Idaho Skies Transcript for the weekend of February 14th

STEPHEN

Welcome to Idaho Skies for the weekend of February 14^th. We’re your hosts, Stephen…

DAN

…and Dan.

STEPHEN

The moon reaches the third quarter phase this weekend, so it’s a perfect time to go moon gazing with your binoculars. The only problem is that you need to go outside after midnight to see it. But hey, it’s a weekend, so no problem. Observing the moon however will more convenient for listeners who get up before sunrise.

DAN

At third quarter, we’re able to see the moon’s western hemisphere. This hemisphere contains the moon’s largest feature, the Ocean of Storms. The Ocean of Storms is that lunar sea covering most of its western edge. Its 1,600 miles from the north to the south, or nearly the same height as the continental United States. 

STEPHEN

On the morning of the 15^th, the last quarter moon appears next to a star in Libra the Scales named Zubenelgenubi. This funny sounding name means the Southern Claw. The name doesn’t make sense for a constellation representing a set of scales for weighing objects. However, the star originally belonged to Scorpius the Scorpion. 

DAN

Most stars, like Zubenelgenubi are multiple stars, or stars in orbit around each other. However, it’s a special double star. That’s because its stars are so different (distant) from each other and the pair is so close to the solar system. This combination makes the pair appear farther apart than most double stars. So aim your binoculars at the star to the moon’s right and see if you see double.    

STEPHEN

That’s Idaho Skies for the weekend of February 14^th.   

DAN

Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Dan…

STEPHEN

…and Stephen.

DAN

Dark skies and bright stars.

Idaho Skies Transcript for the week of February 10th

PAUL

Welcome to Idaho Skies for the week of February 10^th. We’re your hosts, Paul…

STEPHEN

…and Stephen.

PAUL

Tiny Mercury makes an appearance this week. Few people have seen this elusive planet because it never appears very far above the horizon. This week however, the planet reaches its highest elevation above the western horizon. The planet can be quite bright, so it’s not difficult to see, if you know where to look.   

STEPHEN

Use Venus as your guide. Go outside at 7:00 PM and look for Venus, or the Evening Star. It’s the brightest object in the west-southwest, so you can’t miss it. Mercury, which is closer to the sun, is located to the lower right of Venus. Mercury is the only object appearing below Venus and at a point due west above the horizon.  

PAUL

Mercury is a small rocky world with a diameter of 3,000 miles. That makes it a bit larger than the moon and less than half the size of the Earth. Without an atmosphere, the surface of Mercury is pummeled with meteoroids. Its surface is so cratered than it easy to mistake Mercury for the moon. 

STEPHEN

Mercury was first visited by the Mariner 10 spacecraft in 1974. The 1,000-pound spacecraft didn’t carry enough propellant to slow down. That means Mariner 10 flew past Mercury collecting data and pictures. However, Mariner 10 was in orbit around the sun, so the spacecraft was able to visit Mercury two additional times.

PAUL

That’s Idaho Skies for the week of February 10^th.  

STEPHEN

Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Stephen…

PAUL

…and Paul.

STEPHEN

Dark skies and bright stars.

Idaho Skies Transcript for the weekend of February 7th

BENJAMIN

Welcome to Idaho Skies for the weekend of February 7^th. We’re your hosts, Benjamin…

PAUL

…and Paul.

BENJAMIN

On the last show, we talked about globular star clusters. This week, the moon passes close to a galactic star cluster and we think listeners should observe it. So let’s talk about these star clusters and how to see a nice one this week. Imagine before the invention of the telescope, when people only saw a small and fuzzy cloud in (the) Cancer the Crab.  

PAUL

This nebula was called the Praesepe. It was pictured as a manager holding hay for two donkeys. In this story, the donkeys were represented by the two faint stars next to the nebula. Until Galileo observed this fuzzy patch with his telescope, that’s all the ancients knew of it. When Galileo aimed a telescope at it, he counted over 40 stars inside of this cluster.      

BENJAMIN

Galileo’s telescope was too small to see the over 1,000 stars making up the Praesepe. He also didn’t know that the stars in the Praesepe formed together from the same cloud of dust and gas some 650 million years ago. Because of its large size and low density, the stars of the Praesepe cluster will eventually escape the cluster.       

PAUL

You still have lots of time to see this cluster, however. So aim your binoculars at the moon on the 8^th after it rises well above the eastern horizon. If the moon is at the top of your view, then the Praesepe will be located just beneath the center of your view. Once you see this cluster through binoculars, you’ll realize why it’s now called the Beehive star cluster.   

BENJAMIN

That’s Idaho Skies for the weekend of February 7^th.

PAUL

Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Paul…

BENJAMIN

…and Benjamin.

PAUL

Dark skies and bright stars.

Idaho Skies Transcript for the week of February 3rd

DAN

Welcome to Idaho Skies for the week of February 3^rd. We’re your hosts, Dan…

BENJAMIN

…and Benjamin.

DAN

On Monday night, the moon drifts through the edge of the Hyades star cluster. The Hyades is one of the largest star clusters in our sky. Star clusters like this are called galactic star clusters and they formed recently from a cloud of dust and gas. Over time, the dust and gas dissipates and the stars drift apart.

