Puerto Rico is an island about 1000 miles south of Florida. It is close to the equator so it never gets very cold. When Flat Ally arrived in May it was 90 degrees and the rainy season had just started. We needed to be sure that she didn't get too wet. One thing Flat Ally noticed was that Spanish was the main language in Puerto Rico. Even the cartoons on tv were in Spanish. She decided that she'd brush up on her Spanish a little before heading out to meet the people. I was impressed with how fast she picked it up. After a few days she sounded like a native (which might give her Spanish teacher back in Santa Rosa a fit..).

    The Arecibo Observatory is a radio telescope run by Cornell university for the National Science Foundation. It is the largest single dish radio telescope in the world. It has a main reflector (or dish) sitting in the ground that is 1000 feet across. It covers about 20 acres. This dish is just an oversized version of the tv satellite dishes that you see on the top of some peoples houses. Instead of pointing at satellites that carry tv stations, this radio telescope looks out at the atmosphere, asteroids, planets, stars, and galaxies to learn more about how they work.

    When you look at a star at night, you see the light with your eyes that the star gives off. It turns out that stars also emit radio waves. These radio waves are just like (the same frequencies) as the signals from radio and tv stations (although we haven't picked up Sesame Street from any stars yet..). We don't see these radio waves from the stars just like we don't see the radio waves from tv and radio stations because our eyes are not sensitive to this frequency. But they're still there to be studied.

    After resting up a bit (and gluing Ally to some cardboard do she wouldn't droop) we headed out to explore the Arecibo Observatory. We   got Jose Fernandez (an atmospheric scientist from peru who works at the observatory) to be the official Flat Ally holder.

A little background to help explain the picture tour:

    The observatory has 3 towers each about 250 feet tall. They are called tower 12 (T12), tower 4 (T4), and tower 8 (T8).  They got these names because they have the same relative locations as the numbers on a clock face. T12 is at 12 o'clock and faces north. T4 is at 4 o'clock and faces southeast. T8 is at 8 o'clock and faces southwest.
    The towers have cables that hold up a platform weighing 1.8 million pounds. This platform is suspended 500 feet above a metal reflector or dish that sits above the ground and covers 20 acres. Radio waves from a star or galaxy come down from the sky and bounce off of the 20 acre dish sitting on the ground. They  then get focused by the dish up onto a receiver that is  on the platform. To protect the receivers from the rain and the wind, they are enclosed in a large ball or dome that people call the gregorian dome.
   The tour started at the control room where we took a few pictures. We then headed over to the helipad where we got a better view of the platform, the catwalk  (that lets you walk up to the platform),  and towers 12 and 8. From there is was over to the base of tower 4 for more views of the dish.
    From the base of tower 4 we headed over to the back of tower 8 close to where the anchor cables attached to the ground.  From here we looked out at the bumpy karst region that makes up most of the local terrain. Down at the bottom of the cliff behind anchor 8 we could see the tanama river rushing along.
    After tower 8 we went to  the edge of the dish. The hole in the center of the dish (500 feet away) was our next destination. To get there we took the road that winds down under the dish to the center. We then climbed up on the survey platform so we were standing in the middle of the dish.
    Sitting under the dish we saw all of the cables that are used to pull the dish into the spherical shape that is needed to make the reflector work correctly. We also stopped off at the tiedown blocks where cables went all the way up to the platform. These cables are connected to a  large jack and are used (under computer control) to make sure that the platform does not move up or down when the temperature changes.
    From under the dish we headed over to phil's house (about a mile outside the observatory) where Flat Ally got to meet Betsy.

The picture tour..
   Since phil now has a digital camera there are more than 4 pictures that the other two Flat visits got.. The tour starts here...clicking on the medium sized picture will bring up a larger version.

    More information about the telescope can be found at the Arecibo observatory home page or try  phil's home page .