Transcript: December Week 3

PAUL
Welcome to Idaho Skies on Radio Boise. This is the third week of December. We’re your hosts, Paul..

RACHEL
..Rachel..

KRIS
..And Kris

PAUL
Last week was Tycho Brahe’s 460th birthday.

RACHEL
He’s best known for his measurements of the planets’ positions.

KRIS
When Tycho was a young man, predictions of some astronomical events were very poor. For example, the close alignment between two planets could be in error by several days.

PAUL
Tycho wasn’t happy with this amount of inaccuracy in astronomy.

RACHEL
So he decided he had to build his own instruments and an observatory.

KRIS
The observatory was built on land given to Tycho by Emperor Rudolph the second and named Uraniburg. Uraniburg means castle to the stars.

RACHEL
Tycho’s work was exacting. He constantly recalibrated his instruments and took multiple measurements of each planet’s position in the sky.

KRIS
His measurements were amazingly accurate. Especially when you consider they were made shortly before the invention of the telescope.

RACHEL
Tycho hoped his measurements would ultimately settle the argument over the structure of the universe.

PAUL
Today we would say he wanted to determine the structure of the solar system, but most 16th century astronomers would not have understood the term, solar system.

KRIS
To them, the earth at the center of the universe and everything else orbited around it.

RACHEL
But Tycho believed in a modified version of the geocentric universe that we call the Tychoian System.

KRIS
Tycho believed that the planets orbited the sun, but that the sun orbited the earth.

RACHEL
Remember, to most 16th century astronomers, the earth was not a planet.

KRIS
Tycho was a supreme observational astronomer. But he wasn’t a good enough theorist or mathematician to make sense of his observations.

RACHEL
Tycho needed help and in 1600, he hired just the person he needed.

KRIS
And by coincidence, Kepler celebrates his birthday next week. And next week we’ll have more to say about Kepler.

PAUL
The 21st is the 40th anniversary of the launch of Luna 13.

RACHEL
Luna 13 was another Soviet lunar lander.

PAUL
It flew to the moon on top of a nearly two ton crasher stage.

KRIS
The crasher stage fired its engines to slow Luna 13 down in preparation for landing. The spherical lander was ejected shortly before it crashed on the moon.

RACHEL
Luna 13 hit the lunar surface and rolled to a stop.

KRIS
Then the two foot diameter capsule opened the four petals covering its top and began transmitting images and testing the lunar soil.

PAUL
The winter solstice begins on Dec 21 at 6:22 PM.

RACHEL
That marks the beginning of winter in the northern hemisphere.

KRIS
The first day of winter is the shortest day and the longest night of the year.

RACHEL
If you were to watch the sun set for an entire year you would notice its position on the horizon changes every day.

KRIS
The sunset position drifts to the south every day from the beginning of summer to the beginning of winter.

RACHEL
On the winter solstice the sun’s southward movement comes to a stop. And for a few days, the sun appears to set in the same location.

KRIS
The word solstice means, sun standing still. That’s an appropriate description for what happens at the solstices.

RACHEL
And that’s Idaho Skies for the third week of December. Listen next week as we talk about the moon’s orbit and Johannes Kepler.

For Idaho Skies this is Rachel...

PAUL
..Paul..

KRIS
.. and Kris.