JUNE 21 IS NORTHERN SOLSTICE DAY

SOLSTISI YA KASKAZINI JUNI 21 

VENUS - CRESCENT MOON CONJUNCTION

The dawn of Wednesday from 4:30 AM on 21 June will provide a spectacular show of a crescent Moon that is very close to brilliant Venus.  The beautiful sight will be seen in the east, 40 degrees above the eastern horizon when the Sun rises.  

MKUTANO WA ZUHURA NA MWEZI HILALI

Alfajiri ya kesho, Jumatano tarehe 21 Juni, baada ya saa kumi na nusu utaweza kuona mkutano wa sayari ya Zuhura, inayowaka vikali sana kama nyota ya asubuhi, pamoja na hilali ya Mwezi.  Zitatoa madhari ya kukvutia sana katika anga ya mashariki, kiasi cha nyuzi 40 juu ya upeo wa mashariki Jua linapochomoza.

JUNE 30 IS ASTEROID DAY

MARS MERCURY SUN AND MOON IN MAY SKIES

Jupiter shines extremely brightly together with the brightest star Sirius shines in the sky in the overhead in the night skies, while the second brighte st star Canopus shines nearer the south.  However, the limelight is taken this month by Mars and Mercury which show movement in the skies.

Mars is nearing opposition on May 22 when it will be in a straight line alignment with Sun and Earth in between. At opposition the full face of the planet is lit by the Sun which is behind us at night.  At this time the planet rises at sunset and sets at sunrise with overhead positon at midnight.  Mara is also currently moving closer to Earth and will be closest to Earth on 30 May at 75 million kilometers so its angular size is biggest while its full face is lit by the Sun, hence Mars can be easily spotted as a bright red dot in the night.  Currently it is rising in the East at 8 pm positioned inside the mouth of Scorpio near its red star Antares and nearby extremely bright Jupiter.  You can differentiate between the two red objects by the way the star Antares twinkles while Mars shines with a steady light.  At opposition on May 22 it will rise at sunset just outside the Scorpio’s mouth well and noticeably away from the red Antares and Jupiter.   It has not been closest since 2003 and will not be seen as brightly until the next opposition in 2018.

Furthermore, Mars is undergoing retrograde (opposite) motion in the sky.  All celestial objects move from west to east as they shift day after day across the background stars.  You will have noticed that the Moon shifts day by day from West at new moon phase until it reaches full moon phase in the East after 15 days.  Currently Mars can be seen inside the mouth of Scorpio near the red star Antares and brilliant Jupiter.  By May 22 you will notice that its position will have shifted westwards in retrograde motion to outside Scorpio’s mouth and will continue to do so until it is well away from Scorpio by the end of June.  It will end its retrograde westward movement on June 29 and will then move eastwards resuming its normal movement into the mouth of Scorpio, past red Antares and brilliant Jupiter and further eastwards until the next cycle which will be in 2018.

Mercury will make its appearance during the day on May 9 when it will cross the face of the Sun from 2 pm to sunset.  This called a transit which occurs when an inner planet Mercury or Venus are exactly aligned in a straight line with the planet between the Sun and Earth.  Usually there is always a slight angle between the three objects hence transits do not occur frequently.  This is similar to what happens during a solar eclipse when the Moon comes between the Sun and Earth. Again this does not happen every month since there is a slight misalignment of the three object.

The last transit of Mercury was in November 2006 while the next Mercury transit will be in November 2019.  Venus last transited the Sun in June 2012 and the next Venus transit will not occur until after more than a century in 2117.  Historically transits were used to determine the distance from the Sun to Earth by observing the transit simultaneously from different latitude positions.  The paths the planet across the face of the Sun will be different at different latitudes and from this the distance from Sun to Earth can be determined. 

Transits can be seen by projecting the image of the Sun through a telescope or a pinhole onto a white screen that has been shaded from surrounding light so that you can make out the tiny dot as it crosses the image of the face of the Sun.  IT IS DANGEROUS TO LOOK AT THE SUN DIRECTLY. You can time the moments of first contact of Mercury with the Sun on May 9 expected at 14:12:11, as well as the path of Mercury across the Sun and share your measurements with other enthusiasts on the internet and combine those measurements to get your own determination of the distance of Sun from Earth.

You should also prepare yourself for the major event of the Annular Solar Eclipse that will occur on September 1 this year, centered over southern Tanzania and visible across the whole of Tanzania with more than 90 percent of the Sun covered.  It will also be visible across almost the entire African continent with coverage decreasing towards north and south of Africa.  The central path of the eclipse will cross southern Tanzania from Katavi to Mbeya to Ruvuma and in an approximately 100 kilometer-wide path the Sun will be covered by the Moon such that it will leave a thin bright ring around the edge of the Sun for about three minutes.  The rest of Tanzania will witness more than 90 percent of the Sun being covered and will see a thin crescent shape of the Sun.  The whole eclipse event from beginning to end will last from 10 am to 2 pm.  You will need to use solar viewers to view the eclipse safely.  People from across the country and across the world will be coming to Rujewa, about 100 km from Mbeya, is most ideally located to be within the central path of the eclipse where a ring can be seen and the weather is expected to be clear to provide good viewing conditions. Scientists will set up equipment to observe the eclipse and its effects on the atmosphere and the surrounding.  Do not miss this opportunity to see this unique event in Tanzania.

