By Dr N T Jiwaji


After the long heavy rains the skies are opening up for a blazing show.  With the air washed out of its yearly collection of dust and grime, stars have begun to shine brilliantly and twinkling excitedly.  Planets of course shine persistently like inviting beacons. 


The more wonderful sight is the perfect line-up of planets.  It is worth watching this show in the early night skies around 8 or 9 pm.


Looking at the sky from west to east, connect the planets by an imaginary line in the sky - from Jupiter in the west, to Mars overhead, and Saturn (and Moon) in the east, and you will see that it forms an almost perfect straight line which your eyes will interpret as semi-circular arc in the celestial sphere.


The sky is cloudy at times but it turns absolutely clear also. More clear days lie ahead. So go out and make the most of this opportunity.  The three planets, Jupiter, Mars and Saturn will be together in the evening sky until end of June in a straight line with the Moon shifting between them as it changes phases. The meeting of the Moon with these three planets will provide exciting spectacles on 1st, 7th, and  10th June respectively.


The path traced out by the line in the sky is called is the ECLIPTIC.  All solar system object (the planets, Sun and Moon) will always be seen along this narrow path only.  This shows that in our solar system all objects lie within a very flat plane. 


Notice that Mars is extremely bright and red.  It just passes its closest distance from Earth and is at opposition (facing the Sun).


Also seen very clearly towards the south is the Southern Cross whose diagonal stars point towards the south direction.  In the north, the Big Dipper points its edge stars northwards.  The sky map also points out three prominent stars.  These are, the brightest star Sirius, the second brightest star Canopus and the closest star Alpha Centauri(or Rigel Kent).  The two stars perpendicular to the cross are called pointers since they prominently guide gazers towards the cross.


Among the constellations, The most recognizable constellation, Orion, bids us farewell and sets by 8 p.m. Leo dominates the skies, though the full glory of this constellation with an inverted question mark forming the head of the lion, and its lounging body, can easily be obscured by city lights.


The Pointers, the Southern Cross in the southern sky and the Big Dipper in the northern sky, are well positioned from early evening and are high in the sky so they can be used to locate south and north (see map). Scorpio pops its front claws early in the evening and by 10 p.m. the sweeping, curving tail with the sting at its end formed by a close pair of stars is easily made out.


From our unique geographic position close to the equator, we can see 16 of the 21 brightest stars in the evening sky between 7 and 8 p.m. They are (in order of brightness, with their constellations in brackets) SIRIUS (the Dog), CANOPUS (Carina), ALPHA CENTAURI (Crux), ARCTURUS (Bootes), CAPELLA (in Auriga, just off the map, and sets at 7:30 in southeast), RIGEL (Orion), PROCYON (the Dog), BETELGEUSE (Orion), BETA CENTAURI (Crux), ALDEBARAN (in Taurus, just off the map, sets in the west at 7 p.m.), ACRUX (Southern Cross in Crux), ANTARES (Scorpius), SPICA (Virgo), POLLUX (Gemini), MIMOSA (Crux), and REGULUS (Leo).  Visit www.astronomyintanzania.or.tz for more information.


The best views of the International Space station come at the beginning of June.  On June 1, it rises to 45 degree elevation in northwest rising at 7:20 pm from southwest moving northwest and dropping down the north northeast horizon at 7:27 pm.  On June 2, it will rise just after sunset at 6:31 pm so will be more of a challenge to observe.  It will rise to more than 60 degrees in southeast and sets in northeast at 6:38 pm. Visit the Heavens Above website http://heavens-above.com for more satellites and exact times after entering your location.