Idaho Skies Transcript for September 19th and 20th

PAUL
Welcome to Idaho Skies for September 19th and 20th. We’re your hosts, Paul…

RACHEL
…and Rachel.

PAUL
Mars reached opposition earlier this summer.

RACHEL
Which means it was at its closest to Earth.

PAUL
That closeness also means Mars appeared at its largest and brightest.

RACHEL
For Mars, a planet only half the diameter of Earth, appearing larger than normal isn’t a lot of help for binoculars.

PAUL
But it was significantly brighter.

RACHEL
And in fact, still is.

PAUL
The waning gibbous moon passes just above Mars on the 19th.

RACHEL
You can’t miss the planet with its bright with a distinct yellowish-orange color.

PAUL
Even though Mars was named after various gods of war, its color doesn’t come blood.

RACHEL
Its color comes from iron oxide.

PAUL
Yep, the surface of Mars is rusty.

RACHEL
Over eons, the wind has broken down the rust into a very fine dust.

PAUL
So fine in fact that the weak winds of Mars can loft the dust into the sky.

RACHEL
Which gives Mars an orangish-colored sky.

PAUL
Without that dust, the sky would be black.

RACHEL
That’s because there isn’t enough air in the Martian atmosphere to scatter the sun’s blue light.

PAUL
Earth, on the other hand, as an atmosphere with plenty of oxygen and nitrogen molecules.

RACHEL
And these scatter blue light very strongly.

PAUL
So no matter which way you look up, you see blue light from the sun.

RACHEL
That’s Idaho Skies for the 19th and 20th of September.

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.