JUNE NIGHT SKIES OVER TANZANIA

CLICK ON MAP FOR LARGER VIEW

The astronomical event of the century, the Transit of Venus, was successfully marked in Tanzania with clear observations of the end of the transit on early morning of 6^th June with live coverage of the event from Coco Beach, Dar es Salaam. It was the most publicized astronomy event around the world and helped young students understand how the distance to the Sun was first calculated. For the first times since planets were discovered around other stars, scientists were able to fine tune their sensors and measure accurately the exact amount of light that is blocked when just a tiny dot comes across the face of the Sun. They will now be able to find far more exoplanets than the 400 or so that they have found up to now.

The night sky is now a bit duller with brilliant Evening Star, Venus, gone from the skies. However, after meeting up with the Sun on June 6, the planet has slowly shifted away from the Sun’s disk and now it can already be seen in the East as a Morning Star at dawn. During the next six months, it will be seen higher in the skies as the days go by. It will then fall back towards the horizon by January next year. Through a telescope, it has a crescent shape, just as it had in the evening skies a few weeks ago. Venus is set to make a close approach to Jupiter in the dawn skies by the end of this month where it will form a beautiful triplet with a crescent Moon on 15^th July.

Saturn is the most beautiful planet to watch in the evening skies and appears exactly overhead at 8 pm. It is not too bright so you will have to distinguish it from other stars by looking for a steady point of light that does not twinkle. The planetary movement of Saturn is quite noticeable if you follow the change in its position over several weeks as compared to the nearby bright star, Spica in Virgo (the Virgin). Through a telescope, you will see its elegant set of flat rings tilted sufficiently for us to see its shape clearly.

Mars is moving farther away from us in its orbit around the Sun and hence appears dimmer as the days go by, but is still bright enough to be seen easily as a red point with steadily shining light. It is also moving slowly away from it nearby constellation Leo (the Lion) approaching Saturn in the sky since Mars moves much faster in its orbit compared with Saturn. Mars is set to make a closest approach to Saturn on August 8. It is useful to follow the movement of Mars to appreciate that planets move, while stars do not change their relative positions, even over thousands of years.

The Moon is New on June 19 and First Quarter on June 27, when it will be overhead at sunset and it will be in half shape. This is the best time to see the Moon through a telescope or binoculars because the shadows cast near the light-dark edge are long and sharp. This brings the craters clearly into view. Full Moon will be on July 3 and Last Quarter on July 11.

This month’s sky map shows us that we can see nearly 18 constellations and asterisms. To see all of them you will need to be well away from city or town lights, in rural areas, where there is no light pollution. Marked alphabetically from A to R these are, from south to north, then east to west: A – Sagittarius the archer, B – Scorpius, C – Ara the alter, D – Triangulum Australe, the southern triangle, and E – the famous Southern Cross continuously pointing south. F – is the False Cross, G – is Vela, the sail, H – is the zodiacal constellation of Libra the scales of justice and I – is the long Hydra the snake. J is Virgo the virgin while K – is Leo the Lion. L - is Cancer the crab while M – is Hercules, N – is Bootes the herdsman, and O – is the famous Big Dipper pointing north. P – is Ursa Major, the big bear while Q – is Draco the dragon. R – is the Little Dipper in Ursa Minor whose end star is the North Star but which we never see as it is below the horizon.

Among the bright stars marked ‘m’ to ‘s’ on the map are: ‘m’ – Alpha Centauri the closest star at a distance of 4.3 light years and ‘n’ – is Beta Centauri. ‘o’ - is red star Antares in the neck of Scorpius, ‘p’ – is Spica in Virgo while ‘q’ is the third brightest star Arcturus (the first and second brightest stars are respectively Sirius and Canopus will have set in the south west by 8 pm). ‘r’ – is Regulus in Leo while ‘s’ – is Procyon.

The full glory of the dense concentration of stars and dust can be seen in the Milky Way, which stretches across the southern skies from southwest to southeast containing the constellations or asterisms C, D, E, F, and G. It runs parallel to the zodiacal constellations A, B, H, J, K, and L. June 20 is the Solstice, when the Sun starts its journey back towards the Equator from its northernmost position of 23.5 degrees at the Tropic of Cancer. This day marks the beginning of northern summer and southern winter.

The International Space Station does not have any bright pass over the Tanzanian skies this month, but it is set to make a show at the beginning of July on 6 and 8. However, the Chinese space station, Tiangong, now under construction will be seen on June 3 as a clearly visible point of light that cross the sky from northwest horizon at 7:08 pm and will move toward southeast. It will disappear suddenly from view while still up in the southeast sky at 7:11 pm. Go to www.heavens-above.com for exact details after entering your location. Visit www.astronomyintanzania.or.tz for more astronomy information and details.

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