What happens in December: it’s worth braving the cold to see the sky

SKY GUIDE: This chart represents the sky as it appears over Maine during the month of December. The stars are shown as they appear at 9:30 pm at the beginning of the month, at 8:30 pm in the middle of the month and at 7:30 pm at the end of the month. Mars is shown in its mid-month position. To use the map, hold it vertically and rotate it so that the direction you are facing is down. Sky chart prepared by George Ayers

December always marks the beginning of winter for us in the Northern Hemisphere. This year it will happen exactly at 5:02 am on December 21st. This also marks the lowest point in the sky that the sun will reach and the longest night of the year – more than 15 hours. While this month will be much colder than our relatively warm November, this December will have far more than the usual number of exciting events, so it’s worth braving the cold and making the effort to witness them in person.

The main highlight will be the closest conjunction of Jupiter and Saturn in 400 years and the closest visual conjunction of that pair in 800 years. They will be only 6 arc minutes or a tenth of a degree from each other on the winter solstice. The full moon covers five times more than the sky, or half a degree. Mars still shines high and bright this month. There are two new comets visible now with just binoculars, Atlas and Erasmus. There will be a total solar eclipse over Chile and Argentina, just 600 miles south of the path of another total solar eclipse that took place on July 2, 2019. There will be a diurnal occultation of Venus by the crescent moon. on the western part of this country. The long list ends with not one, but two meteor showers that we can see right from here. Those are the Geminids of December 13 and the Ursids of December 22.

Jupiter and Saturn begin this month just 2 degrees apart, and by December 12 they will be only a degree or two times the width of the full moon. So Jupiter continues to get closer and closer to Saturn until the winter solstice, when they will be only a tenth of a degree away, or 12 times the width of Jupiter. They will simply swap places and remain within one degree of each other until December 29. So our two largest planets will be visible in the same field of view in a telescope, along with all of their moons for most of this month. They were so close nearly 400 years ago, but the last observable conjunction at this closure was recorded in 1226, nearly 800 years ago. The pair can get close enough every 20 years, as Jupiter takes 12 years to orbit the sun and Saturn takes 30 years.

The last time there was a reciprocal occultation when Jupiter actually passed right in front of Saturn was about 8,000 years ago. The poinsettia may have been a close conjunction of this pair in 7 BC or a triple conjunction of Venus and Jupiter in 2 and 3 BC. So this can be seen as a reenactment of this great event during this important season.

Even though Mars is getting a little fainter again each evening as we move further into our faster orbit around the sun, the red planet still appears much brighter and closer than usual and will still offer some good visuals of its features. in small telescopes for the rest of the year. It was at its best in 15 years just a month and a half ago in mid-October. It is now moving in forward or eastward motion in Pisces.

Venus begins the month that rises two hours before sunrise and then continues to rise a little later each morning in the constellation of Scorpio. Our sister planet is getting a little more sunlit every morning, even as it is getting smaller in our sky and further ahead of Earth in its orbit around the sun. Venus stays at magnitude -3.9 throughout the month, which is about 6 times brighter than Jupiter and 72 times brighter than Saturn. This means that Jupiter is about 12 times brighter than Saturn, which will be just to the left of Jupiter for the entire month until the King of Planets passes the ringed planet on the longest night of the year.

The two comets visible this month are called Erasmus and Atlas. Atlas stands for a pair of 20-inch telescopes in Hawaii. It sounds rather creepy but it is very useful. It stands for Asteroid Terrestrial-impact Last Alert System. There are several similar telescopes now that they have found many asteroids and comets. In just five years of operation, Atlas has already found 536 asteroids near Earth plus 57 potentially dangerous asteroids that could hit Earth at some point, 53 comets and 7,156 supernovae in other galaxies. We are much safer with all these telescopes working so well.

Dr. Nicolas Erasmus is an astronomer who used the same Atlas telescope to find his comet on September 17th. Now you can see it near Venus in Virgo in the morning sky and you can see the comet Atlas in Auriga near Orion in the evening sky. They are now both about eighth magnitude, or six times fainter than anything you can see without optics.

This winter solstice will be one of the most extraordinary of the last 1,000 years. You will see Jupiter and Saturn at a tenth of a degree from each other, practically like a planet, the comet Atlas in the evening sky, the comet Erasmus in the morning sky near Venus and the Ursid meteor shower emanating from the Dippers. Nature will offer a spectacle for the longest night of the year.