CLICK ON MAP FOR LARGER PICTURE

Among the constellations to look out for are the Southern Cross in the south, whose long diagonal points towards the South.  Nearby the Southern Cross are the pair of pointers that point towards the Southern Cross.  The lower star of the pair is Alpha Centauri, the nearest star to us though its light takes four years to reach us.  Scientists are now attempting to shoot micro-spacecrafts towards this star hoping to make contact with other life that may be living in planets that revolve around that star.

Other constellations of interest is the Big Dipper with the shape of a frying pan whose side stars point towards the north direction.  Among the recognizable zodiacal constellations that run from west to east are Gemini, Leo, Virgo and Scorpio. The Milky Way contains a thick collection of stars and interstellar dust is seen towards the south from south west horizon to south east and contains the Cannis Major constellation which has the brightest star Sirius. Other constellations within the Milky Way are the Southern Cross, Scorpio and Saggitarius which is the direction towards the center of our Milky Way galaxy.

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LINE UP OF PLANETS IN FEBRUARY NIGHT SKIES OVER TANZANIA

Moon close to 5 visible planets in Dawn Skies

(press here for skymap with positions of Moon and planets)

2016 ASTRONOMY EVENTS FOR TANZANIA

MWEZI JIRANI NA SAYARI TANO ALFAJIRI

January 2016 Night Skies over Tanzania and the Year Ahead

We begin the year 2016 with high expectations of using the opportunity of an upcoming major solar eclipse event this year on 1st September.  An annular solar eclipse will be centered over Tanzania with the mid-eclipse path starting in the Atlantic, then cutting across central Africa from Gabon, through the two Congos and into Tanzania from Katavi in the west through Sumbawanga, Mbeya, Songea, Tunduru, Masasi and crossing out across the Ruvuma into northern corner of Mozambique and ending in Madagascar.

It is one the major events for us since the eclipse is centered over Tanzania, hence the whole country will witness a huge decrease in brightness of the Sun.  It occurs during mid-day from 9 am to 3 pm so the whole population, including school children will witness the event and be amazed by the power of nature and wonder about our Universe and get a scientific understanding of how nature works.  Within the central path at maximum eclipse the Sun will take the shape of a ring when seen through eclipse viewers.  Hence this eclipse is an Annular Solar Eclipse.  The rest of the country will experience a major partial eclipse where more than 80% of the Sun will be covered up and will look like a thick crescent when viewed through eclipse viewers.

In fact almost the whole of Africa from extreme north to extreme south will experience some partial eclipse and since it occurs during a suitable time for schools and public to participate in observations is being followed by African astronomers to exploit the event to attract students and public to science.  Prepare yourself by making sure you understand how eclipses occur and be able to imagine that the Moon is able to cover almost the entire Sun.  This happens because the size of the Moon, though small, seen as exactly the same as that of the much bigger Sun since the Sun is as much farther away as bigger than the Moon.  Hence when viewed from Earth the Moon and Sun both appear exactly the same size.  However this time, the Moon is farther away from us hence has a just slightly smaller apparent diameter than the Sun, hence will create the annulus or ring around the edge of the Sun.  Mark your calendar for various activities in preparation for the eclipse.

There will be three other eclipses one solar (March 9) and two lunar (March 23 and Sept 16), but they will not be visible since the second solar eclipse and one of the lunar eclipses occur well away from Tanzania so cannot be seen and one of the lunar eclipses (that of 16th September, just two week after the major solar eclipse), though it occurs above Tanzania we will not see any shadow since it is a penumbral eclipse in which only a very light shadow will cover us. 

All the major visible planets have deserted our skies since October last year when we last saw Venus in the evening skies.  However they are all set to come back to the evening skies in the coming months with Jupiter making a late night start from February and Mars and Saturn in April.  Jupiter is at opposition (brightest, rising in the east while the Sun sets in the west) on March 8 and hence can be seen in the sky throughout the night from sunset to sunrise of the following day. Mars will be at opposition on May 22, while Saturn will be in opposition on June 3 both rising in the east when the sun is setting in the west.  Venus makes its entry into the evening skies from July.  Fast moving Mercury jumps in and out of morning and night skies several times during the year but does not rise more than 25 degrees above the horizon hence always a challenge and exciting to see.  It will be at highest evening elevation of 20 degrees above the horizon at sunset on April 18.

For detailed listing of all the events that we will witness in Tanzania during the year, visit this website regularly to get updates on the events.

