Idaho Skies Transcript for July 13-19

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

RACHEL
...and Rachel.

PAUL
Idaho has several opportunities to see the innermost planet this week.

RACHEL
The best morning is the 16th.

PAUL
To find Mercury, you’ll first need to find the Morning Star.

RACHEL
That’s Venus and it appears in the low northeast at 5:15 AM.

PAUL
Look below and left of Venus for a fainter star.

RACHEL
That will be Mercury.

PAUL
Mercury will be easy to find if you have a clear horizon.

RACHEL
Unfortunately, Mercury doesn’t climb very high above the horizon this month.

PAUL
Do you know how Mercury got its name?

RACHEL
It got its name because it travels very quickly around the sun.

PAUL
The Greeks and Romans thought it had the speed and mobility of the Roman god, Mercury.

RACHEL
Did you know that a year on Mercury lasts only 88 Earth days?

PAUL
However, from our perspective on the moving Earth, it appears Mercury’s year lasts 116 days.

RACHEL
Still, that’s shorter than any other planet.

PAUL
So Mercury really does deserve its name.

RACHEL
The moon is located just below Aries the Ram on the morning of the 19th.

PAUL
To locate Aries, follow the terminator of the moon northward.

RACHEL
In a short distance, this path will take you to a flat triangle of three stars.

PAUL
Those three stars form Aries.

RACHEL
Astronomers call the brightest star of Aries, Alpha Arietis.

PAUL
But you can call it Hamal.

RACHEL
Hamal is just about 50 light years away.

PAUL
This means that if you were born in 1964, then Hamal is your birthday star this year.

RACHEL
The fact that we can see Hamal 50 light years away means that it’s much brighter than the sun.

PAUL
At a distance of 50 light years, the sun would be invisible except in a telescope.

RACHEL
Hamal is an orange star, which indicates its cooler than our sun.

PAUL
However, since it’s brighter than the sun overall, its must be a giant star.

RACHEL
In fact, astronomers have determined that Hamal is about 15 times larger than the sun.

PAUL
That’s Idaho Skies for the second week of July. We celebrate two American planetary landings next week.

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.