Transcript for May 10 - 16

RACHEL
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Earth passes through the thickest part of a meteor stream on the 5th.

PAUL
Its debris left behind by the famous Comet Halley.

RACHEL
Astronomers call the meteor shower the Eta Aquarids.

PAUL
Welcome to Idaho Skies for the second week of May. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
The moon is approaching new again on the 14th and 15th.

RACHEL
That means these are good mornings to see the thin crescent moon.

PAUL
Look for the moon in the low east as you drive to work at 6:00 AM.

RACHEL
And make sure you look for earthshine on the moon.

PAUL
The light of earthshine will help fill in the dark right side of the moon.

RACHEL
Use your binoculars and you should be able to make out some lunar details in the faint light.

PAUL
Did you know that astronomers discovered Pluto in 1930?

RACHEL
However, it wasn’t until 1978 that astronomers discovered it had a satellite.

PAUL
Then ten years ago on the 15th, astronomers discovered two additional moons of Pluto.

RACHEL
Astronomers named the moons Nix and Hydra.

PAUL
Is that because of New Horizons?

RACHEL
Yep, the N and H in Nix and Hydra were chosen for the N and H in New Horizons.

PAUL
New Horizons is the American spacecraft rapidly approaching Pluto.

RACHEL
Pluto has never been explored by spacecraft.

PAUL
So the New Horizons is our first chance to see this enigmatic world close up.

RACHEL
That means it’s important that New Horizons doesn’t collide with an unknown moon as its approaches Pluto.

PAUL
Because of its ability to detect faint objects, astronomers used the Hubble Space Telescope to search for potentially threatening moons.

RACHEL
In addition to Nix and Hydra, Hubble has also discovered the moons Styx and Kerberos.

PAUL
How could tiny Pluto have five moons?

RACHEL
Astronomers believe Pluto was struck by a passing object early in its history.

PAUL
The whack was similar to the one Earth suffered over four billion years ago.

RACHEL
The impact with Pluto resulted in a debris field orbiting the tiny body.

PAUL
Over time, some debris collapsed back onto to Pluto and the rest coalesced into five new moons.

RACHEL
The largest was Charon, which is about half the size of Pluto.

PAUL
One danger for New Horizons comes from debris that may not have formed a moon.

RACHEL
That’s right; some of it may have formed a dark ring around Pluto.

PAUL
So now, New Horizons is taking images of the Plutonian system in search of possible new hazards.

RACHEL
Don’t forget to mark your calendars for July 14th.

PAUL
That’s when the New Horizons will make a high speed flyby of Pluto.

RACHEL
By the way, Nix is the Greek goddess of the night...

PAUL
...Hydra is a multi-headed serpent-like monster that Hercules killed...

RACHEL
...Styx is the Greek ferryman of the dead...

PAUL
...and Kerberos is the three-headed dog that guards the entrance to Hades.

RACHEL
That’s Idaho Skies for the second week of May. There are planets to see and next week we’ll tell you how to find them.

PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com. For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.

Transcript for May 3 - 9

RACHEL
Welcome to Idaho Skies for the first week of May. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Earth passes through the thickest part of a meteor stream on the 5th.

PAUL
Its debris left behind by the famous Comet Halley.

RACHEL
Astronomers call the meteor shower the Eta Aquarids.

PAUL
Why Eta Aquarids?

RACHEL
Because where the stream of debris intersects Earth’s orbit appears to be near the star Eta Aquarid.

PAUL
The meteor shower reaches peak performance after midnight.

RACHEL
And in clear dark skies, one can expect to see about ten meteors per hour.

PAUL
While not a specular rate, it’s a substantial improvement over the seven meteors per hour we see between meteor showers.

RACHEL
Now for the bad news.

PAUL
The moon is full on May 3rd.

RACHEL
That means moonlight will strongly interfere with this shower all night.

PAUL
Still, any meteors you observe will tend to be brighter and leave long trails.

RACHEL
Look for Eta Aquarid meteors to originate from the southeast.

PAUL
Everyone’s favorite planet is the bright star located to the lower left of the moon on the morning of the 5th.

RACHEL
You’ll know you’re looking at Saturn because it won’t twinkle like other stars.

PAUL
And because it will have a slight yellow tint.

