NIGHT SKIES OF DECEMBER 2012 - THE WORLD WILL NOT END ON DECEMBER 21
THE WORLD WILL NOT END ON DECEMBER 21
By Dr. N. T. Jiwaji
All over the world, people continue to be worried by the story about the end of world next week. This rumour has distressed so many people, especially young children, that even the US Government had to issue reassuring statements that this is a rumour, and the world WILL NOT END in December. Even the Vatican had to issue a statement that the world will not end and people should continue preparations for Christmas and the holiday season. I have written scientific arguments about why the world will NOT end anytime soon (www.astronomyintanzania.or.tz).
The problem is that people tend to accept too quickly, sensational stories that that are based on common facts but used with false or no logic. We call such beliefs superstitions, which persist because of fear of the unknown. The current rumour started with misinterpretation of the Mayan calendar that will end its 13th “Baktun Cycle” on December 21. With 13 often taken to be an unlucky number and placed together with the word “end”, you can see how people can be deceived into believing that world will end on world on 21st December. It is not going to happen.
December 21 has an astronomical significance because the Sun is at its southernmost position, called solstice. It occurs due to the 23.5 degree tilt of the earth’s rotation axis in relation to its plane of revolution around Sun. Hence, at this time the Sun is directly overhead at latitude 23.5 degrees south, also known as the Tropic of Capricorn.
Astronomical information is easy to misuse because it is based on events that take place very far away out of reach of ordinary human beings. Advances in astronomy have allowed extremely accurate predictions about positions of planets and stars. Astrologers misuse these accurate astronomical predictions to make completely unrelated predictions about a person’s character and relationships. We should all become knowledgeable in basic science so that we do not fall into the trap of imagined disasters.
A sad story this month is the death of a famous British presenter, Sir Patrick Moore, presenter of the BBC’s monthly Sky at Night program, who died at the age of 89. He presented all the programs himself continuously for a record 55 years. His last show was aired just one week before he died. He was a self taught astronomer who popularized science by comparing astronomy concepts using familiar objects and experiences. His amateur observations of the Moon were so detailed that his hand drawings were used by NASA to plan the first landing on the Moon by Apollo 11 mission in 1969. The world will miss an icon of astronomy.
Water, the elixir (crucial ingredient) of life has been found in a completely unexpected place - Mercury. The smallest planet in our solar system that orbits extremely close to the Sun would be expected to be to too hot to contain water. However, the Messenger mission found frozen water at the poles just below the surface in the deep craters that are completely shielded from the Sun.
Deep space science had to be re-written quickly after a closer look at the data from the Voyager 1 and 2 spacecrafts
launched 35 years ago and are now nearly 18 billion kilometres away from us. The spacecraft were initially thought to have passed out of the Solar System after the spacecraft detected that the number of low energy particles originating in the solar system dropped by half. However, the magnetic-field has now been found not to have changed significantly, so the spacecraft are now thought to be inside a new region that was not known to exist before at the edge of the solar system. Soon they will be in true interstellar space on their way to the stars. Photo courtesy: http://www.space.com/17456-voyager-1-spacecraft-solar-system-edge.html In the early evening skies you will not fail to notice a brilliant star rising in the east. This is none other than planet Jupiter which forms a very eye-catching pair with a nearby red giant star Aldebaran, the brightest star in Taurus. It rises in the sky as the night passes and is imposingly overhead by 10 pm.
At the opposite end in the west, red Mars is still seen high enough at about 20 degrees elevation, but sets by 8 pm.
A thin crescent Moon will be close to Mars on Saturdy 15th, and will form a noticeable pair with the cusps pointing away from the planet.
After the New Moon on 13th December, the Moon will be in the First Quarter (half shape) phase on 20th when it will be overhead at sunset. This is the best time to see the craters on the Moon through a telescope. The Moon will be close to Jupiter on 25th December, and Full Moon will be on 28th.
The early morning skies shine just before sunrise with a stunning line-up of three planets – Saturn, Venus and Mercury. They form a vertical line rising from the east with Mercury at the bottom close to the horizon, dazzling Venus in the middle and sharp Saturn at the top.
The night skies are beginning to display many prominent constellations in the sky. The glory of the southern hemisphere’s night sky becomes apparent when you go out after 9 pm. The brightest star in the sky, Sirius, is now quite prominent in the south-east as the neck star in the dog shaped constellation Canis Major (Big Dog). An arch of the dense band of stars in the Milky Way starts the evening straddling the eastern horizon. It then rises cutting approximately north to south and band reaches the zenith by midnight. The band begins with Canis Major, the dog, crossing to magnificent Orion, the hunter, which then leads to Taurus the bull, which contains the distinctly visible red giant star, Aldebaran. The last two constellations in the star band are Perseus containing the famous variable star Algol and ends with M shaped Cassiopeia in the north. Close to Taurus is the famous twinkling star cluster, Plaiedes, also known as the Seven Little Sisters’. Just off the arch westwards but still close to the Milky Way can be found the Square of Pegasus. The Andromeda galaxy is 2 million light years away from us, yet we can still see it with naked eye and appears as a small patch of nebulosity in dark skies. It lies about 40 degrees above the north horizon between the Square of Pegasus and Perseus.
The most easily identifiable constellation is ORION which we see as a huge rectangle laying on its side in the eastern
sky. It has two very bright stars at the end of its diagonals: Rigel on the top right and the red giant star Betelgeuse sparkling red on the bottom left of the rectangle. The other diagonal is marked by three stars close together in the middle, called the ‘Belt of Orion’. It is embedded in a dense cloudy nebulosity of interstellar matter which is and active nursery of new stars as the unstoppable pull of gravity gathers the interstellar gas and dust with the passage of millions of years. The Orion nebula can easily be made out with the naked eye and is breathtaking in a small pair of binoculars, or even better, a telescope. Among the Zodiacal constellations spanning east to west are Gemini the twins cutting into Taurus, leading to less prominent Aires, Pisces, Aquarius, and Capricorn and ends with Saggitarius setting in the west swamped by sunlight. There are also several stars that you should try to identify because they are among the brightest in the sky. In the last half of the month Procyon rises in the south east with Sirus, already high and Canopus in the south: These three brilliant stars form an almost straight line and together with Capella also rising in the north east, forms a reasonable right angle triangle.
The best view among the satellites is the Chinese space station Tiangong, which is beginning to be assembled with parts ferried every few months into orbit. On Monday 17th December, it rises at 7:15 pm in the south west and rises across the middle of the sky, reaching overhead at 7:20 and one minute later it will pass close to Jupiter and soon disappear suddenly close to the north east horizon when it enters the Earth’s shadow. To get the exact time of observation or for viewing details for other locations in Tanzania, go to the webpage http://www.heavens-above.com and enter your latitude and longitude position.
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