PAUL
Welcome to Idaho Skies for the first week of November. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
NASA launched the first spacecraft to visit the solar system’s innermost planet forty years ago on the 3rd.
RACHEL
NASA first sent Mariner 10 to Venus so it could use the planet’s gravity to alter its course to approach Mercury. This made Mariner 10 the first spacecraft to use a planet’s gravity to alter its trajectory.
PAUL
During a gravitational assist, a spacecraft steals some of a planet’s kinetic energy or the planet steals some of a spacecraft’s kinetic energy.
RACHEL
The amount of kinetic energy traded between the spacecraft and planet is so tiny that the effects on the planet won’t become obvious for billions of years.
PAUL
However, because of the spacecraft’s tiny mass, the impact can be huge for the spacecraft.
RACHEL
Mariner 10 needed to lose some of its kinetic energy because it had too much to orbit as close to the sun as its destination, Mercury.
PAUL
As Mariner 10 approached Mercury on March 29, 1974, it used Mercury’s gravity to alter its course and pass the planet two additional times.
RACHEL
Gravity wasn’t the only way Mariner 10 altered its orbit.
PAUL
That’s right. The sun’s light is so intense near Mercury that it can push a spacecraft around like a sailboat.
RACHEL
Because of the timing of the spacecraft passages, Mariner 10 was only able to photograph 45% of the planet’s surface.
PAUL
The rest of Mercury remained a mystery until the arrival of the Messenger spacecraft.
RACHEL
Images returned by Mariner 10 and Messenger reveal that Mercury’s surface shares a strong similarity to the moon.
PAUL
Idaho will get a glimpse of Mercury next week.
RACHEL
Before that, you can observe the Taurid meteor shower.
PAUL
The best night is on the 3rd, when the meteor shower reaches its peak intensity.
RACHEL
The moon will be nearly new on the 3rd making it easier to see the fainter members of this shower.
PAUL
You can expect to see around five meteors per hour after it gets dark.
RACHEL
Be sure to watch from a dark location where the effects of house and street lights are minimal.
PAUL
You can tell a meteor is a Taurid if it appears to originate from the east. After 3:00 AM, Taurids will appear to originate from nearly overhead.
RACHEL
Don’t let the fact that astronomers expect to see only five meteors per hour from this shower dissuade you from observing it.
PAUL
That’s because the Taurid meteors appear to contain a larger than usual share of large-sized particles.
RACHEL
You have a greater chance of seeing a fireball or bolide during this shower as a result of the larger meteoroids.
PAUL
The 9th would have been Carl Sagan's 79th birthday.
RACHEL
Most Idahoans know Sagan from his efforts to bring science to the public through his books and the PBS program, Cosmos.
PAUL
Sagan’s gift for science popularization is sorely missed.
RACHEL
Fortunately, we still have people like Neil deGrasse Tyson and Bill Nye.
PAUL
That’s Idaho Skies for the first week of November. Next week, Mercury will be visible to Idahoans early in the morning.
RACHEL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.
For Idaho Skies this is Rachel...
PAUL
...and Paul.
RACHEL
Dark skies and bright stars.
Saturday, November 2, 2013
November's star, Alpheratz
The surface temperature of Alpheratz is approximately 23,000 degrees F (making it what astronomers call a class B star). Being 150% hotter than the surface of our sun, Alpheratz produces significantly more ultraviolet radiation than the sun. In addition to producing more ultraviolet radiation, the star is producing 200 times more radiation than our Sun. To emit this amount of radiation, Alpheratz must be more massive than the sun. As a result of this additional mass, mathematical calculations predict that Alpheratz will live a shorter life than the Sun.
Alpheratz is not alone in space. It has a companion star with an orbital period of 97 days. Alpheratz is too distant and its companion too close for telescopes to see the two stars separately. Astronomers determine that stars like Alpheratz are binary stars by measuring the variations occurring in their combined spectra. The lines in the spectra of Alpheratz shift back and forth over a period of 97 days, giving away the fact that there are two orbiting each other in this period of time. We call stars like these spectroscopic binaries because of the way astronomers detect them.