RACHEL
Saturn doesn’t show any detail in binoculars, but a small telescope or even spotting scope will show its rings.

PAUL
Saturn’s rings are amazing.

RACHEL
They’re only between 30 and 3,000 feet thick

PAUL
And they’re 180,000 miles across.

RACHEL
That means relative to a sheet of paper, Saturn’s rings are 100 times thinner.

PAUL
The reason we see them is because they consist of reflective ice particles.

RACHEL
Look for Saturn’s rings, you only need a telescope with 25 or greater magnification.

PAUL
Mercury reaches its greatest distance from the sun on the evening of the 7th.

RACHEL
And here’s how to find it.

PAUL
Look low in the northwest at 10:00 PM and locate brilliant Venus.

RACHEL
Below and to the right of Venus and closer to the horizon is little Mercury.

PAUL
Don’t confuse the star Aldebaran for Mercury

RACHEL
Aldebaran is located almost directly below Venus and a bit lower than Mercury.

PAUL
That’s Idaho Skies for the first week of May. Next week’s topic is the satellites of Pluto.

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.

Transcript for April 26 to May 2

PAUL
Welcome to Idaho Skies for the last week of April. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Let’s compare two stars that the will moon pass this week.

RACHEL
The first is Regulus.

PAUL
The moon passes just below Regulus on the night of the 27th.

RACHEL
And the second star is Spica.

PAUL
The moon passes just above Spica on the night of May 1st.

RACHEL
Spica appears just a bit brighter than Regulus, but not by much.

PAUL
Astronomers call Regulus and Spica B class stars.

RACHEL
This is the second highest class and therefore second hottest category of stars.

PAUL
Both appear as blue-white stars because of their exceeding high surface temperatures.

RACHEL
And we mean hot, these stars have surface temperatures twice as high as the sun.

PAUL
Cooler stars like the sun generate energy by fusing hydrogen straight into helium.

RACHEL
However, hotter B class stars use carbon and oxygen as a catalyst to fuse their hydrogen into helium.

PAUL
This hotter fusion process is possible because these stars are much more massive than the sun.

RACHEL
Regulus is four times more massive and Spica is ten times more massive.

PAUL
That extra mass and increased fusion rate makes Regulus nearly 300 times brighter than the sun.

RACHEL
And it makes Spica over 10,000 times brighter.

PAUL
The reason Regulus looks nearly equal to much brighter Spica is that Spica is three times farther away from Earth than Regulus.

RACHEL
After you find Spica below the moon on the 1st, turn your attention to a location below and to the right of Spica.

PAUL
You’re looking for a squashed square of four stars.

RACHEL
These stars are a constellation called Corvus.

PAUL
Corvus is a Crow.

RACHEL
It was one of the original 48 constellations described by Ptolemy back in the second century AD.

PAUL
And it’s one of the smallest of the official 88 astronomical constellations.

RACHEL
So how did a crow become a constellation?

PAUL
According one legend, the Greek god Apollo threw a crow into the heavens after it made him angry.

RACHEL
How does a crow make a god angry?

PAUL
By being late returning a cup of water as asked.

RACHEL
In a fit of rage, Apollo threw Corvus and the cup into the heavens.

PAUL
And let that be a lesson for us all.

RACHEL
That’s Idaho Skies for the last week of April. Join us next month for the space and astronomy events for Idaho.

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

For Idaho Skies this is Paul...

RACHEL
...and Rachel.

PAUL
Dark skies and bright stars.

Transcript for April 19 to 25

RACHEL
Welcome to Idaho Skies for the fourth week of April. We’re your hosts, Rachel... 

PAUL
 ...and Paul.

 RACHEL
Like all stars, Aldebaran, the alpha star of Taurus the Bull is moving closer to the western horizon every night. 

PAUL
Since Venus is a planet, it’s moving away from the horizon every night.

RACHEL
That is at least until June when Venus begins passing between Earth and the sun.

PAUL
Therefore, it’s not surprising to hear that these two celestial objects cross paths on occasion. 

RACHEL
You’ll find Venus on the outskirts of the Hyades star cluster and therefore close to Aldebaran on the evening of the 20th.

PAUL
When you go out to see them, be sure to look for the young and very thin crescent moon close to the horizon.