This is a month when the our southern skies come alive with dense collections of stars, nebulae and galaxies since the densest potions of our Milky Way enters our skies. The Orion constellation, seen from our skies as a big rectangle crossed with three diagonal stars, is the most recognizable constellation for the next five months as it shifts from east to west. From March, the Southern cross is easily identified also. The brightest stars brightest stars in the whole sky, Sirius and Canopus are accompanied by Capella, Rigel, Procyon, Achernar, Beltelgeuse, Aldebaran. These are among the top ten brightest stars in the sky, so go out and know your stars. 

The Milky Way contains a dense collection of stars and interstellar dust and nebulae stretching across the sky from the southeast across the sky to the north, grazing Sirius, Orion, Taurus and finally enclosing Perseus and Cassiopeia in the north. Three visible galaxies can be seen in the early night sky for the next few months. Two of these, the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are members of our local group with our Milky Way galaxy. Only southern observes can see the two Magellanic Cloud galaxies since they are close to the South Pole. They both have irregular shapes and cover a wide area of the sky with more than 4 to 5 degrees of angular width. LMC lies between Canopus and the South Pole and can best be viewed after 9 p.m. The SMC (3½ deg across) lies similarly between Achernar and the South. These two galaxies are about 50,000 light years away from us. The Andromeda galaxy can be seen in the north above Cassiopeia. It is more than 2 million light years away from us and can be seen as a fuzzy patch of light, making it the farthest object seen with the naked eyes.

The International Space Station (ISS) will show a spectacular crossing across the night sky on January 23, Saturday, from 8 pm and will cut across the sky from southwest at 8:04 pm rising majestically as a brilliant star moving slowly across the night sky towards northeast.  However, while it is still in the sky, it will suddenly disappear when it reached the corner of Orion constellation.  It disappears suddenly since it will have entered the Earth’s shadow and sunlight can no longer be reflected from its surface.  It is quite dramatic disappearance of a brilliant object so it is worth enjoying the ride as well as its abrupt end in mid skies. For specific times for your own location visit www.heavens-above.com and enter your coordinates.

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November Night Skies over Tanzania

October Night Skies Over Tanzania

SIKU ZA KUPOTEA VIVULI HAPA TANZANIA

Zero Shadow Days in Tanzania

SUPER BLOOD MOON TOTAL LUNAR ECLIPSE BEFORE SUNRISE ON MONDAY 28 SEPTEMBER

Kupatwa Kamilifu kwa Mwezi Alfajiri Jumatatu Septemba 28

Baada ya kupatwa kwa Jua hivi karibuni tarehe 13 Septemba,tukio ambalo sisi hapa Taznania hatukubahatika kushuhudia, Mwezi sasa unasogea siku hadi siku na utakamilisha nusu mzunguko siku ya Jumatatu alfajiri ya Septemba 28 na kuwa mstari mmoja tena na Dunia na Jua katika umbo la Mwezi Mpevu.

Siku hiyo ya Jumatatu alfajir, Dunia itakuwa kati ya Mwezi na Jua hivyo kivuli kikubwa cha Dunia kitapiga Mwezini na kusababisha Mwezi kupatwa kamilifu.  Kivuli cha Dunia ni kikubwa sana kuliko Mwezi kwa hiyo tukio la kupatwa Mwezi huonekana kwa muda mrefu zaidi ya saa moja.   Pia tukio hili huonwa na watu wote Duniani ambao wako upande wa usiku wakati tukio linaendelea angani.

Kuanzia saa 10:07 alfajiri siku ya Jumatatu tarehe 28 Septemba, kivuli kizito cha Dunia kitaanza kupanda juu ya uso wa Mwezi Mpevu na kusogea pole pole kujaza hadi kufunika sura nzima ya Mwezi, saa 11:11.  Huu ndiyo mwanzo wa kupatwa kikamilifu kwa Mwezi na utaendelea kuwa hivyo hadi Mwezi utakapo zama chini ya upeo wa magharibi saa 12:20.   

Mwezi utakapoanza kupatwa saa 10:07 utakuwa juu kiasi cha kutosha, cha nyuzi 30 juu ya upeo wa magharibi, kwa hiyo utaonekana vizuri katika giza la alfajiri kabla ya Jua kuchomoza.  Kutakuwa na masaa mawili hivi ya kufaidi mandhari ya ajabu angani wakati Mwezi utageuka rangi na kuwa mwekundu baada ya kufunikwa kikamilifu na kivuli cha Dunia.

The partial solar eclipse of 13 September which was visible in South Africa but not Tanzania is now followed two weeks later with a total lunar eclipse that will be visible to us before dawn on Monday September 28. 

Eclipses are caused by shadows cast when the Sun is lies on an exact straight line with Earth and Moon.  During a solar eclipse the Moon is in between so we see its shadow as having eclipsed the Sun. The night side of the Moon is facing us so only during New Moon can we get a solar eclipse.

During this September 13 solar eclipse, the Moon covered only about 42 percent of the Sun when it was viewed at the southernmost tip of Africa during this September 13 eclipse.  