Saturday, October 26, 2013
Transcript for the Last Week of October
RACHEL
Welcome to Idaho Skies for the last week of October. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
On October 30th, 1938, the Mercury Theatre on the Air broadcasted a radio play.
PAUL
The producer was Orson Welles and he based his play on H. G. Wells’ War of the Worlds.
RACHEL
Orson Well’s Martian invasion was occurring that evening in Grover’s Mill, New Jersey.
PAUL
This was on the eve of war in Europe and many Americans found the news out of Europe unsettling.
RACHEL
Some feared that European events would drag the United States into another foreign war.
PAUL
Under this cloud uncertainty, the radio audience listened to news bulletins of strange events out of Grover’s Mill.
RACHEL
The news bulletins breaking into the ongoing music program told of Martian war machines attacking power plants and marching across the Hudson River.
PAUL
The panic that ensued was not as large as some stories have made it out to be.
RACHEL
Today we know Mars is a dead world.
PAUL
However, it may not have always been that way.
RACHEL
That’s right. Evidence collected by spacecraft point to a planet that in its past had large bodies of water.
PAUL
We don’t know yet how long conditions on Mars remained clement; however, it is possible that it was long enough for life to originate.
RACHEL
Any life that exists today is microbial at best.
PAUL
In order to discover it, spacecraft will need to drill deep into the planet’s surface or search through lava tubes.
RACHEL
On November 1st, Venus is at its greatest eastern elongation.
PAUL
The Evening Star will be visible in the west for two hours after it gets dark.
RACHEL
You can observe it sooner if you know where to look for it in the sunlit sky.
PAUL
You will find the planet low in the southwest when the sky gets dark at 7 PM.
RACHEL
Like Mars, some astronomers once considered Venus as potentially habitable.
PAUL
This was before they developed the tools to measure the temperature of Venus from Earth using microwave receivers.
RACHEL
Like Mars, Venus may have once been habitable billions of years ago.
PAUL
That’s before the sun warmed its surface to the point that a run away greenhouse ensued.
RACHEL
Today Venus is a scorching hot world with clouds of sulfuric acid and no water.
PAUL
Finally, this week, don’t forget to set your clock back on Saturday night, the second of November.
RACHEL
It’s the end of daylight saving time, so enjoy your extra hour of sleep.
PAUL
That’s Idaho Skies for the last week of October. Join us next month for the space and astronomical events in Idaho.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for the last week of October. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
On October 30th, 1938, the Mercury Theatre on the Air broadcasted a radio play.
PAUL
The producer was Orson Welles and he based his play on H. G. Wells’ War of the Worlds.
RACHEL
Orson Well’s Martian invasion was occurring that evening in Grover’s Mill, New Jersey.
PAUL
This was on the eve of war in Europe and many Americans found the news out of Europe unsettling.
RACHEL
Some feared that European events would drag the United States into another foreign war.
PAUL
Under this cloud uncertainty, the radio audience listened to news bulletins of strange events out of Grover’s Mill.
RACHEL
The news bulletins breaking into the ongoing music program told of Martian war machines attacking power plants and marching across the Hudson River.
PAUL
The panic that ensued was not as large as some stories have made it out to be.
RACHEL
Today we know Mars is a dead world.
PAUL
However, it may not have always been that way.
RACHEL
That’s right. Evidence collected by spacecraft point to a planet that in its past had large bodies of water.
PAUL
We don’t know yet how long conditions on Mars remained clement; however, it is possible that it was long enough for life to originate.
RACHEL
Any life that exists today is microbial at best.
PAUL
In order to discover it, spacecraft will need to drill deep into the planet’s surface or search through lava tubes.
RACHEL
On November 1st, Venus is at its greatest eastern elongation.
PAUL
The Evening Star will be visible in the west for two hours after it gets dark.
