Idaho Skies Transcript for April 20th, 21st, and 22nd

RACHEL
Welcome to Idaho Skies for April 20th, 21st, and 22nd. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
It’s been a pretty dry season when it comes to meteor showers.

PAUL
In fact, our last one was over three months ago.

RACHEL
So happy news, Earth passes through a dense comet dust trail on the night of the 22nd and morning of the 23rd.

PAUL
That trail was left by Comet Thatcher, which astronomer A.E. Thatcher discovered in 1861.

RACHEL
Comets consist of a snowball of ice and dust, which astronomers call the comet’s nucleus.

PAUL
As the comet’s nucleus approaches the sun, its icy surface warms up and tries to melt.

RACHEL
But since the comet is located in deep space, there’s no air pressure on the nucleus.

PAUL
Which means the ice can’t melt; instead, it sublimates directly into gas rather than melting into a liquid.

RACHEL
The expanding cloud gas surrounding the nucleus is called the comet’s coma.

PAUL
And it’s carrying away rocky material from the comet’s nucleus.

RACHEL
That rocky material spreads out and continues to orbit the sun in the comet’s elongated orbit.

PAUL
And it’s on the 22nd that Earth’s circular orbit intersects the orbit of Comet Thatcher.

RACHEL
The dust from Comet Thatcher slams into the upper atmosphere at a speed of 29 miles per second.

PAUL
Or 146 times faster than the speed of sound.

RACHEL
That rapidly compresses the air ahead of the meteoric dust.

PAUL
And causes the air to get extremely hot and melt the dust.

RACHEL
Which gives rise to the meteor streak we see during a meteor shower.

PAUL
That’s Idaho Skies for the 20th, 21st, and 22nd of April.

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.