RACHEL
Two days later, Aldebaran, the moon, the Pleiades, and Venus form a compact grouping.

PAUL
The grouping is so small that you can just about cover them with your outstretched hand on the 21st. 

RACHEL
That’s a bunch of binocular objects for the choosing and you don’t have to scan the rest of the sky to see them.

PAUL
Mercury has traveled its greatest distance away from the sun and is now inching its way back. 

RACHEL
Before long, it will be too close to the horizon and sun to be visible in the evening.

PAUL
On its way back to the sun, the innermost planet passes close to Mars on the 22nd.

RACHEL
Mercury is brighter than Mercury, so you can’t confuse them.

PAUL
At 8:30 PM on the 22nd, scan the sky close to the horizon and to the lower right of Venus.

RACHEL
The first star you’ll find is Mercury.

PAUL
Mars will be the fainter star located to the lower left of Mercury.

RACHEL
It’s been three months since we’ve had the opportunity to watch a meteor shower and quite frankly, we’re overdue.

PAUL
During the last week of April, the Lyrid meteor shower picks up its level of activity.

RACHEL The meteor shower reaches its peak activity on the night of the 22nd and morning of the 23rd.

PAUL
Meteors from this shower will appear to originate from the northeast and become more numerous after midnight.

RACHEL
Fortunately, this year the moon is a thin crescent on the 22nd and it therefore sets before midnight. 

PAUL
On the down side, this is not one of the best meteor showers of the year.

RACHEL
You can only expect to see some ten meteors per hour from this shower.

PAUL
But hey, since our last meteor shower occurred in January, the Lyrids aren’t bad.

RACHEL
The Beehive star cluster is one of the nicest star clusters for binocular viewing.

PAUL
This star cluster is easy to see, but it’s located in a rather blank part of the sky.

RACHEL
So it’s really helpful to have the moon show you its location.

PAUL
On the 25th, scan straight up along the moon’s terminator or the boundary between lunar day and night, until you run into the cluster.

RACHEL
The star cluster will look like a sprinkling of diamond dust in your binoculars.

PAUL There’s another, smaller star cluster nearby called M-67.

RACHEL
And you’ll be able to find this star cluster by keeping in mind that Jupiter, M-67, the moon, and the Beehive star cluster form a square.

PAUL
That’s Idaho Skies for the fourth week of April. Next week we’ll compare two blue-white stars that the moon passes.

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.

Transcript for April 12 - 18

RACHEL Welcome to Idaho Skies for the third week of April. We’re your hosts, Rachel... PAUL ...and Paul. RACHEL The first human to travel into space did so on April 12th, 1961. PAUL His name was Yuri Gagarin and he was a 27 year old pilot of the Soviet Air Force. RACHEL This came as a bit of a surprise to the United States, which was planning to launch American astronauts during Project Mercury. PAUL In fact, if it hadn’t been for concerns about earlier Redstone tests and bad weather, we might have beaten the Soviets and put the first man into space. RACHEL However, Yuri’s flight was significantly different from the first two American flights. PAUL That’s because Yuri actually made one orbit around Earth before returning in his Vostok space capsule. RACHEL The United States launched its first two astronauts using converted Redstone missiles. PAUL And these missiles didn’t have the power to place a Mercury space capsule into orbit. RACHEL That’s why the first two American astronauts were only lobbed 115 miles up before descending back to the Atlantic Ocean. PAUL The reason the Soviets were able to put Yuri into orbit is that their R-7 missile was much larger and powerful than the Redstone. RACHEL Because of concerns they might fail, the Soviets didn’t announce Yuri’s mission until 52 minutes into his flight. PAUL And less than 40 minutes later, he had fired his retro rockets and was returning back to Earth. RACHEL The Mercury capsules returned to Earth by splashing down into the ocean, however the Vostok 1 landed on the ground. PAUL This made for a much harder landing. RACHEL In order to protect their cosmonaut, Yuri was ejected out of the capsule as it neared the ground. PAUL That allowed Yuri to land softly on his own parachute and separate from his capsule. RACHEL Because of his propaganda importance to the Soviet Union, Yuri was never allowed to travel back into space. PAUL The moon takes it time approaching the eastern horizon starting on the 14th. RACHEL That’s because its approach to the sun is very shallow. PAUL This always happens during the spring. RACHEL Contrast this to the autumn when the moon’s approach to the horizon more vertical. PAUL So as a consequence, you have more opportunities to observe Earthshine during spring mornings. RACHEL Look for the moon in the low east-southeast as you drive to work. PAUL Earthshine will appear on the right side of the moon. RACHEL That’s Idaho Skies for the third week of April. Next week marks the end of our drought of meteor showers. PAUL Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com. For Idaho Skies this is Paul... RACHEL ...and Rachel. PAUL Dark skies and bright stars.