RACHEL
You can observe it sooner if you know where to look for it in the sunlit sky.
PAUL
You will find the planet low in the southwest when the sky gets dark at 7 PM.
RACHEL
Like Mars, some astronomers once considered Venus as potentially habitable.
PAUL
This was before they developed the tools to measure the temperature of Venus from Earth using microwave receivers.
RACHEL
Like Mars, Venus may have once been habitable billions of years ago.
PAUL
That’s before the sun warmed its surface to the point that a run away greenhouse ensued.
RACHEL
Today Venus is a scorching hot world with clouds of sulfuric acid and no water.
PAUL
Finally, this week, don’t forget to set your clock back on Saturday night, the second of November.
RACHEL
It’s the end of daylight saving time, so enjoy your extra hour of sleep.
PAUL
That’s Idaho Skies for the last week of October. Join us next month for the space and astronomical events in Idaho.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Sunday, October 20, 2013
Transcript for the Third Week of October 2013
PAUL
Welcome to Idaho Skies for the fourth week of October. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The moon appears between two star clusters on the evening of the 20th.
RACHEL
You’ll want to get your binoculars out for this astronomical event.
PAUL
After dark on the 20th, you’ll find the Pleiades star cluster left of the moon and the larger, sparser Hyades star cluster below the Pleiades.
RACHEL
You may know the Pleiades star cluster by its popular name, the Seven Sisters.
PAUL
In Greek mythology, the Seven Sisters were the daughters of Atlas, a Titan.
RACHEL
After the war between the Titans and the Zeus, king of the Greek gods, Atlas was forced to carry the heavens on his shoulders.
PAUL
That’s when Orion the Hunter began pursuing seven of his daughters.
RACHEL
This made Atlas most unhappy.
PAUL
Zeus, who cursed Atlas to carry the heavens, took pity on Atlas in this one regard and placed his daughters in the heavens for their protection.
RACHEL
In dark skies, people with good vision can see six stars in the Pleiades.
PAUL
And that it has the shape like a tiny dipper. However, this is not the Little Dipper.
RACHEL
Now look at them in your binoculars and you’ll see at least two dozen stars in the Pleiades.
PAUL
The stars in the Pleiades formed around 100 million years ago.
RACHEL
This was near the end of the reign of the dinosaurs.
PAUL
That means these stars are only two percent of the age of our solar system.
RACHEL
The Orionid meteor shower peaks on the night of October 20th and morning of the 21st.
PAUL
Typically, 21 meteors per hour are visible from this shower.
RACHEL
Unfortunately, the moon is just past full this morning.
PAUL
That means 2013 is not a great year to watch this meteor shower.
RACHEL
Your chances of seeing Orionid meteors occurs several days earlier when the moon sets while it’s still dark.
PAUL
Speaking of the moon, it traverses the outer edge of the Hyades star cluster on the night of the 21st.
RACHEL
In Greek mythology, the Hyades are also daughters of Atlas.
PAUL
Astronomers tell us that the stars in the Hyades are six times older than the neighboring Pleiades.
RACHEL
If you point your binoculars at the moon on the 21st, you’ll see that this star cluster spans an area much larger than the moon.
PAUL
You will also see that it has a distinct V shape.
RACHEL
You will see several dozen stars in this cluster in dark skies.
PAUL
The moon is just below Gemini on the morning of the 26th
RACHEL
To the moon’s left, you will see a very bright star that’s not a part of this constellation.
PAUL
It’s Jupiter and it is so bright that you can’t miss it.
RACHEL
Look at Jupiter through your binoculars and you will see three fainter stars forming a line with the brighter planet.
PAUL
These are its largest moons.
RACHEL
From the bottom-left to the top-right, you will see Callisto, Europa, Jupiter, and finally Io and Ganymede.
PAUL
However, Io and Ganymede are so close together they can’t be resolved as individual satellites.
