March Night Skies over Tanzania

March Night Skies over Tanzania

While we say goodbye to Jupiter in our evening skies this month, another very interesting planet, Saturn, makes its entry from early evening. Saturn is a gaseous giant with a unique ring system that makes a beautiful sight that can wow anybody when seen using even a small telescope. It will rise in the East around 8 pm, which will make it visible throughout the night until dawn.

On its way out of the evening skies, Jupiter pairs temporarily with Mercury in the western skies in the brightness of the setting sun. From March 13 to 16, these two planets, which are largest and smallest planets in our solar system, will shift closer together until they are closest on March 16, two degrees (i.e. two finger widths) apart. The pair will be visible at a height of about 15 degrees above the horizon at sunset.

Mercury is a fast moving tiny planet (300 of them would fit inside our earth, and 300,000 inside Jupiter!), orbiting close to the Sun. So it is always visible close to the horizon while the Sun is setting or rising. This makes it very difficult to make out in the bright glow of the sky at sunset or sunrise. Use the opportunity presented this month to “catch” Mercury by looking for it near the much brighter Jupiter. It is indeed a challenge worth taking.

On March 11 the Moon will be close to the Pleiades cluster of stars, also known as the “Seven Little Sisters”. All the stars in this constellation are close to each other, different from most stars that only appear close because of their closeness along our line of sight. In reality, most stars that appear close together are actually separated by enormous distances, with one star almost directly behind the other. The Pleiades cluster also contains nebulous dust and gas brought together by gravity, which provides nurseries for new stars. This makes the Pleiades cluster beautiful to view, both with the naked eye and through binoculars or a telescope.

This year’s vernal equinox is on March 21, when the Sun will be exactly overhead at noon at the equator. Hence, on this day, lengths of day and night are equal throughout the world. For most parts of Tanzania, the overhead sun at noon will come a few days earlier than March 12 since we are south of the equator, and the Sun’s apparent movement between December 21 and March 21 takes it from the south at Tropic of Capricorn towards the equator, passing Tanzanian latitudes on the way.

First Quarter Moon, which is the best time for viewing its craters through a telescope, will be on March 13. Full Moon is on March 19 which, contrary to expectations, is not a good time to make out features on the Moon, since sunlight strikes the moon directly along our line of sight. Hence, there will be no shadows to give contrast to the features. The Moon would also be extremely bright through a telescope, making it painful to view.

On March 19, the Moon comes the closest to Earth in 18 years, at a distance of 356,577 kilometres, compared to the normal close distance of 364,369 kilometres every lunar month. With a Full Moon on the same day, there will be an alignment of the Moon with the Earth and the Sun in a conjunction called a “syzygy”

The Milky Way continues to dominate the overhead skies in the early night skies of March. It stretches from the Southern Cross in the southeast horizon, up through Sirius (the Dog), between Orion (the Hunter) and Gemini (the Twins) in the overhead skies, descending to Taurus (the Bull), and ending in Perseus, in the northwest horizon. Leo (the Lion) fills the eastern sky, while the pointers Southern Cross in the south and Big Dipper in the north, rise early in the west and can be used to find the north-south direction after 9 p.m. Be careful not to confuse the False Cross with the real one!

The best days to watch the International Space Station (ISS) this month are March 15 and 17. On the 15^th, the ISS will be extremely bright as it rises from the North West at quarter to eight (7:46 pm) but will disappear suddenly from view when it enters the Earth’s shadow after about two minutes 50 degrees above the horizon. On the 17^th it again rises from the North West at around seven o’clock (7:02 pm) but this time it crosses the whole sky passing overhead, very close to Betelguese, the red giant star in Orion and close to the brightest star in the sky, Sirius, taking eight minutes to cross the whole sky.

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