During a total solar eclipse the Moon is able to cover the full disc of the Sun because the size of Moon and Sun are almost exactly the same.  It is just a coincidence of nature that the angular size of Sun and Moon are exactly the same (1/2 degree) because the Moon is moving ever so slightly away from us every day by about 4 cm per year so at this particular time in the life of our Earth the Moon has exactly the same size as Sun and hence can cover the Sun completely and cause a total solar eclipse. 

Having just caused a solar eclipse on 13th September, since the orbits of the solar system lie on a flat plane, the Moon is still is in alignment with Earth and Sun to form an exact straight line which results in a lunar eclipse.  Hence lunar eclipses occur two weeks after a solar eclipse during Full Moon with the Earth between the Sun and the Moon, causing the Earth’s shadow to fall directly on to the Moon. The Earth’s large size casts a large shadow three times larger than the size of the moon.  Hence lunar eclipses last longer and are seen by everyone who are on the night side when a lunar eclipse occurs. 

During this Monday September 28 dawn lunar eclipse, we will be able to see the beginning of the eclipse at 04:07 AM when the Moon will be 30 degrees above the western horizon with the Earth’s shadow edging on to the Moon from its upper right edge.  A black shadow will gradually slide over the face of the Moon which will be covered up by 05:11 AM by which time the Moon will be lower in the west, 15 degrees above the horizon. 

At 05:47 AM the Moon will be deepest within the Earth’s shadow the Moon darkens to its maximum amount.  However by that time the Moon will be very low, only 6 degrees above the west horizon so we may get lucky if there are no horizon clouds. We cannot see any further eclipse beyond that because the Moon will have set below the west horizon and the Sun will have risen to bring in the Monday morning at 6:20 AM.  Observers in the west of Tanzania in Kigoma and Bukoba will see a little more of the full eclipse than those in Dar es Salaam and Zanzibar.  The whole period of the eclipse, including the invisible penumbral parts, lasts from 03:11 AM to 08:23 AM. 

Once the Moon is fully covered after 05:11 AM, the colour of the Moon becomes bright red or brown and is called Blood Moon.  The colour arises from the light that is bent or refracted when it passes through the Earth’s atmosphere and blue light is deviated away while only red light remains.  This red light that has passed through the Earth’s atmosphere bends into the Earth’s shadow that falls on the Moon, giving it a red colour called the Blood Moon. 

The colour of the Moon during a total phase of the eclipse is a good indicator of the pollution in our atmosphere.  A clean atmosphere produces brilliant brown or deep orange colours while a polluted atmosphere produces a grey colour.  Watch out the colour of the Moon during this eclipse.  The Djon scale allows you to give a value to the type of colour of the Moon during the total phase of the lunar eclipse. Zero is assigned to a grey almost invisible Moon while 4 is assigned when the Moon is vivid deep orange or red.  Estimate the Djon value when you watch this eclipse and we can collect it for submission to a database.

This Monday’s total lunar eclipse is even more significant because the Moon will appear much lager than normal since it is at its closest point in its orbit around Earth.  Such a Moon is called a supermoon so this lunar eclipse is a Super Blood Moon lunar eclipse.  The next such occurance will not be until 2044 so do not miss this one on Monday before sunrise.

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September Night Skies over Tanzania - Two Eclipses and the Dhul-Hajj Crescent

Our majestic Moon determines the fate of three major events this month, a Partial Solar Eclipse, Idd ul Adha/Hajj, and a Total Lunar Eclipse.

 The first event, a partial solar eclipse occurs over the Antarctic on September 13.  A solar eclipse occurs when the Moon aligns exactly between the Earth and the Sun hence cutting off all or part of the sunlight.  Though this eclipse will not be visible from Tanzania, solar eclipses generate great interest among scientist for their ability to provide a natural laboratory to measure effects when a considerable portion of the Sun’s energy is suddenly cut off.  The author will be joining an enthusiastic eclipse team led by Professor Jay Pasachoff, a renowned solar eclipse scientist, to observe the maximum eclipse from the southernmost tip of Africa at Cape Agulhas 250 kilometers southeast of Cape Town. This will be Prof Pasachoff’s 62nd solar eclipse expedition, which the author hopes to use to gain useful experiences to conduct similar eclipse measurements during our own major annular solar eclipse next year, on 1st September, 2016, that will be centered over southern Tanzania

Solar eclipses occur when the Moon is in alignment with Earth and Sun.  This marks the exact moment of New Moon during which the night side of the Moon is facing us, hence we cannot seen the New Moon. Islamic months follow the lunar cycle following observations of the First Crescent, which can only be seen when the Moon has moved sufficiently away from its alignment with Earth and Sun.  This allows a small portion of the sunlit portion of the Moon to become visible to observers on Earth.  Such a condition usually requires the Moon to be al least 10 degrees away from the Sun-Earth line, hence the First Crescent this month cannot be seen on 13th. By the following day, 14th, a thin (1.5%) crescent will be 13 degrees above the horizon and can be visible if the sky is clear in the west.  This year’s First Crescent will mark the beginning of the month of Dhul Hajj, ten days after which is marked the Idd ul Hajj after the completion of the pilgrimage to Macca of millions of Muslims from around the world.  Since the Antarctic solar eclipse occurs on 13th September, the First Crescent will be expected to be visible the next day, 14 September and counting 10 days after that, the Idd ul Hajj can be expected to be celebrated on 24 September, 2015.