RACHEL
That’s Idaho Skies for the fourth week of October. Next week we’ll discuss Mars and Venus.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Paul…
RACHEL
and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for the fourth week of October. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
The moon appears between two star clusters on the evening of the 20th.
RACHEL
You’ll want to get your binoculars out for this astronomical event.
PAUL
After dark on the 20th, you’ll find the Pleiades star cluster left of the moon and the larger, sparser Hyades star cluster below the Pleiades.
RACHEL
You may know the Pleiades star cluster by its popular name, the Seven Sisters.
PAUL
In Greek mythology, the Seven Sisters were the daughters of Atlas, a Titan.
RACHEL
After the war between the Titans and the Zeus, king of the Greek gods, Atlas was forced to carry the heavens on his shoulders.
PAUL
That’s when Orion the Hunter began pursuing seven of his daughters.
RACHEL
This made Atlas most unhappy.
PAUL
Zeus, who cursed Atlas to carry the heavens, took pity on Atlas in this one regard and placed his daughters in the heavens for their protection.
RACHEL
In dark skies, people with good vision can see six stars in the Pleiades.
PAUL
And that it has the shape like a tiny dipper. However, this is not the Little Dipper.
RACHEL
Now look at them in your binoculars and you’ll see at least two dozen stars in the Pleiades.
PAUL
The stars in the Pleiades formed around 100 million years ago.
RACHEL
This was near the end of the reign of the dinosaurs.
PAUL
That means these stars are only two percent of the age of our solar system.
RACHEL
The Orionid meteor shower peaks on the night of October 20th and morning of the 21st.
PAUL
Typically, 21 meteors per hour are visible from this shower.
RACHEL
Unfortunately, the moon is just past full this morning.
PAUL
That means 2013 is not a great year to watch this meteor shower.
RACHEL
Your chances of seeing Orionid meteors occurs several days earlier when the moon sets while it’s still dark.
PAUL
Speaking of the moon, it traverses the outer edge of the Hyades star cluster on the night of the 21st.
RACHEL
In Greek mythology, the Hyades are also daughters of Atlas.
PAUL
Astronomers tell us that the stars in the Hyades are six times older than the neighboring Pleiades.
RACHEL
If you point your binoculars at the moon on the 21st, you’ll see that this star cluster spans an area much larger than the moon.
PAUL
You will also see that it has a distinct V shape.
RACHEL
You will see several dozen stars in this cluster in dark skies.
PAUL
The moon is just below Gemini on the morning of the 26th
RACHEL
To the moon’s left, you will see a very bright star that’s not a part of this constellation.
PAUL
It’s Jupiter and it is so bright that you can’t miss it.
RACHEL
Look at Jupiter through your binoculars and you will see three fainter stars forming a line with the brighter planet.
PAUL
These are its largest moons.
RACHEL
From the bottom-left to the top-right, you will see Callisto, Europa, Jupiter, and finally Io and Ganymede.
PAUL
However, Io and Ganymede are so close together they can’t be resolved as individual satellites.
RACHEL
That’s Idaho Skies for the fourth week of October. Next week we’ll discuss Mars and Venus.
PAUL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com For Idaho Skies this is Paul…
RACHEL
and Rachel.
PAUL
Dark skies and bright stars.
Sunday, October 6, 2013
Transcript for 6 to 12 October
PAUL
Welcome to Idaho Skies for the second week of October. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Early on the evening of the 8th, the young crescent moon forms a triangle with two other astronomical objects.
RACHEL
To the lower right of the moon is brilliant Venus.
PAUL
Even though Venus is not the planet closest to the sun, its surface is hotter than Mercury’s.
RACHEL
To the moon’s lower left is the other party in this trio, the star Antares.
PAUL
Antares is a super red giant star and the brightest star of Scorpius the Scorpion.
RACHEL
The trio of the moon, Venus, and Antares will be very low in the southwest at 8:00 PM.
PAUL
Find a location with a clear southwest horizon in order to maximize your viewing time of this alignment.
RACHEL
This is not the end of the action in the low west. Venus and Antares continue approaching closer to each other until next week.
