Chairman’s Chat
Astronomically Exciting Times

This is one of the most exciting times to be involved in astronomy that I can remember. We have so much to look forward to in the coming months that I can hardly keep the balance between work and my hobby in check. My diary is crammed full of ASSA events and astronomical firsts.

By the time you read this, you will be in the throes of your final preparations for deciding the logistics of how you will spend the first and last time in your life watching our sister planet relentlessly charging across the face of our home star. I can unashamedly confess to sacrificing an income-generating work opportunity in favour of enjoying the complete 8 June Venus Transit. I guess it boils down to me finally practicing what I preach in my time management courses: place the big rocks (events) in your life first before adding the tiny grains of sand that make up our daily forgettable grind.

Then, on 11 June my personal baby begins its adventure at destination Saturn – the Cassini-Huygens Probe. I have been keeping tabs on this one since its launch on the back of a Titan IVB Centaur Rocket on 15 October 1997. Since then, I have been receiving email alerts from the JPL Cassini Probe web site on a regular basis. I recall my amusement in December 1997 when Greenpeace had a frothy about the probe’s close (12000km) gravity assist flyby of Earth due to it carrying a battery-load of power-generating plutonium. I also recall my concerns when receiving emails about malfunctioning equipment, late booster burns and communication glitches. The emails regarding the transit journey through the asteroid belt  read like a Agatha Christie on steroids;  the pursued brilliantly outwitted the pursuers.

Oh yes, June 11 and Cassini’s 2000km flyby of Saturn’s most distant Moon, Phoebe. What treasure-trove of photographs of this obscure and rocky outpost await? The craft is so close now that the high resolution camera cannot get the entire mother planet and its rings in one frame. 

Then, on July 1^st at 01:12 UT, Cassini will perform the critical Saturn Orbit Insertion burn sequence. The craft will perform the long-awaited ring plane crossing and  pass between the large but tenuous F- and G-ring gap. When this happens, the craft will be 158 500 km from Saturn, but it will be just one hour 52 minutes away from its closest approach to the gas giant – 18000km! Cassini will continue to coast above the rings for 1 hour and 44 minutes before its descent back through the ring plane.

Just a few hours before you awake to open your Christmas presents this year, the Huygens probe will separate from Cassini and begin its 22 day journey to the only atmosphere-enveloped moon in our solar system – Titan. Then, on 14 January 2005, the probe will begin its 2˝ hour descent to the mysterious surface of Titan, during which time we will receive 1100 images and a truck-load of data from five other instruments. What surface will Huygens land on: hard, rocky, sludge, a marsh of hydrocarbons … a sea of methane? There is no way of knowing for certain. This is exploration into a new world at its most exciting and unpredictable. 

This explorer is on its own and a very distant 1.4 billion kilometres away from help. One-way light travel time is 1 hour 20 minutes. If something goes awry, it’s probably going to be too late to help. I hold thumbs that JPL Mission Control have all their mathematical ducks aligned and that there will be no imperial-metric rivalry.  

So, what else do we have in store for you this year? The Swinburne Star Party, The Brass Monkey Star Party near Lady Grey, Excursion to Sutherland, Astronomy and Telescope Day at the Rosebank Rooftop Market … and the 2004 ASSA Symposium, hosted this year by the Johannesburg Centre.

My astronomical diary continues to creak and groan under the glorious burden.

Dave Gordon