The third event determined by the Moon is the September 28 Total Lunar Eclipse during Full Moon. Having just caused a solar eclipse on 13th September, the magnificent Moon will still be in similar Earth-Sun alignment and will result in a lunar eclipse.  Lunar eclipses generally follow 15 days after the a solar eclipse because during this time the Moon shifts moves in its orbit to be in a Full Moon position when the Earth comes  between the Sun and the Moon, causing the Earth’s shadow to fall directly on to the Moon. This causes the lunar eclipse.  This month’s Total Lunar Eclipse will be visible in Tanzania and will be seen in the west, just before dawn/sunrise of Monday 28 September when the Moon is setting below the western horizon.  The partial phase will begin at 04:07 AM when the Moon will be 30 degrees above the western horizon with the Earth’s shadow starting from the upper edge of the Moon.  A black shadow will gradually slide over the face of the Moon which will be covered up by 05:11 AM by which time the Moon will be lower in the west, 15 degrees above the horizon. 

Once the Moon is fully covered its colour changes to brown or orange due to refracted light  from the Earth’s atmosphere.  The colour in fact can show us how much pollution is there in our Earth’s atmosphere, with a clean atmosphere producing brilliant brown or orange colours while a polluted atmosphere produces a greying colour.  Watch out the colour of the Moon during this eclipse.  If the horizon sky is not cloudy, we can expect to see the maximum darkness at 05:47 AM when the Moon will be very low, only 6 degrees above the west horizon.  We will not be able to see the remaining progress of the eclipse because the Moon will have set below the horizon and the Sun will have risen by 6:20 AM.  Observers in the west of Tanzania in Kigoma and Bukoba will see a little more of the full eclipse than those in Dar es Salaam and Zanzibar.  The whole period of the eclipse including the invisible penumbral parts occur between 03:11 AM and 08:23 AM.

The next total lunar eclipse will not occur over Tanzania for another three years until 27 July 2018 so better make the most of this opportunity to wake up very early on to behold the golden Moon. Check out more descriptions of eclipses on on http://www.astronomyintanzania.or.tz

We are once again upon the equinox with 23rd September as the day of Equinox.  The length of day and night will be exactly equal (12 hours) throughout the world.  The Sun will be exactly overhead at midday for places on the equator. 

For us in Tanzania who are between 2 and 11 degrees south of the equator the Sun is overhead twice each year, the first before the March equinox, between February 23 and March 18 and the second between September 26 and October 22 after the September equinox.  It is interesting to look out for the exactly overhead sun during this period because shadows of all vertical objects disappear below the object and you cannot see them. If you stand in the midday Sun on these two days you will not be able to see your own shadow.  Go out and find out which day during the September 26 and October 22 period and find out on which day your shadow disappears at midday.  Learn more about the zero shadow day from http://planetcalc.com/1875/ and http://www.iiap.res.in/iya09/VPwkshop/talks/RugvedPund.pdf

Among the planets we shall see a good array of them in the evening and pre-dawn skies. Saturn continues to occupy a high position, close to the tentacles of Scorpio, 60 degrees above the western horizon at sunset and visible until 10 pm lower in the west.  A beautifully crescent Moon will be close to Saturn on 18 and  19 September with the crescent cradling the Saturn on the first day and then moving past the planet on the other side on the second.  By 20th the Moon will be half shape which is ideal for viewing its craters through a telescope along its day/night line where long shadows vividly highlight the depth of the craters.

Mercury is still high at 20 degrees above the west horizon at sunset and is fast moving down and will be lost in the Sun’s glare by 25th.  On 15th September Mercury will be in a right angled triangle with a beautifully thin crescent Moon to its right and above them will be Spica the bright star of Virgo. Through a telescope, Mercury has a crescent shape now.

All the other visible planets are on the dawn/sunrise side towards the East. Venus shines brightly, dominating the morning sky 30 degrees above the east horizon at sunrise.  Jupiter will become visible and shine brightly with Venus from 9th September onwards.  On 10 September a thin crescent Moon will be close to Venus, while on 11th the crescent will be between Venus and Jupiter while on 12 September the crescent Moon will be close to Jupiter.

Jupiter is shifting up in the sky and by 25th of next month Venus and Jupiter join up in the eastern sky at 40 degrees elevation to be extremely close within one degree.

