Wednesday, July 1, 2015

Pluto Approaching

The New Horizons spacecraft flies past Pluto on the 14th. Already the spacecraft is giving us better views of Pluto than are possible with the Hubble Space Telescope. And the images are only going to get better!

Be sure to visit the New Horizons website for the latest images and data. For example, New Horizons has already detected methane on Pluto.

 http://pluto.jhuapl.edu/

Transcript for July 26 - August 1

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

RACHEL
...and Rachel.

PAUL
You can find star clusters and nebulae close to the moon on the evening of the 28th.

RACHEL
To see them, scan the region to the moon’s left with your binoculars.

PAUL
Then continue scanning further below.

RACHEL
You’ll see small fuzzy clouds of glowing gas and small sprinkles of stars.

PAUL
The nebulae are clouds of dust and gas glowing from the ultraviolet radiation of recently born stars.

RACHEL
Why are there so many clusters and nebulae in this region of the sky?

PAUL
That’s because this is closer to the center of the Milky Way galaxy.

RACHEL
Stars, including nebulae become concentrated as you approach the center of any galaxy.

PAUL
Summer is meteor shower time.

RACHEL
The shower this week is the Delta Aquarids and they peak on the evening of the 28th and morning of the 29th.

PAUL
Unfortunately, the moon is nearly full that evening.

RACHEL
That means that its light will brighten the night time sky and wash out many of the fainter meteors.

PAUL
However, if you observe a meteor originating from the low south, then it may be a Delta Aquarid meteor.

RACHEL
But have no fear, the best summer meteor shower is yet to come.

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

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.

Transcript for July 19 - 25

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

PAUL
...and Paul.

RACHEL
The moon’s path across the sky in July is very shallow.

PAUL
So the moon never appears very high above the horizon during summer nights.

RACHEL
That means we have to wait until the 20th before the moon gets high enough above the horizon to show Earthshine clearly.

PAUL
The bad news is that the moon will be almost five days old and Earthshine will therefore be weak.

RACHEL
In winter, the situation is reversed.

PAUL
That’s because the moon rises nearly vertically above the horizon.

RACHEL
And it travels higher above the horizon.

PAUL
So we get a clearer view of the moon when it’s younger and thinner.

RACHEL
A young and thin moon is fainter and so it doesn’t wash out the illumination of Earthshine.

PAUL
The moon appears near a bright, but lonely star on the evening of the 22nd.

RACHEL
The star is Spica and it’s the brightest star of Virgo the Maiden.

PAUL
Spica is a white star, indicating that it’s much hotter than our yellow sun.

RACHEL
Spica isn’t the only interesting star the moon passes this week.

PAUL
The next one is Zubenelgenubi.

RACHEL
Zubenelgenubi is a star that’s easy to split into a pair of stars using binoculars.

PAUL
You’ll see the star to the moon’s lower left on the night of the 24th.

RACHEL
Some people with excellent vision can see Zubenelgenubi as a double star without using binoculars.

PAUL
Are you one of those people?

RACHEL
Looking for Saturn?

PAUL
Then wait no later than the 25th when the moon parks next to the ringed jewel of our solar system.

RACHEL
Saturn will be the yellow-white star to the moon’s left that night.

PAUL
One way you’ll know that its Saturn is that it will hardly twinkle, if at all.

RACHEL
Stars twinkle because they have such small apparent disks.

PAUL
That lets individual warm and cold air pockets constantly pass between then and our eyes.

RACHEL
The changing density of these air pockets acts like shaky lens and prisms that bend and refract starlight many times per second.

PAUL
The result is twinkling stars that throw off shards of color.

RACHEL
Saturn on the other hand is thousands of times larger in apparent diameter than the more distant stars.

PAUL
And as a result, unless the air is very turbulent, there are many pockets of air moving over Saturn simultaneously.

RACHEL
Their effects average out leaving Saturn with a nearly constant brightness and color.

PAUL
That’s Idaho Skies for the third week of July. Next week the moon will help you find star clusters and nebulae with your binoculars. 

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 July 12 - 18

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

RACHEL
...and Rachel.

PAUL
On the morning of the 12th, you’ll see the moon slowly passing through the edge of the Hyades star cluster.

RACHEL
This will be an attractive sight through your binoculars.

PAUL
One reason why is that the moon will appear a very thin crescent.

RACHEL
A small telescope will show craters along the illuminated edge of the moon turned nearly edge on from Earth’s perspective.

PAUL
Therefore, they’ll distinctly oval in shape.

RACHEL
If you watch the edge of the moon relative to nearby stars over several minutes, you should be able to detect its movement through the star cluster.

PAUL
Just as it’s finally getting dark a little after 10:00 PM on the 14th, you can see Venus side by side with the brightest star of Leo the Lion.

RACHEL
The star’s name is Regulus, which means prince or little king in Latin.

PAUL
Regulus will be the left of Venus and the much fainter of the pair.

RACHEL
Venus will appear white while Regulus will have a yellowish tint.

PAUL
And that tint may be darker because of the filtering effect of the denser atmosphere near the horizon.

