so bright that you can’t mistake it for anything other than Venus. Right now Venus is too far form Earth to show a crescent shape in binoculars. But a small telescope or even spotting scope has the necessary magnification to do so.
PAUL
Much closer to the horizon is innermost planet Mercury. It too is located between Earth and the sun. This means its phase is crescent shaped. Mercury is swiftly traveling to the other side of the sun from our perspective. This is why the planet will climb slightly higher and grow fainter over the next few weeks.
RACHEL
In a telescope, you would see Mercury become fuller and smaller as it travels to the other side of the solar system. Jupiter, which is also on the other side of the solar system, is much farther away than Mercury. So form Jupiter’s perspective, Mercury is approaching closer to the sun and becoming more crescent shaped.
PAUL
That’s Idaho Skies for the 10th and 11th of December.
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 December 10th and 11th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
There are three crescents in the sky this week.
PAUL
The first you can se without optical aid. It’s the young crescent moon or more specifically, the waxing crescent moon. Stargazers will find the moon in the low southwest after sunset. Since the moon is only four days old and traveling slowly away from the sun from our perspective, it remains a very thin crescent. This increases your chances of seeing earthshine for the next few nights. .
RACHEL
Next is Venus. Stargazers will see the Morning Star in the southeast as they drive to work in the morning. Venus is so bright that you can’t mistake it for anything other than Venus. Right now Venus is too far form Earth to show a crescent shape in binoculars. But a small telescope or even spotting scope has the necessary magnification to do so.
PAUL
Much closer to the horizon is innermost planet Mercury. It too is located between Earth and the sun. This means its phase is crescent shaped. Mercury is swiftly traveling to the other side of the sun from our perspective. This is why the planet will climb slightly higher and grow fainter over the next few weeks.
RACHEL
In a telescope, you would see Mercury become fuller and smaller as it travels to the other side of the solar system. Jupiter, which is also on the other side of the solar system, is much farther away than Mercury. So form Jupiter’s perspective, Mercury is approaching closer to the sun and becoming more crescent shaped.
PAUL
That’s Idaho Skies for the 10th and 11th of December.
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, December 3, 2018
Idaho Skies Transcript for December 7th, 8th, and 9th
PAUL
Welcome to Idaho Skies for December 7th, 8th, and 9th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon was new on the afternoon of the 6th.
RACHEL
So very observant stargazers might be able to find a 34-hour old moon during dusk on the 8th. However, you’ll need a very clear and flat southwestern horizon if you want to see this very thin crescent moon. Binoculars will be of help also. But please do not go scanning the horizon with binoculars until after the sun sets. It’s too easy to actually scan across the sun before it sets.
PAUL
What might help you find the moon is Saturn. Saturn is the faint star in the low southwest at 7:00 PM on the 8th. It will be the only noticeable star this close to the horizon, but will benefit from your use of binoculars. Saturn will disappear from the evening sky in another two weeks, so around the 8th would be a good time to look for this planet before it becomes a morning planet in mid-January next year.
RACHEL
Once you locate Saturn in your binoculars scan a little bit to its right for the moon. The distance between Saturn and the moon is three degrees, or less than half the field of view your binoculars. So if you place Saturn on the left edge of your binoculars, the moon will be almost exactly in the center. Even though the moon and Saturn appear close together, they’re no where near one another.
PAUL
That’s right. The moon is only 244,000 miles away from us. Saturn on the other hand is one billion miles away, or 4,170 times farther away. We lose a sense of distance when looking at the night sky. Therefore, it’s not surprising that ancient cultures pictured the sky as a dome over the land. One of the great discoveries of astronomy is that the distance to astronomical objects is, well, astronomical.
RACHEL
That’s Idaho Skies for the 7th, 8th, and 9th of December.
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 December 7th, 8th, and 9th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
The moon was new on the afternoon of the 6th.
RACHEL
So very observant stargazers might be able to find a 34-hour old moon during dusk on the 8th. However, you’ll need a very clear and flat southwestern horizon if you want to see this very thin crescent moon. Binoculars will be of help also. But please do not go scanning the horizon with binoculars until after the sun sets. It’s too easy to actually scan across the sun before it sets.
PAUL
What might help you find the moon is Saturn. Saturn is the faint star in the low southwest at 7:00 PM on the 8th. It will be the only noticeable star this close to the horizon, but will benefit from your use of binoculars. Saturn will disappear from the evening sky in another two weeks, so around the 8th would be a good time to look for this planet before it becomes a morning planet in mid-January next year.
RACHEL
Once you locate Saturn in your binoculars scan a little bit to its right for the moon. The distance between Saturn and the moon is three degrees, or less than half the field of view your binoculars. So if you place Saturn on the left edge of your binoculars, the moon will be almost exactly in the center. Even though the moon and Saturn appear close together, they’re no where near one another.
PAUL
That’s right. The moon is only 244,000 miles away from us. Saturn on the other hand is one billion miles away, or 4,170 times farther away. We lose a sense of distance when looking at the night sky. Therefore, it’s not surprising that ancient cultures pictured the sky as a dome over the land. One of the great discoveries of astronomy is that the distance to astronomical objects is, well, astronomical.
RACHEL
That’s Idaho Skies for the 7th, 8th, and 9th of December.
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 December 5th and 6th
RACHEL
Welcome to Idaho Skies for December 5th and 6th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
We mentioned last time that Mercury and Venus are visible together in the morning sky.
PAUL
Both Venus and Mercury are what astronomers call inferior planets. This means both orbit the sun in paths that are wholly inside Earth’s orbit. This means they experience a greater gravitational attraction to the sun than Earth. Therefore, they orbit the sun more quickly than Earth does. Since one orbit of the sun is a year, the length of the year for Mercury and Venus is shorter than Earth’s.