PAUL
So you might want to keep an eye on this region of the sky even after the moon has left the scene.
RACHEL
The moon is passing through a thick section of the Milky Way on the 10th.
PAUL
This area of the Milky Way lies between Earth and the central bulge of the Milky Way galaxy.
RACHEL
Since its closer to the nucleus of the galaxy, it contains more star clusters and nebulae than any other part of the sky.
PAUL
Many of the star clusters and nebulae are visible in a pair of binoculars, if you observe them where the sky is clear and dark.
RACHEL
You’ll need to find a location away from light and let your eyes become adapted to the dark.
PAUL
Did you know that your eyes adapt to the dark by dilating your pupils.
RACHEL
This lets more light enter into your eye and then you can see fainter stars as a result.
PAUL
The process of getting dark adapted can take as long as 20 minutes for older adults.
RACHEL
After your eyes have adapted, begin scanning the region west of the moon with your binoculars.
PAUL
Be sure to scan both high and low.
RACHEL
In binoculars, the stars will remain pin points of light.
PAUL
Nebulae however will appear as hazy spots.
RACHEL
Some of the largest star clusters will appear as small sprinkles of fainter stars.
PAUL
Did you know that it was Galileo who first discovered the nature of the Milky Way?
RACHEL
In 1609, Galileo overheard news about the discovery of a new optical instrument invented in Holland.
PAUL
An ambassador claimed the instrument magnified the view of what ever it was pointed at.
RACHEL
Galileo quickly realized its operating principle and made one for himself.
PAUL
His first telescope only magnified three times.
RACHEL
In time however, he became expert at making lenses and eventually created a telescope capable of magnifying 30 times.
PAUL
So Galileo is not the inventor of the telescope, but he is one of the first to turn it towards the heavens, including the Milky Way.
RACHEL
And he was the first to publish the results so that the public could read about them.
PAUL
Galileo discovered that the nebulous appearing Milky Way became a multitude of stars in his telescope.
RACHEL
You can do the same this week with your binoculars.
PAUL
That’s Idaho Skies for the second week of October. Next week is the Hunter’s Moon.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com. For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for the second week of October. We’re your hosts, Paul…
RACHEL
…and Rachel.
PAUL
Early on the evening of the 8th, the young crescent moon forms a triangle with two other astronomical objects.
RACHEL
To the lower right of the moon is brilliant Venus.
PAUL
Even though Venus is not the planet closest to the sun, its surface is hotter than Mercury’s.
RACHEL
To the moon’s lower left is the other party in this trio, the star Antares.
PAUL
Antares is a super red giant star and the brightest star of Scorpius the Scorpion.
RACHEL
The trio of the moon, Venus, and Antares will be very low in the southwest at 8:00 PM.
PAUL
Find a location with a clear southwest horizon in order to maximize your viewing time of this alignment.
RACHEL
This is not the end of the action in the low west. Venus and Antares continue approaching closer to each other until next week.
PAUL
So you might want to keep an eye on this region of the sky even after the moon has left the scene.
RACHEL
The moon is passing through a thick section of the Milky Way on the 10th.
PAUL
This area of the Milky Way lies between Earth and the central bulge of the Milky Way galaxy.
RACHEL
Since its closer to the nucleus of the galaxy, it contains more star clusters and nebulae than any other part of the sky.
PAUL
Many of the star clusters and nebulae are visible in a pair of binoculars, if you observe them where the sky is clear and dark.
RACHEL
You’ll need to find a location away from light and let your eyes become adapted to the dark.
PAUL
Did you know that your eyes adapt to the dark by dilating your pupils.
RACHEL
This lets more light enter into your eye and then you can see fainter stars as a result.
PAUL
The process of getting dark adapted can take as long as 20 minutes for older adults.
RACHEL
After your eyes have adapted, begin scanning the region west of the moon with your binoculars.
PAUL
Be sure to scan both high and low.
