Astronomers use the term conjunction when two objects appear to meet in the night sky. The Great conjunction is when the two biggest planets of our solar system, Jupiter, and Saturn, the second biggest with its famous rings, meet and form a “double planet” as seen from Earth. Obviously, this is an optical illusion because the planets remain millions of miles away.

2020 is a special year and this is true also in astronomy. About every 20 years, Jupiter’s orbit around the sun laps over Saturn’s orbit. But, this year, Jupiter and Saturn will appear closest on December 21, which happens to be the winter solstice or the longest night of the year. The last time they were this close and also visible on Earth was 800 years ago. This happened in the medieval times on March 4, 1226.

Jupiter and Saturn will be visible to the naked eye throughout the month of December in the northern hemisphere shortly after sunset, low in the southwestern sky, says NASA. Jupiter is brighter than any star in the night sky. Saturn, even now, is visible as a bright star but slightly dimmer and located to the east (left) of Jupiter.

Interesting Facts about the two planets.

Jupiter.

Jupiter is the fifth planet from the sun and the largest in the solar system. It is currently 778 million km from the sun, the equivalent of or 5.2 times the average distance between Earth and the sun. Jupiter is a gas giant composed mainly of hydrogen and helium with a rocky core of heavier elements. Its radius is 11 times that of Earth. It has 79 moons including 4 moons about the size of Mercury, discovered by the famous astronomer Galileo Galilei in 1610.

Like Earth, Jupiter possesses a magnetic field but it is much bigger and stronger that Earth’s and also produces aurorae. A year on Jupiter is 11.86 Earth years and a day is about 10 hours, the fastest rotation of all the planets in the solar system.

Jupiter is easily visible to the naked eye and is the third brightest object in the night sky after the moon and Venus. The outer atmosphere displays several bands at different latitudes producing large storms. One of them is called the Great Red Spot, a giant storm as big as Earth itself. It has existed at least since the 17th century when it was first discovered.

Saturn.

Saturn is the sixth planet from the sun and the second-largest in the solar system after Jupiter. It is located 1.4 billion km from the sun or 9 times the distance between the Earth and the sun. Like Jupiter, it is a gas giant with a radius of about 9 times that of Earth. The Romans named the seventh day of the week Saturday from Saturn.

A day on Saturn lasts 10.7 hours and a year is 29.4 Earth years. Saturn is made mostly of hydrogen and helium with a solid core and has a weak magnetic field. It’s density of 0.689g/cm3 is so low it could float on water.

Saturn is famous for its rings composed mostly of water ice ranging in size from small specks up to 10 meters and it has 82 known moons. The rings extend from 4,120 to 75,000 miles outward from the planet’s equator and are approximately 66 ft in thickness. The other gas giant planets have faint rings but Saturn has the most impressive ones.

Celestial events such as the great conjunction are important in the history of many civilizations. The great conjunction of 2020 is also known as the “Christmas Star” because of the belief that the “Star of Bethlehem” could have been a planetary conjunction. But, about two thousand years ago, Venus and Jupiter were closest, not Jupiter and Saturn, which is the case of the “Christmas Star” of 2020. This year, the event will be clearly visible in December by looking toward the waxing crescent moon in the western sky, 45 minutes after sunset, according to NASA.

In the science-fiction and fantasy novel, “I Am Sheffrou”, an important celestial event called the Great Eclipse plays a crucial role in the story. The Great Eclipse occurs when the two moons of the fictional planet Chitina, Ara and Kori, align with the orange sun plunging the planet in total darkness for several hours. To find out more, go to “I Am Sheffrou”, An Alien Love Story, available on Amazon, Apple, Barnes & Noble, Kobo.

Source: Sophie Lewis CBS News, Tim Fitzsimons NBC News, Wikipedia, NASA, and Hubble pics.

Cami Michaels

As a teenager, Cami Michaels dreamed of becoming an astronaut, an anthropologist, and a psychologist. After a successful career as an obstetrician-gynecologist and four children, Cami divides her time between her family and her passion for science-fiction and fantasy. Her first novel, available summer 2020, I Am Sheffrou, is an erotic alien love story, part of a trilogy.

Born in Montreal, Cami Michaels now lives in South Carolina and enjoys writing, traveling to faraway places, and nature photography. If you look closely, you will see her riding her recumbent tricycle around the neighborhood or working in her bee and butterfly friendly garden.