Idaho Skies Transcript for February 17th, 18th, and 19th

RACHEL
Welcome to Idaho Skies for February 17th, 18th, 19th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The moon’s at the last quarter phase on the 18th.

PAUL
That means anytime after midnight will be a good time to go moon viewing with your binoculars.

RACHEL
Along the terminator will be a multitude of visible craters.

PAUL
Especially in the southern hemisphere.

RACHEL
Results from Apollo show that moon appears to be made from the mantle of Earth.

PAUL
Which is a metal-poor mix of rocks and minerals.

RACHEL
The similarity is responsible for the hypothesis that the moon formed when a Mars-sized body crashed into the early Earth.

PAUL
People like calling this the Big Whack, but it’s more formally called the Giant-Impact Hypothesis.

RACHEL
The hypothesis was developed in the mid 1970s.

PAUL
And initially, many scientists where not happy with the hypothesis.

RACHEL
That’s because science doesn’t like explanations that require one-time catastrophes.

PAUL
Eventually, data, including computer modeling demonstrated that the explanation wasn’t as ad hoc as believed and actually quite reasonable.

RACHEL
And today, scientists are quite happy to use the explanation to explain the properties of Pluto’s largest satellite, Charon.

PAUL
And also for many satellites detected orbiting asteroids.

RACHEL
The early solar system was a chaotic and dangerous place.

PAUL
That’s Idaho Skies for the 17th, 18th, and 19th of February.

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.