If the weather is clear Wednesday night next week, it is likely that our skies will be filled with the largest number of visible shooting stars we have had in some years.
The great occasion is that the United States obtains perfect astronomical conditions for the strong Geminid meteor shower.
What happens if it is cloudy on the great night of the Geminids, from the 13th to the 14th of December? We can still see some of these meteors on neighboring nights, in addition to seeing several beautiful couples of the crescent moon with the planets Jupiter and Mars.
What causes meteor showers?
Each year approximately on the same dates, the Earth passes through swarms of rocky particles associated with the orbits of several comets. When these meteoroids meet the Earth's atmosphere at tremendously high speeds, up to more than 100,000 mph, they burn out of friction and produce the brief rays of light we call meteorites.
A meteor shower is not just an increase in meteors, however. They are the meteors of a particular swarm that seem to shoot from a particular point between the constellations, a point called the radiant. In the case of the Geminids, all the paths of the meteors seem to point to the famous constellation of the zodiac Gemini the Twins. Gemini is now rising at sunset and is already high by taking half, then, unlike any other meteor shower, the Geminids can be seen in large numbers at 9 or 10 pm
Why this year? Is it so favorable for the Geminids? ?
In some years, the moon is in a large phase for most of the night and its bright light eliminates our view of most meteors. This year, on the big night, the moon does not rise until about 3:30 a.m. M., And even then it is only a thin half moon, with 10 percent of the moon illuminated, so it does not really bother our view of the Geminids.
The other reason why this year is astronomically favorable for the USA. UU To see the Geminids is the exact moment of the encounter of the Earth with the central section of the swarm of meteoroids. The Geminid rain produces near-peak numbers for about 24 hours, so even the night before the rain maximum could give us a pretty good number of meteors. But the climax of this year's rain is expected to occur around 1 a.m. of December 14, which is only one hour before the radiant in Gemini is higher for observers in the eastern United States. So next week, from Wednesday to Thursday the best numbers.
How many meteors will you see?
Last year there were similar favorable conditions for the Geminids I saw 68 of them at my best hour, along with about 14 meteors from other directions. Within the light pollution of a good sized city on a big night, you may only see a maximum of 10 or 15 Geminids per hour. But some of them will be bright meteors, perhaps some brighter than any star or planet, or even as bright as the moon. Gemstones come in all colors, sometimes they have blazing flares, outbursts of flight and sometimes they leave luminous traces.
A schedule for Geminid observers
In the afternoon, around 5:30 to 7 pm, the radiant in Gemini is still low, so not many meteors will be visible. The few Geminids that occur then, however, will tend to be "earthgrazers" – meteors with incredibly long flights, sometimes almost all the way across the sky. At 9 or 10 p.m. the numbers could be up to four dozen or more per hour. From 11 p.m. at 4 am Geminid rates of 60 or more would be possible if the skies were clear enough.
A moon and planets bonus
One hour before sunrise on December 13, the crescent moon is just above the current level of Mars, with Jupiter far below on the left. But at the same time, the next day, the moon is dramatically near the top right of the bright Jupiter.
Fred Schaaf is an author and local astronomer. He can be contacted at: firstname.lastname@example.org.