Thursday, December 12, 2013
BY BERNIE REIM Correspondent
December marks the beginning of the winter solstice for us in the northern hemisphere. This year that will happen at 6:12 a.m. Dec. 21. That also marks the end of the Mayan calendar, which will just start another cycle. It will flip over to a new baktun that day as it does every 144,000 days, or about 400 years. No astronomical catastrophe will occur like an asteroid or comet hitting the Earth.
We will be more aligned with the center of our Milky Way galaxy at that time, but that happens every winter solstice. Some astrologers and psychics say that we will be more aligned with our galaxy than we were 26,000 years ago, which happens to equal one cycle of precession. That could line us up with extra energy from the center of our galaxy if that is true. We are also located 26,000 light years from the center of our galaxy.
There are several interesting highlights in December well worth braving the cold. Jupiter is at opposition on Dec. 2, the Geminid meteor shower peaks on Dec. 13, and our two largest asteroids, Ceres and Vesta, shine at their brightest in Taurus.
Jupiter reaches opposition on Dec. 2. This will be one of the closest oppositions for the entire 12-year orbit of Jupiter. The King of the planets will be directly opposite the sun from the earth that day, which means it will rise at sunset, reach its highest point at midnight, and not set until sunrise.
Try looking at Jupiter through a telescope in December to peer deeper into its mysteries and to better appreciate one of the family members of our solar system. Just before midnight on the night of the opposition, Callisto and Io will be to the left of the planet, and Europa and Ganymede will be to the right, balancing out the four Galilean moons. Each moon is unique and Europa, with a huge liquid ocean just below its icy surface, has the best chance for life as we know it anywhere in our solar system other than Mars.
The full moon on Christmas Day will pass just below Jupiter and just above the Hyades star cluster with the orange giant star Aldebaran, which marks the face and eye of Taurus the Bull.
We should enjoy an excellent Geminid meteor shower. It will peak on Thursday evening Dec. 13 into Friday morning Dec. 14. There will be no moon to interfere. You could actually see about 100 meteors per hour this year. The Geminids are caused by the dust and debris in the trail of an asteroid called 3200 Phaethon, which is probably the old nucleus of a comet. These particles leave brighter streaks because they are a little denser than the comet dust that creates the other meteor showers. Look into the eastern sky in the constellation of Gemini which is just to the left of Orion and part of the winter hexagon. It will already be above the horizon at sunset, so start viewing the meteors as soon as it gets dark that evening. You can add to the scientific knowledge of meteors by doing a real meteor count to report. Check out skypub.com/meteors and look under advanced meteor observing for more information. Astronomy is one of the few fields where amateurs can always add good information by careful observing that will help the professionals. It is also more exciting to participate at a deeper level to help you understand what you are really seeing when you watch an event like a meteor shower or an eclipse or a transit of Venus.
The two brightest asteroids, Ceres and Vesta, will also be at opposition in December. You can find them in Taurus with just a pair of binoculars. The Dawn spacecraft just visited Vesta and it will reach 600-mile-wide Ceres in 2015. Vesta, at about 400 miles in diameter, is a little smaller than our largest asteroid. Dawn showed Vesta had a bizarre surface with a huge crater showing a giant central peak at its south pole, along with a series of parallel grooves near its equator. Vesta is also a little too small to be completely round, so it is more potato-shaped. It is important to learn as much as we can about these two asteroids because each of them almost became a planet. The strong gravitational force of Jupiter kept that from happening.
Mercury and Saturn have now joined Venus in the morning sky. Look southeast one hour before sunrise on three consecutive mornings between Dec. 9 and Dec. 11, and you will witness the waning crescent moon as it first points out the star Spica in Virgo, then Saturn, and then Venus. By the time of the winter solstice, Venus and Mercury will have sunk lower into the morning sky and they will form a nice triangle with Antares in Scorpius in the southeastern morning sky.
I watched a live feed of the total solar eclipse from northern Australia back on Nov. 13. That was quite an experience, but certainly not the same as being there. The website slooh.com did a great job broadcasting this rare event. Tens of millions of people watched it live on their website. Other websites crashed before the event even started.
Part of the eclipse was overcast, but they did get to see some of the two-minute totality, when the sun was completely covered by the moon. The corona, or atmosphere of the sun, is safe to look at without any filters during this time. There were some beautiful streamers visible in the active corona, which extends beyond the disk of the sun by the diameter of its disk.
It is ironic that the real and subtle beauty of the sun is only visible when it is completely covered by the moon. Remember that the corona is always there, but it is usually overridden by the sun itself. The next live event that slooh.com will cover is the partial lunar eclipse on Nov. 28. Then they will cover some of the Jupiter opposition early in December. You can become a member on this site for a low fee and be able to control large telescopes in the Canary Islands and Chile. Younger people are already very good at technology. Now, with the simple motion of a mouse, they can control a great telescope and get useful data from it. This is a perfect way for anyone to get involved in real science and have a lot of fun learning along the way.
* Dec. 2 -- Jupiter is at opposition.
* Dec. 6 -- Last quarter moon is at 10:31 a.m. EST.
* Dec. 7 -- Jupiter passes 5 degrees north of Aldebaran in Taurus.
* Dec. 9 -- The asteroid Vesta is at opposition.
* Dec. 10 -- The moon passes south of Saturn this morning.
* Dec. 11 -- The moon passes south of Venus this morning.
* Dec. 12 -- The moon is at perigee, or closest to the earth this evening at 221,876 miles.
* Dec. 13 -- New moon is at 3:42 am EST. The Geminid meteor shower peaks.
* Dec. 15 -- The moon passes six degrees north of Mars this morning.
* Dec. 20 -- First quarter moon is at 12:19 a.m.
* Dec. 21 -- Winter solstice occurs at 6:12 a.m. This marks the lowest point of the sun for the year with the longest nights and shortest days.
* Dec. 25 -- The moon is at apogee, or farthest from earth at 252,337 miles today. Isaac Newton was born on this day in 1642. The moon passes 0.4 degrees south of Jupiter this evening.
* Dec. 28 -- Full moon is at 5:21 am. This is also called the Long Night Moon or Moon Before Yule if it takes place before Christmas.
Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.