Like a fairy tale, it is a long time ago. But that’s really the point. Year 1226. On March 4 of that year, Jupiter and Saturn came closest to each other. About 800 years have passed since then. After all these years, the two planets will come closer than this and will appear on December 21,2020.
This cosmic phenomenon of multiple planets and stars coming very close together is called ‘conjunction’ in the language of astronomy. Although the conventional meaning of conjunction in Bengali is connection or union, another difficult meaning is ‘simultaneous occurrence.’
Simultaneous means at the same time or with and occurrence means event. Since Jupiter and Saturn are the two largest planets in the solar system, astronomers call it the Great Conjunction. Such a huge event happens for two decades in a row.
Patrick Hartigan, a professor of physics and astronomy at Rice University, says the simultaneous occurrence is truly exceptional because, for the first time, they are so close.
They will even come so close that it would be difficult for many to see them apart without seeing anything! It would seem that the two planets are paired. So it’s really a rare organization, he added.
Thus, the distance between Jupiter and Saturn is more than four times the distance between the Earth and the Sun (149,597,870 km). But on this special night, the distance between them will be only about 695 kilometers, says Hartigan.
NASA has renamed this conjunction ‘Christmas Star’, because the planet-pair will appear brighter than the daily stars in the sky.
According to Hartigan, the telescope should be placed on the southwest horizon an hour after sunset to see the event. However, if there are clouds in the sky, it will not work.
His advice is to fix the telescope before dark. A binocular can be placed with, which will help find the four moons of Jupiter.
If there are clouds in the evening sky on December 21, there is no reason to worry. Conjunction has started from 17th December and will continue till 25th December. That’s right, they will come closest on December 21 at 1800 Central Standard Time (CST). 21 December CST 1800 means 6 pm Bangladesh time on 22 December. The sunrise on this day is at 6:39. If the southwest horizon is cloudless, hopefully this rare cosmic moment will be captured by a telescope.
For those who can’t go out, there are easy arrangements. The Great Conjunction will be streamed live on YouTube through the Arizona Lowell Observatory Telescope. Eastern Time (ET) 1900 hours, that is, Bangladesh time on December 22 at 6 pm they will start. The Virtual Telescope Project also plans to go live in Rome.
The next conjunction will be seen in 2080.
News Room, December 21,2020