December Night Skies Over Tanzania
After experiencing the wonderful views of three eclipses over Tanzania, each unique in its own right, we are in for a drought of eclipses until 2015 September 28, which anyway will just be the tail end of a lunar eclipse. However nature has its way of compensating for shortcomings and will grant us a remarkable sight of a major annular eclipse on September 1 2016, when an annular solar eclipse will pass right over southern Tanzania. We have enough time to work on and write about for the next three years to prepare the public to take the maximum benefit of this spectacular opportunity. Eclipse chasers from around the world will want to come to Tanzania to see and study the September 1, 2016 annular solar eclipse.
The comet of the century that was expected from ISON did not materialise as it was ripped apart by the immense gravity and the violent atmosphere during the comet's closest approach and turn around the Sun. However, what appear to be remarkable remnant is still expected to produce a cometary show with a visible tail. Keep a watch on www.astronomyintanzania.or.tz for more immediate updates.
Space exploration is becoming a common goal for many countries around the world. There are only a few nations capable of launching a spacecraft into Earth orbit and beyond. These include the pioneers Russia, determined followers USA, France, Japan, China, India, Israel, Iran and North Korea. Moon and Mars are the most attractive but challenging targets. The space race now is between China and India with China focusing on exploiting the mineral resource on the Moon, while India wants to prove that it can reach Mars before China, and took on the challenge at short notice after the failure of the Chinese Mars attempt. In fact, as we speak, two spacecrafts are on their way to Mars during its current close approach to Earth. The US Maven spacecraft is on its way, while the Indian Mangalyan used slingshot orbits around Earth to achieve the necessary speed to reach Mars. It just executed a perfect injection into the critical Mars trajectory after a few nail-biting manouvers.
Both spacecrafts will be looking for water and methane in Mar's thin atmosphere. Maven will also study the speed with which Mars is losing its atmosphere. Mars does not a magnetic field like that on Earth hence the solar wind, which is actually extremely fast charged particles from violent explosions on the Sun, are able to strike the particles of the atmosphere directly hence pushing them away from the planet and are lost into space.
Mars once used to have a thick atmosphere with water vapour and clouds but it has all but disappeared and left behind a desolate Mars. Earth is currently in the midst of losing its magnetic field during a regular reversal of poles every few tens of thousands of years. It is thought that during such a reversal the planet may lose its magnetic permanently. Hence the fate of Earth may be similar to that of Mars.
The other story about planets that orbit far off stars. These alien planets continue to amaze us with recent discovery of water on several planets. With more than 1000 exo-planets having been already directly detected by the remarkable Hubble Space Telescope, the chances of finding alien life is increasing each day. We anxiously await with enormous expectations….
The night skies are beginning to display many prominent constellations in the sky, but to get the most enjoyment out of it this month, watch a bit late in the night. The brightest star in the sky is now quite prominent in the south-east as the neck star in the dog shaped constellation Canis Major (Big Dog). An arch of stars spanning eastwards reaching north among dense collection of stars of the Milky Way begins with Canis Major giving way to the magnificent Orion, the hunter, which in turn leads to Taurus the bull which contains the distinctly visible red giant star Aldebaran. The last two constellations in the arch are Perseus containing the famous variable star Algol and ending with M shaped Cassiopeia in the north. Close to Taurus is the famous star twinkling 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, which is 2 million light years away yet still just visible to the naked eye as a patch of nebulosity in dark skies, lies between the Square and Perseus, 40 degrees above the north horizon.
Among 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 giant star Betelgeuse sparkling red on the bottom left of Orion. 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 inexorable pull of gravity gathers the pace after millions of years. The nebula in Orion can easily be made out with the naked eye and is breathtaking even in a small pair of binoculars, let alone 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.
ISS, the International Space Station continues to amaze casual observers when they see an extremely bright star move slowly across the sky but realise that it is not an airplane. Early morning risers before dawn can see the ISS cross the sky on December 10, when it will appear suddenly from nowhere overhead at 4:36am and move towards the southeast, disappearing below that horizon after 4 minutes at 4:40am. Evening passes of the ISS will be best seen on New Year's eve on December 31, when it will rise above the northwest horizon at 8:04pm and move up the sky towards the southeast reaching almost overhead at 8:08 pm, then move down towards southeast disappearing just above the horizon at 8:10 pm. It will again be seen the following day on New Year evening when it will rise in the north-northwest horizon at 7:15pm, then move towards the northeast achieving maximum 55 degree elevation above the northeast horizon at 7:18pm, after which it will move towards the southeast and will disappear suddenly above the southeast horizon at 7:21pm. On January 3, the ISS will cross the southwestern sky, rising at 7:12 pm, and reach maximum elevation of 50 degrees at 7:15pm, and finally disappear in the southeast at 7:18pm.
Wishing you all a very happy holiday season and fruitful