Merak is this Month's Star

This month look for the star Merak in Ursa Major. The popular name of Ursa Major is the Big Dipper. Actually, the Big Dipper is an asterism, or familiar pattern of stars and not a constellation. The Big Dipper asterism represents a bear’s hind quarters and extremely long tail. The rest of the bear consists of fainter stars, which gives Ursa Major its ursine shape. The constellation’s name means Great Bear in Latin.

Astronomers call Merak Beta Ursae Majoris. In Arabic, Merak means “flank of the bear”. Merak is a star larger star than our sun; it’s three times more massive and 60 times brighter. Its extra mass squeezes the star’s core with such great force that it’s fusing its hydrogen fuel faster than does the sun. Merak’s greater fusion rate makes it a white hot star with a surface temperature of over 15,000 degrees. Merak is 79 light years away, so the light you see tonight left the star in 1936.

You’ll find Merak and Ursa Major high overhead after it gets dark in April. The dipper is upside down and appears to be pouring the water in its bowl into the Little Dipper.

Transcript for April 5 - 11

PAUL
Welcome to Idaho Skies for the second week of April. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
Looking for Saturn?

RACHEL
Then look no further than the moon on the morning of the 8th.

PAUL
Saturn is the cream-colored star below the moon.

RACHEL
Saturn shows its rings through a small telescope or spotting scope.

PAUL
But not in most binoculars.

RACHEL
A magnification of as little as 25 power is enough to see its rings and brightest satellite, Titan.

PAUL
In a telescope, Titan will appear as the star to the upper right of Saturn.

RACHEL
Titan is a wonderful satellite by itself.

PAUL
It’s 50% larger than Earth’s moon.

RACHEL
And it has an atmosphere 50% greater than Earth’s atmosphere.

PAUL
Below its icy surface may be a deep liquid ocean.

RACHEL
Jupiter is approaching the Beehive star cluster because it’s retrograding.

PAUL
Retrograding? What’s that, some kind of 70’s fashion?

RACHEL
Retrograde motion occurs when Earth’s motion begins to overtake the orbital motion of a more distant planet like Jupiter.

PAUL
So during retrograde, outer planets travel from east to west across the sky, rather then the normal west to east.

RACHEL
On the evening of the 8th, Jupiter reaches the end of its retrograde motion and is at its closest to the Beehive star cluster.

PAUL
The pair is so close together that you can see both at the same time in binoculars.

RACHEL
If you point your binoculars at Jupiter on the 8th, place it on the left edge of your binocular’s view.

PAUL
That way the Beehive star cluster will pop out on the right side.

RACHEL
Then take a closer look at Jupiter to see largest satellite, Ganymede on the right side of Jupiter.

PAUL
When you see Ganymede, you’re looking at the largest satellite in the solar system.

RACHEL
It’s a giant moon that’s larger than the planet Mercury.

PAUL
And as the Hubble Space Telescope recently discovered, it most likely contains a vast ocean beneath its icy exterior.

RACHEL
In fact, there may be more liquid water beneath Ganymede than on Earth.

PAUL
Venus is climbing higher above the horizon every night while the Pleiades star cluster is descending lower.

RACHEL
The two meet up on the evenings of the 10th and 11th when they will be less than three degrees apart

PAUL
That puts them so close together that you can enjoy both at the same time in a pair of binoculars.

RACHEL
The Pleiades are located to the upper right of Venus.

PAUL
Look for the pair in the low west at around 9:30 PM.

RACHEL
You won’t be able to miss brilliant Venus.

PAUL
That’s Idaho Skies for the second week of April. Next week we celebrate a space-age anniversary that took place 54 years ago.

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.