The Milky Way stretches as a band of numerous stars across the middle of the evening sky, passing through the Southern Cross in the southwest, through Sagittarius overhead, to Cygnus in the northeast.  The portion of the Milky Way close to Sagittarius appears as a cloud that is not a real cloud but nebulae of dense interstellar matter that is hiding from our view a powerhouse that is a supermassive blackhole at the center of the Milky Way galaxy.

The Scorpio constellation can be clearly identified by its namesake the scorpion and can be seen high in the western sky.  The eastern sky has two “birds”; one to the northeast, where you will see the Cygnus with its body and wings making a wide cross, while in the southeast you will see the smaller bird Grus with its head twisted sideways and its brightest star Alnair (J).

Try to become familiar with the brightest stars by their names and relative locations. Eight of the top twenty brightest stars in the sky are visible in our evening skies.  The stars marked A to H are listed here with their names and its rank in brightness.  A – Formalhaut (18th), B – Altair (12th), C – Deneb (19th), D – Vega (5th), E – Antares (16th), F – Alpha Centauri (4th), G – Arcturus (3th), H – Spica (15th).  The other less brighter stars are: Alnair (J), Peacock (K), Kaus (L), Girtab (M), Shaula (N), Atria (P), and Hadar or Beta Centauri (R).  The asterism marked S on the map is the Square of Pegasus, which is quite noticeable and can guide you to Andromeda Galaxy marked T on the map and rising in the north east at 8 pm.  This galaxy is 2 million light years away and can be seen as an oval cloudy patch in dark skies, making it the most distant object that can be seen by our eyes directly without a telescope. Star with brightest stars A to H and use those to find your way around the sky.

There will be an opportunity to see the International Space Station over three days from 26 to 28 September but the best view will be on 28th when it will cut across the sky from 6:31 PM to 6:40 PM moving from southwest to northeast horizons.  The Sun will have just set at 6:18 PM so the sky will be still bright but the ISS is bright enough to be seen in the twilight.

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Planet string in JUNE NIGHT SKIES over Tanzania

MARCH VIEWS OF International Space Station (ISS)

GROUND PATHS OF ISS

Eclipses, Meteors, Planets and Moon, 2015

The following is a summary of interesting astronomical events during this year 2015 that can be observed by the public without the need of a telescope.

The events are described for positions in the sky and the times for viewers in Tanzania, or East Africa.   You may read about some of these events in international media but some of these are not seen from Tanzania and the timings can be different.

The events are chronologically arranged by dates that they occur.

Eclipses:

Glossary:

Ø  Solar eclipses occur when our view of the Sun is blocked by the Moon during the daytime causing a small shadow of Moon to fall on Earth. The Moon is in between the Earth and the Sun.

Ø  Lunar eclipses occur when the large shadow of Earth falls on the Moon.  The Earth is in between the Sun and the Moon.

Ø  Total eclipses occur when the shadow is dark, called umbra.

Ø  Partial eclipses occur when the shadow is not completely dark (called penumbra) since some light falls in the shadow area.

Ø  Exciting Note: Next year 2016, an annular solar eclipse passes through a 100 kilometer path across southern Tanzania on Sept 1, 2016. The whole of Tanzania will experience nearly 90 percent of the Sun being covered.

·         Total Solar Eclipse, 20 Mar, North Pole, None visible in Tanzania

·         Total Lunar Eclipse, 04 Apr, Pacific Ocean, None visible in Tanzania

·         Partial Solar Eclipse, 13 Sep, South Pole, None visible in Tanzania

·         Total Lunar Eclipse, 28 Sep, Atlantic Ocean, Partial eclipse visible in Tanzania

Meteor Showers:

Glossary:

Ø  Meteors are light streaks in the night sky that look like a shooting star.  The light is emitted by burning in the atmosphere of tiny dust grains from coming from space. Sometimes larger particles can strike the atmosphere and the light glows much more brightly or even explodes known as bolides.

Ø  Meteor showers are formed when high concentrations of dust from past comets trails and asteroids strike Earth at the same time causing many meteors in a short period.

·         Quadrantid, Weak, North, Jan 3-4, Big Dipper, Moon too bright

·         Lyrids, Weak, North, Apr 22-23, Cygnus, Vega(Alpha Lyrae) Moon too bright

·         Eta Aquarids, Strong-60 met/hr, Equator, May 5-6, Aquarius, no Moon so meteors can be detected

·         Delta Aquarids, Weak, near Equator, Jul 28-29, Fomalhaut-pegasus square, Moon too bright

·         Perseids, Strong- 60 met/hr, North, Aug 12-13, Perseus, No Moon so meteors can be detected

·         Draconids, Weak North Oct 8-9, Little Dipper, Moon too bright

·         Orinids, Weak, Equator, Oct 21-22, Orion, Moon sets early so meteors can be detected, (additional - Venus-Jupiter-Mars in morning sky)

·         Taurids, Weak, Equator, Nov 5-6, Taurus, Quarter Moon too bright in morning sky

·         Leonids, Ok, Equator, Nov 17-18, Leo, Quarter Moon sets early so meteors can be detected

·         Geminids, VeryStrong-120 met/hr, Equator, Dec 13-14, Gemini, Crescent Moon sets early so meteors can be detected

·         Ursida, Weak, North, Dec 22-23, Little Dipper, Moon too bright

Planets:

Glossary:

Ø  Planet opposition occurs when the full face of the planet is lit by sunlight with the planet on one side (east side) of Earth while the Sun is on the opposite side (west). So a brightly shining planet rises from the east at sunset.

