Jupiter And Saturn Will Be Close On December 21, A Once-in-a-Lifetime Watch

Satellite image of Saturn and Earth (Source: Commons Wikimedia)

JAKARTA - Jupiter and Saturn are often seen far apart. But by the end of December the two largest planets in the solar system will be so close together that they appear to be overlapping.

This was stated by NASA. This phenomenon will create a kind of "double planet" that has not been seen since the Middle Ages.

To quote The New York Times, Monday, December 7, over the next two weeks, as their orbits align closer together, the planets will pull closer until they appear to be only a tenth of a degree apart. Such meetings, known as the great conjunction, occur every 20 years.

But the conjunction of Saturn and Jupiter this time is special, astronomers say. This year's phenomenon will be special because the two planets are also very close to Earth.

The last two planets seen close to Earth occurred in 1623, 14 years after Galileo built his first telescope. At that time the conjunction was 13 degrees from the sun, making it nearly impossible to see from Earth, said Amy C. Oliver, a spokeswoman for the Center for Astrophysics, Harvard and Smithsonian.

The next two planetary events close to Earth will return as early as 2080, Oliver said. This makes this year's conjunction a once-in-a-lifetime spectacle for most adults.

In all of the United States (US), the best view of the two nearly parallel planets is after sunset. Look to the southwestern part of the sky, astronomers say.

"This is a very elegant astronomical event to see in the night sky," said Renu Malhotra, a professor of planetary science at the University of Arizona. "It is a very romantic occasion to see these planets approaching each other."

Although it is best seen with binoculars or a telescope, the encounter of Jupiter and Saturn is also visible to the naked eye. Konstantin Batygin, a professor of planetary science at the California Institute of Technology, said he has observed Jupiter, his favorite planet, and Saturn getting closer to each other while taking walks at night.

"This is a rare astronomical event in which you can appreciate the motion of the planets around the sun without being an astronomer," said Professor Batygin.

“You can still go out to Christmas and say, 'Wow, those two planets are really close to each other, and usually aren't.' This is one of the rare times when the majesty of the solar system presents itself to the naked eye. "

But such planetary encounters are not always welcome. In ancient times, people considered the alignment of planets to be a bad omen or a harbinger of disaster, says Professor Malhotra.

"There is reason to fear that the gods are conspiring as they get closer to the night sky," he said. "This may have an unpleasant meaning for people on Earth."

Conjunctions are the result of Jupiter and Saturn's orbital paths becoming aligned, when viewed from Earth. Jupiter orbits the sun every 12 years and Saturn every 29 years. Even though the two planets appear close together, the two planets are not actually that close. In fact, their distance will be more than 400 million miles.

"Jupiter and Saturn will appear as two wandering stars that are directly on top of each other," said Professor Batygin. "If you wait long enough, it will happen, because the orbits intersect. But that doesn't happen often. "

Some people call the phenomenon of conjunction as the Christmas star because it arrives around holidays. In the days before and after December 21, as soon as it got dark outside, everyone should go out and see him.