RACHEL
The length of a year on Mercury is 88 days. In other words, an Earth year lasts just over four Mercurian years and Mercury will celebrate the passing of another year on March 3rd. The length of a year for Venus is longer at 225 days. That makes a Venusian year only 62% as long as a terrestrial year. Venus will celebrate the passing of another year on July 18th.
PAUL
Mercury is a world that looks much like our moon. The planet’s diameter is 3,032 miles, or 38% the diameter of Earth and 142% the diameter of the moon. What atmosphere Mercury has is called an exosphere. Exospheres consist of molecules that are gravitational bound to a planet but so thinly spread out that they seldom ever collide with one another. The result is that the air pressure in an exosphere is essentially unmeasureably low.
RACHEL
Spacecraft and Earth-based telescopes have detected hydrogen, helium, oxygen, sodium, and potassium in Mercury’s exosphere. The hydrogen and helium almost certainly originate with the sun’s solar wind. The oxygen, sodium and potassium likely originate in the planet’s crust. They are released from Mercury the action of solar heat and wind.
PAUL
That’s Idaho Skies for the 5th and 6th of December.
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 December 5th and 6th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
We mentioned last time that Mercury and Venus are visible together in the morning sky.
PAUL
Both Venus and Mercury are what astronomers call inferior planets. This means both orbit the sun in paths that are wholly inside Earth’s orbit. This means they experience a greater gravitational attraction to the sun than Earth. Therefore, they orbit the sun more quickly than Earth does. Since one orbit of the sun is a year, the length of the year for Mercury and Venus is shorter than Earth’s.
RACHEL
The length of a year on Mercury is 88 days. In other words, an Earth year lasts just over four Mercurian years and Mercury will celebrate the passing of another year on March 3rd. The length of a year for Venus is longer at 225 days. That makes a Venusian year only 62% as long as a terrestrial year. Venus will celebrate the passing of another year on July 18th.
PAUL
Mercury is a world that looks much like our moon. The planet’s diameter is 3,032 miles, or 38% the diameter of Earth and 142% the diameter of the moon. What atmosphere Mercury has is called an exosphere. Exospheres consist of molecules that are gravitational bound to a planet but so thinly spread out that they seldom ever collide with one another. The result is that the air pressure in an exosphere is essentially unmeasureably low.
RACHEL
Spacecraft and Earth-based telescopes have detected hydrogen, helium, oxygen, sodium, and potassium in Mercury’s exosphere. The hydrogen and helium almost certainly originate with the sun’s solar wind. The oxygen, sodium and potassium likely originate in the planet’s crust. They are released from Mercury the action of solar heat and wind.
PAUL
That’s Idaho Skies for the 5th and 6th of December.
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 December 3rd and 4th
PAUL
Welcome to Idaho Skies for December 3rd and 4th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Early-rising stargazers will find a treat in the morning sky.
RACHEL
If you look in the low southeast on Wednesday morning, you’ll find a very old moon close to the horizon. A good time to look for this is around 8:15 AM, before the sky brightens too much form the rising sun. You’ll want binoculars to scan the low horizon and locate the moon.
PAUL
If you’re not sure where to look for the moon, then look for the Morning Star first. Brilliant Venus will be located three times higher in the southeast. Venus you can’t miss or confuse for another star because there’s nothing like it in the sky. Venus is leaving the far side of the sun and speeding ahead to get between Earth and the sun.
RACHEL
Venus and the moon aren’t your ultimate goals. Your goal is a star located below just a little distance beneath the moon. This is Mercury, the innermost planet of the solar system. Mercury will be faint compared to Venus, but it will be the only star to appear beneath the moon. If you find this sun-baked world, you’ll be in a small company of people. That’s because most people on planet Earth have never seen the planet Mercury.
PAUL
One would think that since Mercury is closer to the sun than Venus is, that Mercury would have the higher surface temperature. Actually, the hottest is the surface of Venus because of its massive atmosphere. This atmosphere is primarily carbon dioxide, a famous greenhouse gas. Because the pressure of the Venusian atmosphere is 90 times greater than Earth’s and almost entirely CO2, what heat reaches its surface and never escape.
RACHEL
That’s Idaho Skies for the 3rd and 4th of December.
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 December 3rd and 4th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Early-rising stargazers will find a treat in the morning sky.
RACHEL
If you look in the low southeast on Wednesday morning, you’ll find a very old moon close to the horizon. A good time to look for this is around 8:15 AM, before the sky brightens too much form the rising sun. You’ll want binoculars to scan the low horizon and locate the moon.
PAUL
If you’re not sure where to look for the moon, then look for the Morning Star first. Brilliant Venus will be located three times higher in the southeast. Venus you can’t miss or confuse for another star because there’s nothing like it in the sky. Venus is leaving the far side of the sun and speeding ahead to get between Earth and the sun.
RACHEL
Venus and the moon aren’t your ultimate goals. Your goal is a star located below just a little distance beneath the moon. This is Mercury, the innermost planet of the solar system. Mercury will be faint compared to Venus, but it will be the only star to appear beneath the moon. If you find this sun-baked world, you’ll be in a small company of people. That’s because most people on planet Earth have never seen the planet Mercury.
PAUL
One would think that since Mercury is closer to the sun than Venus is, that Mercury would have the higher surface temperature. Actually, the hottest is the surface of Venus because of its massive atmosphere. This atmosphere is primarily carbon dioxide, a famous greenhouse gas. Because the pressure of the Venusian atmosphere is 90 times greater than Earth’s and almost entirely CO2, what heat reaches its surface and never escape.
RACHEL
That’s Idaho Skies for the 3rd and 4th of December.
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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