Ø  Close approach of planets in the night sky occurs when their lines of sight as viewed from Earth are separated by very small angles.  Hence though they appear to be close to each other in the night sky, it does not mean that they are actually close to each other in space.  All planets are separated by millions of kilometers of space in their orbits around the Sun.

·         VENUS and MERCURY close, Jan 10, they will be seen close together 20 degrees above the west horizon just after sunset. Start watching from now up to mid-January as Mercury approaches Venus from below and comes closest on Jan 10 within one degree and then moves down again away from Venus.  Mercury is a faint point and can be a challenge to detect, while Venus will be bright. Venus will continue to rise in the sky in the following months rising to 40 degrees in June and then quickly coming down to the horizon by August.

·         JUPITER at opposition, Feb 7, brilliantly bright Jupiter will be seen rising in the east just as the sun sets in the west. It will remain in the evening night sky for the next six months moving gradually westwards.

·         VENUS and MARS close, Feb 21, they will be seen close together 20 degrees above the west horizon just after sunset. Start watching from mid-February up to the end of February as first Venus approaches Mars from below and comes closest on Feb 21 within half a degree and then moves up away from Mars.  Mars is a tiny red point while Venus will be very bright yellow.

·         Uranus and VENUS close, Mar 4, though Uranus cannot be seen easily since it is very faint, it can be seen with naked eyes only in darkest skies since it is just at the limit of naked eye visibility.  However this is an excellent opportunity for telescope observation of the planet (even through small telescopes) since it can be located within a tenth of a degree from Venus on Mar 4 so it can be easy to catch even in a small telescope. The pair will be 30 degrees above the horizon at sunset with Uranus approaching Venus from above coming closest to Venus within a tenth of a degree on Mar 4 and passing below on following days.

·         Uranus and MARS close, Mar 11, presents another opportunity to locate the faint Uranus through even a small telescope when it comes closest to Mars to within half a degree.  Mars is a faint red star and can be identified among the other stars.

·         SATURN at opposition, May 24, sharply shining Saturn will be seen rising in the east just as the sun sets in the west. It will remain in the evening night sky for the next six months moving gradually westwards.

·         JUPITER and VENUS close, Jun 30, two brilliant planets will shine as bright stars in the evening sky close together 40 degrees above the in the west soon after sunset. Start watching from mid-June to mid-July as Jupiter approaches Venus from above and comes closest on June 30 within half a degree and then moves down away from Venus. This will be an extremely noticeable event since many people will see two extremely bright objects close in the sky for more than a month.

·         JUPITER and MERCURY close, Aug 7, seen 15 degrees above the western horizon at sunset, with Venus 10 degrees to the left below the Jupiter-Mercury pair.

·         JUPITER and MARS close, Oct 18 they will be seen close together 30 degrees above the east horizon just before sunrise. Start watching from beginning of October to mid-October Jupiter first approaches Mars from below and comes closest on Oct 18 within quarter of a degree and then moves up away from Mars.  Mars is a tiny red point while Jupiter will be very bright white.

·         JUPITER and VENUS close, Oct 26, two extremely brilliant stars, Venus and Jupiter will be seen close together 40 degrees above the east horizon just before sunrise. Before sunrise they will be seen closer to the east horizon.  Start watching from mid-October up to the end of October as first Jupiter approaches Venus from below and comes closest on Oct 26 within half a degree and then moves up away from Venus. This will be an extremely noticeable event especially for early rises since they will be seeing two extremely bright objects in the sky for almost the whole of October.

·         VENUS and MARS close, Nov 3, they will be seen close together 45 degrees above the east horizon just before sunrise.  They will come closest to within half a degree as Mars approaches Venus from below and then moves up away from Venus.

·         VENUS and SATURN close, Jan 9 2016.  They will be seen 35 degrees above the western horizon at sunset and will come closest to each other within a tenth of a degree.

Moon:

Glossary:

Ø  Full Moon occurs when Moon is on one side (east) of Earth while Sun is on the opposite (west) side. Hence sunlight is striking the Moon full face and the full bright circle of Moon is seen in the east from sunset onwards.

Ø  New Moon occurs when Moon is viewed with Sun directly behind it hence dark (night) side of Moon is facing us and dark face is in the west horizon at sunset.

