Whale Talk Astronomy – John Saunders

The Pale Blue Dot

1. At the moment, the hottest talk in Astronomy circles is the Cassini spacecraft in orbit round Saturn. As Saturn is side on to the Sun and therefore eclipsing the rings and its moons on the far side, amazing shadows are occurring hence amazing pictures are being relayed back to Earth.

The Cassini will continue to send back pictures well into 2010, thirteen years after its launch and six years since it reached Saturn.

The Cassini Spacecraft was launched from Cape Canaveral en-route for the planet Saturn on the 15th August 1997 at 4.43 a.m.

It had to travel in the opposite direction first to the planet Venus in order to use Venus’ gravity as a slingshot and thus gain speed in order to reach its eventual destination.

It then went round the Sun twice before returning to pass Earth, Mars and Jupiter en-route to Saturn. All of these ‘side-trips’ were for the spacecraft to gain more and more speed for the 1.2 billion km trip to the ringed planet.

This actual photograph with no colour enhancements was taken on 15 Sep 2006 as the Cassini spacecraft left Saturn’s rings as it travelled out to meet up with its largest moon Titan to release the Huygens probe which in turn landed on Titan after being detached from the spacecraft. Cassini was then turned by its operators back on Earth to look back at the Sunrise and take the picture you now see above.


An alternative picture you can show is the fantastic picture of Saturn’s tiny moon Pan seen in the Encke Gap between two of Saturn’s rings. Although it was discovered by the earlier Voyager programme, Cassini did a fly-by of Pan during its path through the Encke Gap.
2. According to a NASA report, water has been discovered on the surface of the Moon. No lakes have been found, but rather NASA’s Moon Mineralogy Mapper aboard India’s new Chandrayaan-1 lunar orbiter radios back that parts of the Moon’s surface absorb a very specific color of light identified previously only with water. Currently, scientists are trying to fit this with other facts about the Moon to figure out how much water is there, and even what form this water takes. Unfortunately, even the dampest scenarios leave our moon dryer than the driest of Earth’s deserts. Very soon, the new LCROSS satellite will release an impactor that will strike a permanently shadowed crater near the lunar South Pole to see if any hidden water or ice sprays free there.

However, in other Astronomy articles it seems that although there is a strong case for water being trapped at the Moon’s poles, the case is not yet proven.

In my humble opinion, over the years I have read articles that water can be found on the moon but nothing has come of these apparent discoveries. Therefore until the day that water is scooped into a container from the moon’s surface and transferred back to the spacecraft and the water can be tested, or swigged down with a nice malt whisky and ice or to let one’s toy rubber duck float in a moon water bath, I will remain on the fence..
On the 3 day period 24-26 September the Hermanus Astronomy Centre hosted guest presenter and psycho-historian Auke Slotegraaf.

His three talks were titled as follows:-
1. Thursday 24 Sept. – The fascinating lives of three early scientists – Tycho Brahe, Johannes Kepler and Galileo Galilei.
2. Friday 25 Sept. – Making and using the Southern Star Wheel. In brief – making your own Planisphere
See in the picture below of members below busy at work cutting and pasting.

3. Saturday 26th Sept at the Hermanus Magnetic Observatory Auke treated us to a specialized topic entitled: A deep sky observing workshop.

On the 22nd October HAC Committee member Steve Kleyn will tell us all about Sundials – their history and how to use them.

Lastly, and most importantly our plans for an Observatory above Hermanus is proceeding with vigour.

However, the BIG question for us is the need for sponsors to invest in the project. The very fact that the observatory will be a landmark in Hermanus forever must be a huge benefit to the town and to anyone who wishes to invest in this amazing project. We need to raise R1.7m in order to build the observatory and to furnish it. Anyone who may be interested in joining us as a sponsor would be most welcome.

I would refer readers to our fantastic website www.hermanusastronomy.co.za which gives all the details of the observatory plans and the Centres activities.

Alternatively contact John Saunders on 028 314 0543 or via e-mail – shearwater@hermanus.co.za


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