RACHEL
The moon forms a neat line with Jupiter and Venus on the evening of the 18th.

PAUL
Venus and the three day old moon will fit together within the field of view of your binoculars.

RACHEL
Unfortunately, Jupiter will be a little too far away to see all three at the same time in binoculars.

PAUL
Don’t wait much later than 10:00 PM to see them because the trio sets around 10:30.

RACHEL
That’s Idaho Skies for the second week of July. Next week listeners with telescopes can find Saturn and see its rings. 

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 July 5 - 12

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

PAUL
...and Paul.

RACHEL
On the morning of the 11th, the waning crescent moon will help you locate two nice star clusters.

PAUL
You’ll need to stay up late or wake up early, however.

RACHEL
At 4:30 AM, look to the east and you’ll find the Pleiades star cluster just left of the moon.

PAUL
You may be more familiar with the Pleiades’ other name, the Seven Sisters.

RACHEL
With just their eyes, most people can see six of the stars forming this star cluster.

PAUL
And by using binoculars, you’ll see at least 20 of its stellar members.

RACHEL
The cluster has a definite dipper shape and some people mistake it for the Little Dipper.

PAUL
However its’ not.

RACHEL
The Little Dipper is a constellation and not a star cluster.

PAUL
Besides, the Little Dipper is located in the northern sky.

RACHEL
Below the Pleiades is the second cluster.

PAUL
It’s called the Hyades star cluster.

RACHEL
This star cluster is larger than the Pleiades and has an overall "V" shape.

PAUL
And at one end of the V is the yellow-orange star Aldebaran.

RACHEL
However, Aldebaran is much closer to our solar system and not actually a member of the star cluster.

PAUL
That’s Idaho Skies for the first week of July. Next week the moon, Venus, and Jupiter form a neat line in the western sky.

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.

July's Star

This month look for the star Gemma in Corona Borealis. Corona Borealis is Latin for Northern Crown and is a crescent shaped pattern of seven stars located on the back of the constellation Bootes. In Greek mythology, Corona Borealis is the crown given to the mortal Ariadne by the Greek god Dionysus on their wedding night. After his wife died of old age, Dionysus placed the crown in the heavens as a symbol of his eternal love for Ariadne.
 
Gemma is a bright white star. Gemma is 2.7 times heavier than our sun. Its greater mass makes it almost twice as hot as the sun, 67 times brighter, and about three times larger. However, it’s not one of the brightest stars in our sky on account of its distance of 75 light years (you would need binoculars to see the sun 75 light years away). If you know someone who was born in 1940, then Gemma is his or her birthday star this year.

Look for Gemma nearly overhead in the west-northwest after dark. To find it, follow the handle of the Big Dipper to the bright yellow-orange star, Arcturus high in the west. Corona Borealis is located almost straight up from Arcturus.

Monday, June 8, 2015

Transcript for June 28th to July 4th

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

PAUL
...and Paul.

RACHEL
Saturn appears to the moon’s lower right after dark on the 28th.

PAUL
Saturn is not a particularly bright planet, but it sure is attractive through a small telescope.

RACHEL
You can see the planet’s rings if you have a small telescope or even a good spotting scope.

PAUL
Use a magnification of at least 25 power.

RACHEL
Saturn is located close to the constellation of Scorpius the Scorpion this summer.

PAUL
The rest of the constellation is located to the left of Saturn.

RACHEL
Its brightest star is Antares and it’s the orangish star located to the lower left of the moon.

PAUL
Did you know that Antares is over 9,000 times larger than Saturn is?

RACHEL
Even though they both appear star-like to our eyes.

PAUL
Two bright stellar beacons, Jupiter and Venus, appear very close together after sunset on the 29th.

RACHEL
They’re only ½ of a degree apart.

PAUL
Which is also the apparent diameter of the moon.

RACHEL
Get a look at Jupiter and Venus soon because they’ll be too close to the sun in another two or three weeks.

PAUL
The moon has neighbors late on the night of the 30th and morning of July 1st.

RACHEL
Its neighbors are star clusters and nebulae and you can see them through binoculars.

PAUL
Scan the region to the moon’s left, both higher and lower, for fuzzy patches and small star clusters.

RACHEL
Hey, I see a teapot of stars when I star gaze this region without binoculars.

PAUL
That’s right. The teapot-shaped pattern of stars is a part of the constellation of Sagittarius the Archer.

RACHEL
Sagittarius represents the centaur Chiron

PAUL
Chiron was not a violent centaur like the others mentioned in Greek mythology.

RACHEL
He was also known as a good archer, which is how he is represented in the night sky

PAUL
So why is Chiron commemorated in the sky?

RACHEL
That’s because he took the place of Prometheus, who Zeus was punishing for giving fire to humanity.

PAUL
Chiron offered to take the place of suffering Prometheus because a poisoned arrow had injured him.

RACHEL
Since Chiron was immortal and couldn’t die, the wound caused him endless agony with no hope for an end to that suffering.

PAUL
So Zeus, the king of the Greek gods, placed him in to the heavens to honor his sacrifice.

RACHEL
That’s Idaho Skies for the last week of June. 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.