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Comet C/2012 S1 (ISON)

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Most of the pictures of Hale-Bopp were spectacular. This is not one of them. It is one I took from the bright night sky of San Francisco in April 1997

The most spectacular comet in living memory was bright, had multiple tails and remained visible with the naked eye  for over a year. Hale-Bopp decorated the Earth’s night sky between 1996 and 1997.

Discovery of another comet C/2012 S1 (ISON) announced this week, if current predictions turn out to be correct,   may exceed the spectacle even of Hale-Bopp.

The comet first photographed on 21st September by two Russian astronomers Vitali Nevski and Artyom Novichonok using the  0.4meter refelecting telescope of the International Scientific Optical Network (ISOC) was announced three days later.

The expectations of brightness and size sound too good to be true. Brighter than the full moon, visible in daylight and even a probability breaking up in to multiple smaller units as it approaches perihelion (closest point to the Sun). Predicting cometary orbits  has come a long way over the last couple of decades. Even if the predictions are out by 50%, iC/2012 S1 (ISON) still has the potential for a night sky spectacle of a lifetime.

Comet C/2012 S1 (ISON) will get close not only to Earth and Sun (0.012AU of the Sun at the end of  November 2013 and then to ~0.4AU from Earth at the beginning of January 2014) but also Mars! May be Curiosity will snap a few pictures too.

 

Perseid Meteor Shower 2010

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The Perseid meteor shower is widely accepted to be  the best in the bunch available throughout the year. With only the waxing crescent Moon setting early, 2010 is likely to be the  best for many years.

The Zenith Hourly Rate (ZHR) predicted to be between 70 and 100  but only in dark cloud free skies.  With luck we may even see some fireballs.

The shower is the result of the dust particles  left in the path of the Earth’s orbit by comet Swift Tuttle burning up as they hit the atmosphere at 40 miles per second. The radiant (the constellation of Perseus, just below and to the the left  of the “W” of Cassiopeia) reaches an altitude of 55 degrees  at about 3am on Friday 13th. But that’s just the peak. There is lots of activity a few days either side.