RACHEL
In binoculars, the stars will remain pin points of light.
PAUL
Nebulae however will appear as hazy spots.
RACHEL
Some of the largest star clusters will appear as small sprinkles of fainter stars.
PAUL
Did you know that it was Galileo who first discovered the nature of the Milky Way?
RACHEL
In 1609, Galileo overheard news about the discovery of a new optical instrument invented in Holland.
PAUL
An ambassador claimed the instrument magnified the view of what ever it was pointed at.
RACHEL
Galileo quickly realized its operating principle and made one for himself.
PAUL
His first telescope only magnified three times.
RACHEL
In time however, he became expert at making lenses and eventually created a telescope capable of magnifying 30 times.
PAUL
So Galileo is not the inventor of the telescope, but he is one of the first to turn it towards the heavens, including the Milky Way.
RACHEL
And he was the first to publish the results so that the public could read about them.
PAUL
Galileo discovered that the nebulous appearing Milky Way became a multitude of stars in his telescope.
RACHEL
You can do the same this week with your binoculars.
PAUL
That’s Idaho Skies for the second week of October. Next week is the Hunter’s Moon.
RACHEL
Be sure to read our blog for additional information. It’s at idahoskies dot blogspot dot com. For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Sunday, September 29, 2013
Transcript fior September 29th to October 5th
RACHEL
Welcome to Idaho Skies for the first week of October. We’re your hosts, Rachel…
PAUL
… and Paul.
RACHEL
The very thin crescent moon is located between Regulus, the brightest star of Leo the Lion, and Mars on the 1st.
PAUL
You’ll need to go outside at 6:00 AM to see this alignment.
RACHEL
Regulus, also known as Alpha Leonis to astronomers, is 77 light years away.
PAUL
So if you know someone who is 77 years old this year, Regulus is their birthday star.
RACHEL
Mars is too small and distant to show any detail in binoculars.
PAUL
And the moon will be so thin that binoculars won’t make out much detail on its surface.
RACHEL
Speaking of the moon, did you know the far side of the moon remained a mystery until 54 years ago this month?
PAUL
The Soviet Union placed the spacecraft Luna 3 into a very elliptical orbit.
RACHEL
At its farthest point from Earth, it passed behind the moon.
PAUL
As it passed the moon on October 3, 1959, the 950 pound, solar-powered Luna 3 snapped several poor quality images of the moon’s far side.
RACHEL
This was back in the days of film, so the Luna 3 had to develop the negatives itself.
PAUL
As it passed close to Earth again, Luna 3 scanned the images and transmitted them as a fax.
RACHEL
Remember that the moon has a far side, but not a dark side.
PAUL
That’s right; the far side gets daylight for two weeks per month, so it’s no darker than the near side that we can see.
RACHEL
The reason the moon has a far side is that it is tidally locked.
PAUL
This happens to all small astronomical bodies that are orbiting close to massive astronomical bodies.
RACHEL
It’s happening now to Mercury because of its small distance from the sun.
PAUL
The hot Jupiter exoplanets that astronomers have discovered around other stars are likely tidally locked also.
RACHEL
The moon is new on the 4th.
PAUL
This means the first week of October is a great time for observing faint fuzzy objects through your binoculars or telescope.
RACHEL
Unfortunately, it also means that the moon will be near full at the peak of the Orionid meteor shower.
PAUL
In place of observing meteors, try observing the Zodiacal Light this month.
RACHEL
It appears as a faint glowing pillar of light in the east at least two hours before sunrise.
PAUL
Unlike the dawn, the Zodiacal Light forms a tall triangular-shaped pillar that tilts slightly towards the south.
RACHEL
It’s the reflection of sunlight off of comet dust orbiting the sun.
PAUL
You don’t have to be in a hurry to see the Zodiacal Light; you have until the 17th to see it.
RACHEL
After then, the moon’s light will brighten the sky and interfere.
PAUL
That’s Idaho Skies for the first week of October. Next week the moon passes through the best part of the Milky Way, so get your binoculars ready.
