Tuesday, January 22, 2019

Idaho Skies Transcript for January 25th, 26th, and 27th

PAUL
Welcome to Idaho Skies for January 25th, 26th, and 27th. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
The moon reaches the third quarter phase on the night of the 26th and morning of the 27th.

RACHEL
The third quarter moon will rise over Boise at 11:38 PM. That’s often too late for most people, but it is a weekend. If you aim your binoculars at the moon, you will notice a large round sea in the upper right of the moon. This is the Sea of Rains or Mare Imbrium. Along its lower right edge is the Apennine Mountains. You should also notice two large craters in this lunar sea.

PAUL
The large crater inside of the Sea of Rains is named Archimedes and the other one at the top is called Plato. Archimedes and Plato are very old craters that formed after a giant impact created the Sea of Rains. Astronomers know this because these craters have flat and dark interiors. In other words, they’re not bowl-shaped.

RACHEL
The decay of unstable elements led to the creation of magma, or liquid rock beneath the lunar surface. In time, the less dense magma oozed out of cracks or fissures in the Sea of Rains. That magma became sheets of lava that filled in the giant impact scar. It took many layers of lava to fill in the Sea of Rains. That’s why this lunar sea looks dark and is free of many large craters.

PAUL
Astronomers know that Archimedes and Plato formed after the impact that created the Sea of Rains and before lava filled in the impact site. If they had formed first, then the impact responsible for the Sea of Rains would have obliterated the craters. If they formed after the moon’s magma cooled, they would have never filled with lava. So when do astronomers think these craters were created? About 3.8 billion years ago. 

RACHEL
That’s Idaho Skies for the 25th, 26th, and 27th of January.

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 January 23rd and 24th

RACHEL
Welcome to Idaho Skies for January 23rd and 24th. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
On January 23rd, 1930, American astronomer Clyde Tombaugh was scanning photographic plates of the sky when he noticed a star that shifted its position between the plates.

PAUL
Tombaugh was a Kansas farm boy who the Lowell Observatory in Flagstaff, Arizona hired in 1929. The founder of the observatory was Percival Lowell and he was certain that there was a planet beyond Neptune, the most distantly known planet known at the time. Therefore, the observatory tasked Tombaugh with searching for this planet by taking photographs of the night sky.   

RACHEL
He was therefore searching for a star-like point that shifted it position from one night to the next just enough for a distant planet. To help him in his search, Tombaugh took pictures of the same star field several nights apart. He then loaded each photographic plate into a light box and then quickly alternated between the two plates. In his blink comparator, stars remained stationary, but moving objects jumped back and forth.

PAUL
He discovered a lot of asteroids this way. In fact, there were so many asteroids in photographic plates that astronomers called them the vermin of the sky. However, Tombaugh knew that a distant planet wouldn’t shift its position as much as an asteroid would. That’s because asteroids orbit closer to the sun and therefore, move more quickly.

RACHEL
Lowell had lucked out, there actually was a more distant planet, but not because of the reasons that he thought. The planet was eventually named Pluto after the Roman god of the underworld. And in 1999, Pluto lost its status as a planet to become the first Kuiper Belt object to be discovered. Eighty-five years after its discovery, the New Horizons spacecraft gave us our first close up look at Pluto when it flew by. 

PAUL
That’s Idaho Skies for the 23rd and 24th of January.

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 January 21st and 22nd

Welcome to Idaho Skies for January 21st and 22nd. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Early risers will notice two bright stars in the low east before they head to work.

RACHEL
The stars are actually planets, specifically, Jupiter and much brighter Venus. Venus is slowly climbing higher each day while Jupiter is rocketing up. Over the next several days, observant stargazers will notice significant changes in the relative positions between these two planets. Binoculars are useful in observing Jupiter, but not usually helpful with Venus. 

PAUL
On the 21st, binoculars will show what looks like two satellites on the right side of Jupiter and none on its left. However, look closely; the satellite closest to Jupiter is actually two, one just above the other. The bottom satellite is Europa and the one above it is Callisto. The satellite farthest away from Jupiter is Ganymede, the largest satellite in the solar system.

RACHEL
On the morning of the 22nd, binoculars will show two satellites on the right of Jupiter and perhaps one on its left. On the right are Ganymede close to Jupiter and Callisto farther away. Europa will have orbited to the other side of Jupiter. A small telescope will show a fourth satellite on Jupiter’s left, and closer to the planet than Europa. This is Io, which was in front of Jupiter the day before.

PAUL
On the night of the 22nd, stargazers will find a pale orange star next to the just past full moon. The star is Regulus, the brightest star in Leo the Lion. The lion is a spring constellation and has two distinct halves. The first begins with Regulus at the bottom of a backwards question mark of six stars. These represent the back of Leo’s mane. To the left, or east of Regulus is the second half. It’s a triangle of stars that represents the hindquarter of the lion.

RACHEL
That’s Idaho Skies for the 21st and 22nd of January.

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, January 14, 2019

Idaho Skies Transcript for January 18th, 19th, and 20th

RACHEL
Welcome to Idaho Skies for January 18th, 19th, and 20th. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
Idaho gets to see a total lunar eclipse this Sunday.

