Tonight the Moon is Full, By Jove!


By Jupiter! What a resplendent  full moon  last night!  And that star to the moon's right  is really  none other than that ravishing king of our solar system, Jupiter.

In his orchestral suite, "The Planets"  Gustav Holst labeled Jupiter  'The Bringer of Jollity'.   A good excuse to be jovial tonight too.

Besides being the giant star of  our humble family  in  the Milky Way, Jupiter has many other astonishing aspects.  It takes about a dozen Earth years to make one revolution around the Sun, Jupiter's orbit.  It has 67 moons, although only 4 of any appreciable  size: Io, Europa, Ganymede, and Callisto.  Three of whom the randy Roman supreme god  [his Greek name was Zeus] seduced as described in mythology.

Jupiter is one of the so-called Jovian planets.  Those composed mostly of gas, having no rocks and almost no solid matter.  Saturn, Neptune, and Uranus are the others in the group.  90% of Jupiter is hydrogen, the most basic element in the universe.  Almost 10% of the rest is helium, the second most basic.  There are traces of methane, ammonia, and ethane.  Surprisingly, water too. But only .ooo4%.

It has the largest atmosphere of any planet in our solar system.  It stretches for 5000 kilometers, or about 3125 miles!

Jupiter is truly astronomical.  It is 1/1000 the mass of the Sun.  It is the only planet to have its gravitational center vis a vis the Sun outside the  Sun itself; at a distance of 1/10 the radius of the Sun.

It is about 318 times as massive as the Earth.  And it would take 1321 Earths to fill Jupiter's volume.  It  also has a magnetic field 14 times as strong as  ours.

Something else about Jupiter should give my fellow Earthlings who like astrology pause.  Jupiter may be responsible for the zodiac signs you're born under.  Jupiter's 12-year orbit  which corresponds to the dozen astrological signs may have been the historical origin of those signs.  Each time Jupiter reaches opposition[opposite the Earth from the Sun], it has advanced eastward by about 30 degrees, the width of a zodiac sign.

In ancient India, Jupiter was Brihaspati, religious teacher of the gods.  Hindu astrologers often called it  'Guru':  the Heavy One.

Tonight be sure then to look  skyward and enjoy the full moon. I always do.  But especially tonight with the 4th brightest object in the night nearby, Jupiter.  After all, Thursday was named after Thor, Jupiter's counterpart in Norse mythology. It's a perfect alignment.



Filed under: nature, science

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