RACHEL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.
For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for the first week of October. We’re your hosts, Rachel…
PAUL
… and Paul.
RACHEL
The very thin crescent moon is located between Regulus, the brightest star of Leo the Lion, and Mars on the 1st.
PAUL
You’ll need to go outside at 6:00 AM to see this alignment.
RACHEL
Regulus, also known as Alpha Leonis to astronomers, is 77 light years away.
PAUL
So if you know someone who is 77 years old this year, Regulus is their birthday star.
RACHEL
Mars is too small and distant to show any detail in binoculars.
PAUL
And the moon will be so thin that binoculars won’t make out much detail on its surface.
RACHEL
Speaking of the moon, did you know the far side of the moon remained a mystery until 54 years ago this month?
PAUL
The Soviet Union placed the spacecraft Luna 3 into a very elliptical orbit.
RACHEL
At its farthest point from Earth, it passed behind the moon.
PAUL
As it passed the moon on October 3, 1959, the 950 pound, solar-powered Luna 3 snapped several poor quality images of the moon’s far side.
RACHEL
This was back in the days of film, so the Luna 3 had to develop the negatives itself.
PAUL
As it passed close to Earth again, Luna 3 scanned the images and transmitted them as a fax.
RACHEL
Remember that the moon has a far side, but not a dark side.
PAUL
That’s right; the far side gets daylight for two weeks per month, so it’s no darker than the near side that we can see.
RACHEL
The reason the moon has a far side is that it is tidally locked.
PAUL
This happens to all small astronomical bodies that are orbiting close to massive astronomical bodies.
RACHEL
It’s happening now to Mercury because of its small distance from the sun.
PAUL
The hot Jupiter exoplanets that astronomers have discovered around other stars are likely tidally locked also.
RACHEL
The moon is new on the 4th.
PAUL
This means the first week of October is a great time for observing faint fuzzy objects through your binoculars or telescope.
RACHEL
Unfortunately, it also means that the moon will be near full at the peak of the Orionid meteor shower.
PAUL
In place of observing meteors, try observing the Zodiacal Light this month.
RACHEL
It appears as a faint glowing pillar of light in the east at least two hours before sunrise.
PAUL
Unlike the dawn, the Zodiacal Light forms a tall triangular-shaped pillar that tilts slightly towards the south.
RACHEL
It’s the reflection of sunlight off of comet dust orbiting the sun.
PAUL
You don’t have to be in a hurry to see the Zodiacal Light; you have until the 17th to see it.
RACHEL
After then, the moon’s light will brighten the sky and interfere.
PAUL
That’s Idaho Skies for the first week of October. Next week the moon passes through the best part of the Milky Way, so get your binoculars ready.
RACHEL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.
For Idaho Skies this is Rachel…
PAUL
and Paul.
RACHEL
Dark skies and bright stars.
Wednesday, September 4, 2013
Deneb is somewhere between 1,600 and 2,600 light years away. This makes Deneb the most distant star visible without a telescope. The reason that we can see it from so far away is that it is a massive star. It has 20 times the mass of the Sun and a diameter 200 times greater than our Sun’s diameter. If Deneb were to replace our Sun, it would fill the orbit of Earth. Deneb’s large mass makes it 250,000 times brighter than the Sun. Deneb has a surface temperature of 16,000 degrees Fahrenheit, or white hot. For Earth to maintain a mild climate while in orbit around Deneb, Earth would have to orbit Deneb at a distance ten times greater than the distance between Pluto and the Sun. The supergiant Deneb is so hot that it is blowing material off of its surface at a rate a thousand times faster than the Sun. This large mass loss is not sufficient, however, to reduce Deneb’s mass down to safe levels before its too late. Within a few million years, Deneb will end its life in a supernova explosion.
Deneb appears directly overhead at 9:30 PM in early September and at 8:30 PM by the end of the month. Look for Deneb as the faintest and most northeast member of the Summer Triangle.
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