PAUL
The moon will be near its closest point to Earth for the month on Sunday. This means we get to see a Super Moon, or one that’s slightly larger and brighter than average. Even better, the moon will pass through the shadow cast by Earth. This will result in a lunar eclipse where the sun’s light is blocked from reaching the moon. The path the moon takes through Earth’s shadow goes close enough to its center that the entire moon will be covered in shadow.   

RACHEL
The eclipse should become visible by 8:30 PM. Depending on the clarity of Earth’s atmosphere, the moon could turn a bright coppery red or become as dark as charcoal. To an astronaut standing on the moon, Earth would drift in front of the sun and then turn into a bright fiery ring of light. Idaho stargazers can continue to observe the eclipse until about midnight when the last of Earths’ shadow will no longer be visible.

PAUL
A pair of binoculars is all you need to enjoy this lunar eclipse. In fact, a telescope would magnify too much. While you’re watching the eclipse, place the moon on the right edge of your binoculars. Then look near the left edge to see the Beehive star cluster. As the moon gets darker, the Beehive will become easier to see. Stargazers will see up to two dozen stars in this star cluster. And it will appear nearly the same size as the moon. 

RACHEL
Those with a serious digital camera might try photographing the eclipsed moon. Set your camera on a tripod and then zoom in on the moon. Only use optical and not digital zoom. You might try overriding the automatic focus and exposure of your camera, since it’s programmed for landscapes and people. Using a cable release is also a good idea. That way your hands won’t shake the camera when you take a picture.   

PAUL
That’s Idaho Skies for the 18th, 19th, and 20th of January.

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 January 16th and 17th

PAUL
Welcome to Idaho Skies for January 16th and 17th. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Watch the moon drift between two star clusters on the 16th and 17th.

RACHEL
On the 16th, stargazers will find the moon below the Pleiades and to the right of the Hyades. Both star clusters are large, so you only need binoculars to enjoy them. The Pleiades will appear as a tiny dipper while the Hyades appear as a large sideways V. That’s a big difference in size and shape. I guess this just goes to show that star clusters are like snow flakes; no two are alike. 

PAUL
On the night of the 17th, stargazers will find the moon on the other side of the Hyades. The moon and the brightest star in the Hyades will be close together. So close that you can see both at the same time through binoculars. The star’s name is Aldebaran, which is Arabic for the follower. It gets this name because it rises after both the Pleiades and Hyades star clusters. 

RACHEL
Aldebaran is 65 light years away. Did you know that Earths’ first starship was sent to this star? Actually, the spacecraft is the Pioneer 10 and its mission was to explore Jupiter. It did this back in 1973 during a fly-by mission. The immense gravity of Jupiter than flung the tiny spacecraft in the direction of Aldebaran. In about two million AD, the long defunct Pioneer 10 will sail past Aldebaran.

PAUL
Aldebaran is the 14th brightest star in the sky and the 9th brightest for stargazers living in Idaho. It’s an old and large star. Aldebaran has a core filled with helium ash and it’s surrounded with a shell of fusing hydrogen. Its high internal temperature has caused Aldebaran to swell up into a red giant star. In fact, this star has a diameter 44 times greater than the sun’s. This means that if it replaced the sun, little Mercury would be treading just outside the star’s surface. 

RACHEL
That’s Idaho Skies for the 16th and 17th of January.

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 January 14th and 15th

RACHEL
Welcome to Idaho Skies for January 14th and 15th. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
The moon just passed the first quarter phase. So get your binoculars or telescope out.

PAUL
Take a look to the moon’s upper right. That’s where you will find a dark oval called Mare Crisium, or the Sea of Crises. But it wasn’t always called by this name. Before 1651, it was known as the Caspian Sea. That’s probably because the Caspian Sea occupies the upper right corner of maps depicting Europe, Africa, and Asia. Back in 1600, British astronomer William Gilbert named it Brittania on his moon map. 

RACHEL
Jesuit astronomer Giovanni Riccioli published a moon map in 1651 that standardized the lunar place names. Giovanni was born in 1614, or five years after Galileo turned his newly made telescope towards the heavens (I made an error here, that’s the year he joined the Jesuit order). After his ordination in 1628, Giovanni became a teacher at the College of Parma in Italy. Did you know that Parma, Idaho was named after Parma, Italy? One of Parma’s famous residents was Edgar Rice Burroughs, the writer of the John Carter of Mars stories. 

PAUL
Giovanni had a greater interest in astronomy than theology. So his superiors assigned him the task of astronomical research. One of his research projects was testing how well a pendulum can keep time. Accurate clocks are very important in astronomical research. With the help of a second Jesuit astronomer, Francesco Grimaldi, Giovanni created a moon map for his book, the New Almagest. This map contained the names of lunar features as we have come to know them today. 

RACHEL
The large lunar seas, Giovanni named after the weather. Craters he named after important astronomers. The naming convention places the oldest astronomers at the top of the moon and more recent astronomers going clockwise around the moon from there. As a Jesuit, Giovanni couldn’t support the sun-centered universe. He claimed this is why he placed astronomers like Copernicus and Kepler in the Ocean of Storms. 

