jupiter moonsJupiter, a planet recognized since prehistoric times, is the third brightest object in the night sky after the Moon and Venus. Galileo, looking through the newly invented telescope in 1610, observed four large moons orbiting Jupiter. This was the first discovery of motion not centered on the Earth, and conflicted with theological teachings of the time.

Roman Jupiter (Greek: Zeus) was the God of gods, ruling over heaven and Earth. Jupiter is also king among the planets. Roughly 11 Earth diameters wide, all of the other planets in our Solar System would fit inside twice, with plenty of room left over. It would have to be at least 80 times more massive to become a star. Jupiter takes 12 years to orbit the sun, and rotates every 10 hours.

Jupiter is the “benefic” planet which brings expansion and good fortune. The textbook definition of a Stellium would be three planets at the same degree of a sign, as in the Sun, Mars and Jupiter each at 12° Virgo (or each within a 1-2° orb of this point). And Jupiter “the amplifier”, bringing expansion, vision, integration, and growth will be in the sign of Aries.

There certainly a lot to say regarding the upcoming Cardinal T-square (involving Uranus/Saturn/Pluto with Jupiter adding its touch). The Saturn /Jupiter cycle has been linked to economic ups and downs. As Pisces is a water sign, this transit of Jupiter in Pisces can bring benefits to those born under the other water signs, namely Cancer and Scorpio.

With Jupiter in Pisces our imaginations and creativity will be stirred, we may want to travel and indulge ourselves in our fantasies, undertake escapist activities or get involved in causes which help the needy. As Jupiter only travels into Aries up to the first 3 degrees this year, most Aries born will have to wait until March next year to experience its benefits.

Jupiter is a diurnal (opposite nocturnal), masculine planet, temperately hot and moist, airy, and sanguine, the lord of the air triplicity. If the planet is well dignified, the native will be of erect carriage and tall stature with a handsome ruddy complexion, high fore-head, soft, thick brown hair, handsome shape, and commanding aspect; his voice will be strong, clear, and manly, and his speech grave and sober.

If the planet is ill dignified, the native will still be a good-looking person, although of smaller stature and less noble aspect. In the former case, the understanding and character will be of the highest possible description; in the latter case, although the native will be careless and improvident, immoral and irreligious, he or she will never entirely lose the good opinion of friends.

Being very far from the Earth, Jupiter astrology associates us with a longing for distant horizons both physically and spiritually and a need to grow, live a larger life, move beyond limitations, and to expand in every way. Jupiter also represents our value system, beliefs, ethics and morality. That is connected to religion, philosophy, the search for meaning and order, and how we conduct our lives.

Jupiter rules Sagittarius and the 9th House (the Higher Mind & the Search for Meaning) and secondary the12th House (the Personal Connection with the Divine & the Invisible Realms) before Neptune was assigned to it. In the body Jupiter rules the liver and fat. Jovial individuals (ruled by Jupiter or the sign Sagittarius) seeks answers to the big questions of life. In that quest, they tend to be perpetual scholars, whether in formal schooling or self-taught.

Once they find an answer they like, they aren’t shy about carrying the word enthusiastically to others. Thus they are often formal or informal teachers, preachers, or public relations people. They can be conventional, moralistic, and preachy, but generous, with a good, though convoluted sense of humor. Optimistic by nature, they seek to uplift and encourage others and to find lessons in every trial.

Close to the composition of the primordial Solar Nebula from which the entire solar system was formed, Jupiter has a similar composition to Saturn of about 90% hydrogen and 10% helium. Like Saturn, it has rings, but they are much fainter and smaller. The giant gas planets do not have solid surfaces, their gaseous material simply gets denser with depth. Jupiter probably has a core of rocky material amounting to something like 10 to 15 Earth-masses.

Above the core lies the main bulk of the planet in the form of liquid metallic hydrogen. This exotic form of the most common of elements is possible only at pressures exceeding 4 million bars, as is the case in the interior of Jupiter (and Saturn). Liquid metallic hydrogen consists of ionized protons and electrons (like the interior of the Sun but at a far lower temperature). At the temperature and pressure of Jupiter’s interior hydrogen is a liquid, not a gas.

Jupiter has high velocity winds of more than 400 mph driven in large part by its internal heat rather than from solar input as on Earth. The Great Red Spot seen by Earthly observers for more than 300 years is an oval about 12,000 by 25,000 km (big enough to hold two Earths). Similar structures have been seen on Saturn and Neptune.

Jupiter radiates more energy into space than it receives from the Sun. The interior of Jupiter is hot with the core about 20,000 K. The heat is generated by the slow gravitational compression of the planet. Jupiter does not produce energy by nuclear fusion as in the Sun; it is much too small and its interior is too cool to ignite nuclear reactions.

Jupiter is just about as large in diameter as a gas planet can be. If more material were to be added, it would be compressed by gravity such that the overall radius would increase only slightly. A star can be larger only because of its internal (nuclear) heat source. Jupiter has 63 known satellites most are named for Zeus’ numerous lovers but many have yet to be named. It is gradually slowing down due to the tidal drag produced by the satellites.

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