Monday, February 28, 2011

Our Planets, and Sun, Compared

8109363Tonight on the Science Channel I’m watching a TV show called “Wonders of the Solar System”. The host is a physics professor named Brian Cox.  I’m fascinated by the topic and I’m drawn to Mr. Cox’s enthusiasm.  Early in the show he showed us a simple science experiment involving a tin can, water, a thermometer and an umbrella.  This experiment shows you that the sun emits roughly a kilowatt of energy upon each square meter of the earth. He then explains that this information can lead to a rational guess at how much energy the sun provides.  He says 400 Million Million Million watts of power. 
As the show progresses he explains that with all the moons that exist in our solar system; Earth is the only one that can experience a solar eclipse. That’s because the sun is 400 times larger than our moon, and also, the sun is 400 times further away from Earth than our moon. 
The previous episode of this show Brian spent a great deal of time discussing the moons and rings of Saturn.  Naming the moons, like Titan as he tells the story of their involvement with Saturn’s rings. Perhaps the thought has hit you before, what is the name of our moon.  So, I go to Google and try to find an answer.  After looking at a few different sites I decided to go to  From there I found this excerpt by Dr. Eric Christian that can be found here:
“The Moon was called Selene or Artemis by the Greeks and Luna by the Romans. I'm sure other cultures also had names for the Moon. But in English, Moon (from Mona and Moone in Old and Middle English) was used before anyone had any idea that the other planets had moons. So it was more a case that the specific name for the Moon was extended to mean small bodies revolving around planets elsewhere. The Moon's name is the Moon.”
By now, my mind has begun to wander and I recall something I was told years ago about the relative size of the sun, and solar system.  If you’re from Pittsburgh you’ll understand this more readily….
If the sun were a 2 story tall yellow ball standing at the base of the Cathedral of Learning (University of Pittsburgh) the earth would be the size of a basketball at center ice of the Mellon Arena (1.93 miles away or 3.11 Km).  The Moon would be the size of a softball resting on the blue line.  The nearest star (Proxima Centauri) would be sitting on top of the moon.  With that story in mind I started googling and I came upon this site.  I really think you ought to SolarSystemcheck this site out. It’s filled with great photos like this one that shows  the relative sizes of planets, then suns that are out there in the universe.  I had no idea how much larger the largest suns were when compared with our own.
I really recommend you take a look. (here).  There’s another picture that shows our sun compared to Sirius, Pollux and Arcturus, three larger suns. 
One last interesting tidbit I learned today.  On Venus, a year is actually less than a day.  If I remember correctly, it takes 260 earth days for Venus to circle the Sun while it takes 280 days for Venus to rotate. 


Post a Comment