BENJAMIN

Galactic star clusters have the appearance of a random scattering of stars. This is the opposite of another type of star cluster, the globular star cluster. Globulars are spherical in shape and much older than galactics. Sadly, there are no globular star clusters close enough to appear as anything but a fuzzy spot through binoculars.

DAN

If the sun was a member of a globular star cluster, then our night-time sky would be filled with thousands of bright stars. There would be no night, and the sky would always be filled with light. Unfortunately, there may be no planets inside of globular clusters. That’s because of the typical age of globular star clusters.     

BENJAMIN

Globular star clusters are filled with old stars, formed when only hydrogen and helium filled the universe. Over time, these early stars fused elements into heavier ones like carbon, oxygen, and iron. But without these heavier elements, planets and even life can’t form. So chances are that no one is enjoying the amazing view inside of a globular cluster.

DAN

That’s Idaho Skies for the week of February 3^rd.   

BEJAMIN

Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Benjamin…

DAN

…and Dan.

BENJAMIN

Dark skies and bright stars.

Idaho Skies Transcript for the weekend of January 31st

STEPHEN

Welcome to Idaho Skies for the weekend of January 31^st. We’re your hosts, Stephen…

DAN

…and Dan.

STEPHEN

The moon is at the perfect phase this weekend. That’s the first quarter moon, or when Earth can only see half of the illuminated moon. Remember,  that half of the moon is always experience day. However, this weekend, half of the illuminated side is located on the far side and thus we cannot see it.  

DAN

What makes the first quarter moon so perfect for observing is that the shadows cast by the rising sun appear stretched out to their maximum extent. And those shadows are visible along the lunar terminator.

ARNOLD

I’ll be back

DAN

No, not that kind of terminator. Astronomically speaking, the terminator is the boundary between day and night. And when it’s turned face on to Earth, shadows appear at their greatest angular extent.

STEPHEN

Scan this area with your binoculars or small telescope this weekend. You’ll see mostly craters in the moon’s Southern Hemisphere and lunar seas in the north. Those lunar seas are ringed with mountains where the lunar crust was thrown back by massive impacts billions of years ago.    

DAN

There’s an extra treat on Sunday. That night the moon will be flanked by two star clusters, the Pleiades and the Hyades. The Pleiades is the smaller of the two and it’s a wonderful target for binoculars. The star cluster is 444 light years away. So the Pleiades that you see tonight is what it looked like in 1576.

STEPHEN

That’s Idaho Skies for the weekend of January 31^st.    

DAN

Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com

For Idaho Skies this is Dan…

STEPHEN

…and Stephen.

DAN

Dark skies and bright stars.

Idaho Skies Transcript for the week of January 27th

PAUL

Welcome to Idaho Skies for the week of January 27^th. We’re your hosts, Paul…

STEPHEN

…and Stephen.

PAUL

German astronomer Johannes Hevelius was born on the 28^th in 1611. Since most of our listeners are not familiar with this astronomer, let’s talk about him and his telescopes. Johannes was originally a beer brewer. Then after studying jurisprudence, he settled down in his hometown to become an astronomer. 

STEPHEN

In 1641, Johannes started building telescopes on the roofs of building. Since lens back then were of poor quality, astronomers had to compensate by increasing their focal lengths. For example, one of Johannes’ first long telescopes was twelve feet long. And his telescopes were about to get a lot larger than that.     

PAUL

And by large, we mean large. Johannes eventually made telescopes 60 and 70 feet long. He even built a telescope 150 feet long in 1673. These were called aerial telescopes and they had open tubes. The lenses were held in place with a series of wires. It took a crew to move these telescopes around. 

STEPHEN

Johannes was encouraged to use his telescopes to collect data. Unfortunately, the long and cumbersome telescopes were not a good fit for this. Nonetheless, he did spend four years making lunar maps. They were spectacular for the time and today we still consider Johannes the founder of lunar topography.

PAUL

That’s Idaho Skies for the week of January 27^th.   

STEPHEN

Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Stephen…

PAUL

…and Paul.

STEPHEN

Dark skies and bright stars.

Idaho Skies Transcript for the Weekend of January 17th

STEPHEN

Welcome to Idaho Skies for the weekend of January 17^th. We’re your hosts, Stephen…

DAN

…and Dan.

STEPHEN

The moon reaches third quarter on the 17^th. Late sleepers and early risers will find the half full moon in the east while it’s still dark. Since the moon is half full, the shadows cast by the rising sun strongly accentuate lunar features like craters and mountains. Stargazers with binoculars will want to aim them at the moon on the 17^th.   

DAN

Lunar craters where one time thought to be volcanic in nature. Observations of bullets striking the ground gave no indication that craters could form from impacts. The error was assuming that a “slow” bullet behaved like a meteoroid colliding with the ground at hypersonic speeds.  

STEPHEN

At impact though, a meteoroid vaporizes the ground in the immediate area. Land farther away gets peeled back and then flipped over. This means the closer an astronaut walks to a crater’s rim, the deeper the rock layers originated. Therefore, one need not actually climb down into a crater to get deep rock samples. 

