Idaho Skies Transcript for April 3rd and 4th

RACHEL
Welcome to Idaho Skies for April 3rd and 4th. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
Don’t miss the Morning Star this week.

PAUL
Venus is that bright star that stargazers notice in the low east-southeast before sunrise. In fact, 6:00 AM is a good time to observe it. Due to Earth’s movement around the sun, Venus will remain visible during the mornings until July. Its position will change, but primarily along the horizon and not vertically. So compare its position to features on the horizon if you want to notice the planet’s motion.

RACHEL
Until the mid-20th century, Venus was a big unknown. Astronomers could see that the clouds covered the planet, and it had a diameter slightly smaller than Earth’s. Astronomers wondered what was under the clouds, however. No astronomer could ever see an opening though them, so the planet’s surface conditions remained a mystery.

PAUL
Radio telescopes made the first important discovery about Venus. Radio telescopes pointed at the planet discovered that it emitted radiation in the microwave range. This was useful data because all objects emit radiation based on their temperature. Astronomers knew that the hotter an object, the higher the frequency of its peak radiation emission.

RACHEL
What did this detection of microwave radiation indicate? Astronomers determined that the surface of Venus must have a temperature of around 600 degrees Fahrenheit. Carl Sagan used this result to argue that Venus had to have a high pressure atmosphere rich in carbon dioxide. In other words, Venus was suffering from a severe case of greenhouse gas.
   
PAUL
That’s Idaho Skies for the 3rd and 4th 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.