WPBT2's Star Gazers

Episode #12-03 "Which Season is the Longest?"
Air Dates January 16- January 22, 2012



FIVE MINUTE EPISODE SCRIPT
JAMES: Welcome to Star Gazers. I'm James Albury, director of the Kika Silva Pla Planetarium in Gainesville, Florida. 

DEAN: And I'm Dean Regas, outreach astronomer from the Cincinnati Observatory 

JAMES: I'll bet that most of you are under the impression that the 4 seasons are equal in length, when in fact none of them are the same number of days and nights long. So which season is the longest and which is the shortest?

DEAN: Well I'd bet most school children would say that summer is the shortest because it seems to just fly by. But is that true or is it simply a matter of human perception? Let's find out.

Stop and drop

JAMES: O.K., now everyone knows that our earth makes one trip around the sun once a year. In fact, astronomically speaking that's exactly what a year is; the amount of time it takes for any planet to make one trip around the sun, and one Earth trip is 365 1/4 earth days long.

DEAN: Now according to Kepler's laws of motion, the closer a planet is to the sun, the faster it will travel. The farther it is from the sun the slower it will travel. So, because our earth's orbit is not a perfect circle, but is a slightly stretched out circle called an ellipse and since our sun is not at the center of this ellipse, our earth actually varies its distance from the sun during the year. When it's closest to the sun, it travels fastest, and when it's farthest, it travels slowest.

JAMES: Now believe it or not, our earth is actually closest to the sun in January and farthest in July. So our earth actually travels faster when it's winter in the Northern Hemisphere and slower during the summer. Let's show you.

DEAN: O.K., on the first day of spring our earth is traveling at a speed of 66,900 miles per hour and is moving farther from the sun and slowing down and thus takes 93 days to go from the first day of spring to the first day of summer, so spring is 93 days long. Then the earth continues to slow down until it is at its farthest point from the sun the first week of July, when it reaches its slowest speed of 65,500 miles per hour.

DEAN: Thereafter, because it's starting to move back closer to the sun, it slowly starts to speed up. Even so, it takes 94 days for our earth to travel from the first day of summer to the first day of fall, which makes summer 94 days long. Then, as it moves closer and closer to the sun it picks up more speed day by day, so that it takes only 90 days to travel from the first day of fall to the first day of winter. Thus, fall is 90 days long.

JAMES: And our earth continues to speed up until it reaches its closest point to the sun the first week of January, zipping along at 67,600 miles per hour, which is 2,200 miles per hour faster than its speed in july. In fact, it takes only 89 days for our earth to go from the first day of winter to the first day of spring.

DEAN: so even though summer feels like the shortest season to any school kid, winter is actually 5 days shorter and is the shortest season of the year for the northern hemisphere. And summer is the longest.

JAMES: shifting gears a bit, let's take a look at venus and jupiter in the evening sky next week. Venus is the brighter of the two bright lights you'll see in the southwestern sky. Jupiter is the higher of the two.  Jupiter and venus will be getting closer every night and will be at their closest in early march.

DEAN: be sure to get out just after sunset next wednesday january 25th and enjoy a super skinny, 3 day old moon down to the right of venus.

JAMES: if the clouds get in your way wednesday night and you can't see the moon and venus,  don't worry because the next night thursday the 26th you'll have a second chance with a four day old moon up and to the right of venus.

DEAN: so happy 'shortest season of the year' and don't miss the moon and venus next week.

BOTH: keep looking up!

 

Episode #12-03 "Which Season is the Longest?"
Air Dates January 16- January 22, 2012



ONE MINUTE EPISODE SCRIPT
JAMES: Have you ever wondered which season is the longest or shortest? Well, I'll bet most school kids would say summer is the shortest because it just flies by. But is that really true???

Stop and drop

DEAN: You see, our earth's orbit is not a perfect circle, but is an ellipse so our earth actually varies its distance from the sun during the year. When it's closer to the sun, it travels faster, when it's farther away it travels slower.

JAMES: And believe it or not, the earth is closest to the sun in winter and travels over 2,200 miles per hour faster than it does in summer. So fast, in fact, that winter, which is 89 days long, is actually 5 days shorter than summer, which is 94 days long, for the northern hemisphere. So summer is the longest season!

DEAN: Next Wednesday the 25th, just after sunset, look into the southwestern sky and be sure to catch Venus and a super skinny moon. And then the next night, Thursday the 26th, they'll do it all again.

BOTH: Keep looking up!

 

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