DAN

Many of the craters you’ll see on the moon formed during the late heavy bombardment, or around 3.8 billion years ago. This was a time when planets and moons were sweeping up planetary building blocks. These building blocks are called planetesimals and they condensed from the original gas and dust of the solar system.

STEPHEN

That’s Idaho Skies for the weekend of January 17^th.   

DAN

Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Dan…

STEPHEN

…and Stephen.

DAN

Dark skies and bright stars.

Idaho Skies Transcript for the Week of January 13th

PAUL

Welcome to Idaho Skies for the week of January 13^th. We’re your hosts, Paul…

STEPHEN

…and Stephen.

PAUL

Fifteen years this Tuesday, the Huygens space probe landed on Titan. So let’s talk about Huygens and Titan. But first, the Cassini spacecraft was launched to Saturn back in October 1997. The spacecraft then spent 6.5 years traversing the solar system to reach Saturn. Once there, it fired its thrusters and entered orbit.

STEPHEN

On December 25^th 2004, Cassini released the Huygens probe. Huygens was riding piggy-back on the spacecraft and didn’t carry its own set of thrusters. This means Cassini had to aim for Titan before the release and then fire its thrusters afterwards to miss Titan. Titan by the way is Saturn’s largest moon.

PAUL

What makes Titan so special and interesting is that it has a dense atmosphere. In fact, it’s 50% denser than our atmosphere. Like our atmosphere, Titan’s is mostly nitrogen. Unlike ours, Titan’s atmosphere has no oxygen and its freezing cold. On its surface, the temperature is -290 degrees Fahrenheit.  

STEPHEN

Huygens returned images of an icy landscape of hills, dunes, and drainage patterns. Since Titan’s surface is bitterly cold, water ice is as hard as granite. Methane, a gas also on Earth, is a liquid on Titan. The moon therefore has a geological cycle of water and a hydrological cycle of methane. Still, Huygens returned landscape images looking very similar to Earth. 

PAUL

That’s Idaho Skies for the week of January 13^th.  

STEPHEN

Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Stephen…

PAUL

…and Paul.

STEPHEN

Dark skies and bright stars.

Idaho Skies Transcript for the Weekend of January 10th

STEPHEN

Welcome to Idaho Skies for the weekend of January 10^th. We’re your hosts, Stephen…

PAUL

…and Paul.

STEPHEN

Hey, the moon is full on the 10^th. Did you know that some Native American tribes named the first full moon of January the Wolf Moon? They did because on cold winter nights, wolves are hungrier than usual. So the people of these cultures would hear wolves howling more frequently at night.

PAUL

The full moon illuminates the sky and washes away all the fainter stars. That means the nights near the full moon are bad times to look for faint and fuzzy astronomical objects like comets and nebulae. Therefore, check out the sky tonight and see how the moon’s light changes the sky from dark black to grayish blue.  

STEPHEN

Then get out your binoculars for the night of the 11^th. The Beehive star cluster will be three degrees to the upper right of the moon. Since binoculars have a field of view of 7.5 degrees, both the moon and star cluster will appear together. However, it will be better if you shift the moon out of the field of view.

PAUL

The Beehive star cluster appears as large as the moon, so it’s not very small. You’ll see a compact groping of some two dozen stars, once the moon is out of sight. People call this star cluster the Beehive because it has a strong resemblance to bees buzzing around their hive. Do you see the same thing?   

STEPEN

That’s Idaho Skies for the weekend of January 10^th.

PAUL

Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com.

For Idaho Skies this is Paul…

STEPHEN

…and Stephen.

PAUL

Dark skies and bright stars.

Idaho Skies Transcript for the Week of January 6th

DAN

Welcome to Idaho Skies for the week of January 6^th. We’re your hosts, Dan…

PAUL

…and Paul.

DAN

Earth just passed perihelion this week. So let’s discuss perihelion and what it means for Earth. Perihelion is that point in an elliptical orbit that is closest to the sun. At perihelion, Earth is only 91 million, 343 thousand miles from the sun. Or about 2% closer than average.

PAUL

Even though Earth receives about 7% more sunlight at perihelion, it occurs over the Southern Hemisphere. The Southern Hemisphere, which is covered mostly by water, is difficult to warm up. Therefore, all that extra sunlight can’t warm air temperatures in the Southern Hemisphere very significantly.  

DAN

On the 7^th, stargazers will find the waxing gibbous moon near the eye of the celestial bull. That bull is named Taurus and his eye is named Aldebaran. Taurus is an old constellation. In fact, this pattern of stars was recognized as a bull all the way back to the Bronze Age, over 6,000 years ago.    

PAUL

The distance between the moon and Aldebaran is five degrees. Since binoculars have a field of view of around 7.5 degrees, the moon and Aldebaran will be seen together. But notice that Aldebaran has company. To the right of Aldebaran and a little above are the stars of the Hyades star cluster.

DAN

That’s Idaho Skies for the week of January 6^th.  

PAUL

Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.

For Idaho Skies this is Paul…

DAN

…and Dan.

PAUL

Dark skies and bright stars.