November Night Skies over Tanzania

November Night Skies over Tanzania

By Dr. N. T. Jiwaji

ntjiwaji@yahoo.com

Science fiction may again become science fact following the recent discovery of shallow oceans below the icy crust of Jupiter’s moon Europa. It has long been believed that liquid salt-water oceans exist under the thick icy crust. Where there is water there is expected to be life. The chance of finding life is now increased because the Sun’s energy is more efficiently trapped in a shallow body of water.

The ice crust above the shallow water has been found to be made up of jumbled pieces of ice, and these can only form if convection currents in the shallow water below toss the ice broken up by Jupiter’s immense gravitational pull. The jumbled crust would be much weaker than the kilometres thick ice found in other areas of the moon. Such weakened areas would aid robotic probes to drill through to look for life in the shallow waters below.

Arthur C Clarke, the legendary science fiction writer predicted that in 2011 (this year!!) robot probes would drill through Europa’s crust and discover creatures living in the moon’s cold oceans. Though we may be off the mark by a few years, the chances of sending probes to Europa are more likely now, in spite of budget problems faced by Space Authorities.

Venus continues to shine brilliantly in the West while Jupiter shines similarly bright in the East. Since Jupiter in darker sky in the East, away from the setting Sun, it appears at first glance like an aeroplane about to land. I heard one person describe it like that but to his surprise it just stayed put and did not move!! Through a telescope, Venus is still a tiny dot that can appear oval since it is in a gibbous phase. Jupiter’s equatorial cloud belts appear as parallel stripes, and its four Galilean moons can be clearly seen changing positions within a couple of hours of viewing.

A day after the New Moon on November 25, a very pleasant scene awaits us in the western horizon skies soon after sunset. A thin newly-crescent Moon will be seen between Venus and Mercury on Saturday, November 26. The next day, a slightly thicker crescent Moon will be seen above brilliant Venus - a sight not worth missing. We hope the recent let up in the unseasonal rains will keep clouds away from the west to allow us to witness this unique sight.

Saturday and Sunday November 26 and 27 are good days to see Mercury through a telescope since it will be in a crescent phase. This occurs when Mercury’s orbit brings it closer to Earth and almost in line with the Sun. In the final days of November, the Moon will grow bigger, shift its position, and change its shape and will reach Jupiter on December 6 in a gibbous phase, just bigger than half.

The Andromeda galaxy, the farthest galaxy (at 2 million light-years away) that we can see with our naked eyes is close to the Square of Pegasus nearer to the northern horizon, while our nearest galaxy, (at half a million light-years), the South Megallanic Cloud, lies at the opposite end of the sky in the south, between Achernar and the south point. In relatively dark skies, both galaxies appear as fuzzy patches about 4 degrees across (4 fingers held at an arm’s length).

The bright stars this month that are worth knowing by name are: A) Fomalhaut, B) Altaír, C) Deneb in Cygnus (the northern bird), D) Vega, E) Achernar, and last, F) Aldebaran, which is in constellation Taurus, just rising in the east. These are all first magnitude stars. Algol in Perseus is a special star because it varies continuously in brightness approximately every three days.

The Milky Way band across the sky winds its way from southwest to northeast, straddling the western horizon so it does not cross the sky. Hence, this month most of the sky will appear to have rather few stars because it is well away from the bright band.