PAUL
That’s Idaho Skies for the 14th and 15th of January.

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, January 8, 2019

Idaho Skies Transcript for January 11th, 12th, and 13th

PAUL
Welcome to Idaho Skies for January 11th, 12th, and 13th. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Stargazers will find it very easy to locate Mars this Saturday.

RACHEL
Mars is the yellowish (orange) star appearing above the moon after it gets dark. Mars is a terrestrial planet, or one like Earth. That means it has a rocky surface and atmosphere. The combination of atmosphere and rocky crust makes Mars a very dusty place. The fine dust coating its surface doesn’t come from the presence of liquid water. Instead, it comes from the sand-blasting of rocks by wind, just as we find on Earth’s deserts.

PAUL
One thing that Mars does not have is a planet-wide magnetic field. Earth’s magnetic field covers the entire planet and extends far into space. Because of its size and strength, the field protects life from dangerous radiation and prevents the sun’s solar wind and radiation from blowing our atmosphere away. Without a strong magnetic field, Mars most likely lost its atmosphere billions of years ago from solar wind. 

RACHEL
The latest spacecraft to study Mars is the InSight Lander. It’s carrying a seismograph and heat flow experiment to measure the planet’s vital signs. These instruments will help NASA measure the size of the Martian core, its temperature, and whether or not it’s still molten. A molten core is important; because it appears that the flow of liquid metal within a spinning core creates a planet-wide magnetic field   

PAUL
The InSight lander safely deployed its seismograph last December. That event required its robotic arm to lift the seismograph off its deck and then move it to a location just over five feet away from the lander. By placing the seismograph directly on the Martian surface and far from the lander, the lander won’t contaminate its data with its shaking and vibration. The heat flow experiment has yet to be placed on the Martian surface. 

RACHEL
That’s Idaho Skies for the 11th, 12th, and 13th of January.

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 January 9th and 10th

RACHEL
Welcome to Idaho Skies for January 9th and 10th. We’re your hosts, Rachel…

PAUL
…and Paul.

RACHEL
All the matter in the universe began expanding at its birth, some 13.7 billion years ago.

PAUL
The expansion of space is carrying matter, like the galaxies with it. That means that while the galaxies are moving apart from one another, they don’t experience a sense of movement relative to space around them. However, the gravity exerted by the matter in galaxies can make them move independently of the expansion of the space between them.

RACHEL
Cosmologists have wondered if the gravitational force exerted by galaxies could pull them together faster than expanding space-time could carry them apart. Perhaps there’s enough matter in the universe to stop the relative motion between all the galaxies, even through space would continue to expand. Or maybe there’s enough matter to bring all the galaxies together in a great crunch some time in the distant future.

PAUL
To answer this question, astronomers began measuring the distance and speed of galaxies. They needed a tool bright enough to work across the universe and that tool was supernovae explosions. On January 9th, 1998, two teams of astronomers announced that very distant galaxies were farther apart than they expected. This is exactly the opposite behavior that cosmologists thought they would find.       

RACHEL
It appears that space has developed an anti-gravity property. Five billion years ago, space began pushing galaxies apart even faster. The force responsible for this behavior is still unknown, but not unpredicted. Einstein introduced a cosmological constant to into his math to keep the universe static, or free of expansion and collapse. Today we call it Dark Energy and for some reason, it began accelerating the expansion of the universe five billion years ago.

PAUL
That’s Idaho Skies for the 9th and 10th of January.

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 January 7th and 8th

PAUL
Welcome to Idaho Skies for January 7th and 8th. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
The moon was new on the 6th.

RACHEL
Stargazers will see it again if they look in the low southwest at around 7:00 PM on Tuesday the 8th. The moon will be nearly three days old, and therefore appear as a very thin crescent. The moon will be too thin to show any significant craters. Those that stargazers might see in their binoculars will appear nearly on edge. That means, very thin and elliptical.

PAUL
It will be easier to find the thin moon through binoculars. But to see it without optical aid is even neater. Remember when the moon is this thin, the majority of its far side is in daylight. That also means that an astronaut standing on the moon would see the Earth mostly full. The phase of the moon and Earth are opposite of each other to people standing on their surfaces. 

RACHEL
After you locate the moon, look for the star to the moon’s left. That star is Fomalhaut, the brightest star of the Southern Fish. Fomalhaut is only 440 million years old. That means its old enough to have planets and to have blown away any dust remaining from their formation. Since Fomalhaut is only 25 light years away, astronomers can use the Hubble Space Telescope to verify this prediction.

PAUL
Astronomers actually did found a planet, not just evidence of a planet. Even more surprising was the amount of dust still surrounding the star. The dust appears to be the result of comet collisions. Astronomers believe that it would take trillions of comets and thousands of collisions every day to create this amount of dust surrounding Fomalhaut. The USS Enterprise better raise its deflectors before entering this star system. 

RACHEL
That’s Idaho Skies for the 7th and 8th of January.

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.