The new moon of December 14 will cause another total solar eclipse. It will take nearly the same route as last summer on July 2, only about 600 miles further south. The moon’s shadow cone will race across the cramped countries of Chile and Argentina from the high Andes to the Patagonian highlands in minutes at around 1,500 miles per hour. The greatest amount of time anyone can be immersed directly in the shadow of the moon this time will be just 2 minutes and 8 seconds, even a little shorter than what I experienced on Idaho near Yellowstone three summers ago.

This was by far the most spectacular and enlightening event that nature could create for earthbound humans. Seeing all the planets visible near the sun along with many stars appearing immediately after the last brilliant flash of sunlight burns the sky like a gorgeous diamond ring is truly unforgettable. I could see and feel the entire precious and muted atmosphere of the earth at the same time as a 360 degree salmon twilight surrounded everything in an eerie twilight and softly merged into the purple and black sky above us. I have gained a sense of the inner workings of the solar system and the sun and the immense speed and power with which all of these objects always move despite their seemingly static nature. Ironically, the true beauty of our day star, the sun, shines only when it is completely, perfectly and precisely covered by the moon, allowing its living, breathing, pulsating, sparkling, ethereal crown with its tremendously intricate streamers and insides. structure that stretches four million miles into space to become visible to humans for a few short and precious moments every few years. Then, as suddenly as it had begun, it all ended with an even brighter flash of light that hit the dark skies as the moon’s shadow cone rose from our portion of land onto a plateau with a partial view of the Grand Tetons and everything soon returned to normal as the sun was restored to our midday sky, leaving only an indelible memory of what always happens.

I highly recommend everyone to have a similar experience at least once in their lifetime. There will be one that passes right over central Maine in a few years, on April 8, 2024. That will start in Mexico and end in Canada. The weather outlook further south is much better for that event than Maine in early April, TS Eliot’s “cruelest month”. Since far fewer people than usual will be able to travel to see this big event, there are many good websites on which you can watch this event live, including the San Francisco Exploratorium and Slooh.com. Over 50 million people from around the world were able to witness the latest Great American Total Solar Eclipse on August 21, 2017, but far fewer people will see it in person.

The best meteor shower of the year, the Geminids, will peak from Sunday night December 13 to Monday morning December 14, just before the eclipse in South America. This is one of only two meteor showers not caused by a comet. The Geminids are caused by an asteroid called 3200 Phaethon. It is only 3 miles wide and orbits the sun every year and a half. Meteors travel slower than most showers, at just 21 miles per second, which is just a bit faster than the earth is always in orbit around the sun, which is 18.6 mps, 10,000 times slower than the sun. light speed. There will also be fewer fireballs because this asteroid’s tiny sand particles are denser than the usual comet dust particles we see. You can expect up to 100 meteors per hour from Gemini as there will be no moon to interfere with this great natural spectacle.

HIGHLIGHTS OF DECEMBER

December 7: The last quarter of the moon is at 19:38

December 11th: Annie Jump Canon was born in 1863. She was instrumental in establishing the spectral classification system of stars along with many other female astronomers known as “Harvard Computers.

December 12: The waning crescent moon will be close to Venus this morning. A diurnal occultation of Venus will occur in some parts of the world and on our west coast.

December 13: Geminid Meteor rain peaks tonight through December 14th.

December 14: A total solar eclipse will occur over Chile and Argentina. Tycho Brahe was born in 1546. The new moon is at 11:18 am

December 17: The Wright brothers made the first powered flight in 1903. Less than 66 years later we would fly to the moon.

December 21: Jupiter and Saturn will be a tenth of a degree apart this evening. The winter solstice is at 5:02 in the morning. The first quarter of the moon is at 6:42 pm

December 22: Ursid Meteor rain peaks this morning.

December 23: The moon is close to Mars this evening.

25th December: Isaac Newton was born in 1642.

December 27: Johannes Kepler was born in 1571.

December 28: Arthur Eddington was born in 1882. He took a photograph of a total solar eclipse in May 1919 which proved that Einstein’s Theory of General Relativity was exactly correct.

December 29: The full moon is at 10:29 PM This is also known as the long night moon, the moon after Yule or the cold moon.

Wells’ Bernie Reim is co-director of the Astronomical Society of Northern New England.

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