Ganymede, Moon and Myth--the Sexiest Man in the World

The four moons that Galileo saw when he pointed his telescope at Jupiter are now known as the "Galilean satellites". There are actually seven moons of Jupiter; Galileo could only see four of them. These moons have been visited by NASA space probes and are a fascinating subject for research. Ganymede is easily seen with a small telescope.

Ganymede is the largest of Jupiter's moons. It's about twice the size of our own moon and larger than the planet Mercury. It has many impact craters, grooves and cracks on its surface.

It completes an orbit around Jupiter once every seven days. It's the furthest from the planet, and the coldest. It is composed of silicate rock, and ice (water ice). A saltwater ocean exists 200 km (124 miles) below Ganymede's surface, sandwiched between layers of ice. The planet's diameter is about 5,268 km (3270 miles) around, at its equator. Compare that to the equator of the earth: 12,756 km (7,926 miles). So it is less than half the size of our Earth.

 

Ganymede has a very thin atmosphere, composed of several gasses, including oxygen and ozone. Dark regions, covered with impact craters and dated to about 4 billion years ago, cover about a third of the surface. Lighter regions, criss-crossed by grooves and ridges cover the remainder. It's a disrupted terrain, and buried beneath it, under layers and layers of ice, is a saltwater ocean.

One wouldn't want to live there--the radiation level is 8 rem/day at the surface. What does this mean?

REM is a Roentgen unit. A dose of 100 rem is subclinical and won't cause permanent harm. A dose of 1000 rem is inevitably fatal.

But radiation effects accumulate. It wouldn't take long to exceed the maximum dose of radiation for good health if one lived on Ganymede.

And how COLD is Ganymede? 110 degrees Kelvin. (MINUS 262 degrees Fahrenheit, or MINUS 163 degrees Centigrade). The Kelvin scale begins at absolute zero, where it's so cold there are no moving molecules, no moving atoms. It's absolute zero, a complete absence of any thermal energy.

Ganymede, in myth, was the most attractive of all mortals. His homeland was originally Troy, and he was a prince.

Zeus (the Greek is Zeus, the Roman name is Jupiter) abducted Ganymede from Mount Ida in Phrygia. Ganymede was there, a youth and a prince of the blood, passing time as was typical of royal youth, away from the royal household, tending a flock of sheep by some reports; of gathering amongst friends and tutors, as he happily whiled away the chthonic, or rustic part of his royal education.

Zeus, (or Jupiter, to a Roman), fell in love with him instantly, and turned himself into an eagle to fly Ganymede to Mount Olympus.

In Olympus, Zeus (Jupiter) made Ganymede his beloved, granting him immortality and honoring him with the office of cupbearer of the Gods, supplanting Hebe.

"Ganymede" is the genesis of the intoxicating drink, mead, which originally came from Phrygia.

All the gods were filled with joy to see the beautiful youth, except for Hera, Zeus's female consort or wife, who was insanely jealous.

"Here the Phrygian hunter is borne aloft on tawny wings, Gargara's range sinks downwards as he rises, and Troy grows dim beneath him; sadly stand his comrades; vainly the hounds weary their throats with barking, pursue his shadow and bay at the clouds."

--From the Abduction of Ganymede by Zeus, undated cup worked with Ganymede's mythos.