Ø  Crescent Moon occurs immediately after New Moon once some sunlight is able to strike the Moon but we see only a thin part of the lower side of the Moon. Crescent Moon are seen low in the west horizon at sunset or low in the east horizon at sunrise.

Ø  Half Moon occurs when we see the Moon as a half circle and is .  It is actually called First Quarter or Last Quarter since it occurs during first or last quarter of the Moon’s cycle around Earth.

Ø  Gibbous Moon is shaped like an oval and occurs between half Moon and Full Moon.

·         Full Moon, Jan 5

·         New Moon, Jan 20

·         Crescent Moon close to MERCURY Jan 21, will be seen 12 degrees above the western horizon at sunset with Moon 2 degrees below Mercury.

·         Crescent Moon close to VENUS and MARS Jan 22, will be seen 25 degrees above the western horizon at sunset with Moon in between Mars above and Venus below 10 degrees apart.

·         Crescent Moon close to MARS Jan 23, will be seen 40 degrees above the western horizon at sunset with Moon 2 degrees above Mars.

·         Full Moon, Feb 4

·         Full Moon close to JUPITER Feb 4, will be seen rising in the east horizon soon after sunset and will be visible throughout the night, slowly shifting westwards through the night

·         New Moon, Feb 19

·         Crescent Moon close to VENUS-MARS pair, Feb 20, will be seen 20 degrees above the western horizon at sunset with the planet pair 5 degrees above crescent Venus. The trio will slowly drop lower through the night and set after about an hour.

·         Almost full Moon close to JUPITER, Mar 3, will be seen rising above the east horizon at sunset and the pair will be seen slowly shifting westwards through the night.

·         Full Moon, Mar 5

·         New Moon, Mar 20

·         Crescent Moon between Venus and Mars, Mar 22, seen at 25 degrees above the western horizon at sunset, with Venus 5 degrees above and Mars 10 degrees below the crescent Moon. The trio will slowly drop lower through the night and set after a couple of hours.

·         Half Moon close to JUPITER, Mar 30, will be seen near the zenith from sunset, shifting westwards through the night.

·         Full Moon, Apr 4

·         New Moon, Apr 18

·         Crescent Moon close to VENUS, Apr 21, will be seen 35 degrees above the western horizon at sunset with Venus 10 degrees to the right of crescent Moon. The pair will slowly drop lower through the night and set after a few hours.

·         Half Moon close to JUPITER, Apr 26, will be seen near zenith 5 degrees apart with the pair shifting westwards through the night and set below the western horizon soon after midnight.

·         Full Moon, May 4

·         New Moon, May 18

·         Crescent Moon close to VENUS, May 21, seen 40 degrees above the western horizon at sunset.  The pair will slowly drop lower through the night and set after a few hours.

·         Half Moon close to JUPITER, May 23, 24 seen close to zenith overhead about 10 degrees apart.  They will shift slowly westwards and set before midnight.

·         Full Moon close to SATURN, Jun 1, with the pair rising above the eastern horizon at sunset. They are 2 degrees apart and shift westwards throughout the night.

·         Full Moon, Jun 2

·         New Moon, Jun 16

·         Crescent Moon between JUPITER-VENUS pair, Jun 20, seen 45 degrees above western horizon at sunset, with Moon 5 degrees apart from the planet pair. The trio will slowly drop lower through the night and set after a few hours.

·         Almost full Moon and SATURN close, Jun 28, seen half way up the eastern sky at sunset with the pair 5 degrees apart and shifting slowly westwards through the night.

·         Crescent Moon close to VENUS-JUPITER pair, Jul 18, seen 30 degrees above the western horizon at sunset forming a triangle 5 degrees apart.  The trio drops slowly, and sets below the horizon after a couple of hours.

·         Gibbous (oval) Moon close to SATURN, July 26, near zenith 65 degrees above eastern horizon at sunset.  The pair shifts slowly westwards and sets after midnight.

·         Full Moon, Jul 31

·         New Moon, Aug 14

·         Half Moon and SATURN close, Aug 22, seen close to zenith overhead two degrees apart.  The pair shifts slowly westwards through the night setting close to midnight.

·         Full Moon, Aug 29

·         New Moon, Sep 13

·         Half Moon and SATURN close, Sep 19, seen close to zenith overhead two degrees apart.  The pair shifts slowly westwards through the night setting close to midnight.

·         Full Moon, Sep 28

·         New Moon, Oct 13

·         Crescent Moon and SATURN close, Oct 16, seen 40 degrees above western horizon at sunset 2 degrees apart.  The pair sets slowly below the western horizon after a few hours.

·         Full Moon, Oct 27

·         New Moon, Nov 11

·         Crescent Moon and SATURN close, Nov 13, seen 20 degrees above western horizon at sunset with crescent 5 degrees above Saturn.  The pair sets after an hour.

·         Full Moon, Nov 26

·         New Moon, Dec 11

·         Full Moon, Dec 25

·         New Moon, Jan 10 2016

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Hazina Iliyofichika Mbozi, Kusini Tanzania