Mississauga Centre RASC

118th Meeting

                                                      Members’ Night  

Day:                Friday December 12, 2008

Chair: John Boyd

Speakers:          Roy Swanson

Randy Atwood

Bob Anderson

` William Callahan

The Aggressive Terraforming of Venus, The Sky at Night

Roy Swanson suggested that Venus is the best planet for long term human habitation despite Steven Hawking’s lecture at NASA’s 50^th anniversary stating that we should go to Mars. Besides being small, Mars is far from the Sun. Venus is 0.7 AU from the Sun is 95% as wide as the Earth and has the same density. It was explored by the Soviet Venera spacecraft and US Mariner. The surface has volcanic features, tectonics , a surface atmospheric pressure of 90 times the Earth’s with sulphuric acid clouds.

He recommended using silo-like facilities for experimenting with Venus’ atmosphere and how to change it. There are over 20,000 different types of algae. A few of these could use Venusian “elements” (sulphuric acid) and release oxygen, water and nitrogen. A “designer algae” could then be sprayed onto the tops of clouds and release elements for life. The clouds with the algae then fall to the ground and are converted to graphite thus using up the large amounts of carbon dioxide. There is some uncertainty in this last process. Once we prove the ability of a candidate to do the job, we can calculate how long it would take – it turns out to be 20 to 50 years if we are lucky. The process is unmanned until Venus is ready for humans. Venus is a better choice than Mars which is like an overgrown Moon.

Roy spoke about the sky for December. The Full Moon has its closest approach since 1993 on December 12. At the solstice, the sun appears to stop in its north to south movement.

Constellation of the Month: Orion

Randy Attwood continued with the constellation of the month series by highlighting Orion. It is the brightest winter constellation, picturesque with colourful stars and a great nebula. Randy discussed the mythology of Orion and the surrounding constellations. Orion’s belt stars can by use as a guide to other stars. Betelgeuse in the north east shoulder is a red giant variable 650 light years away and a supernova candidate. Rigel in the southwest is a very bright blue giant 800 light years away. The belt stars and other stars were described. The famous great nebula in the belt of Orion contains the trapezium star cluster. Nearby is the dark Horsehead Nebula. An image of Orion taken by the Mars rover was shown and the Orionid meteor shower described.

Flame Nebula

Bob Anderson described his planetarium program and image of the Flame Nebula

Introduction to Eyepieces

William Callahan described the types and function of eyepieces. A telescope collects and focuses light and the eyepiece makes the light rays parallel magnifies the image. He described the barrel diameter, apparent field of view, field and eye lens, singlet, doublet and triplet. The Kellner has a 3 element design, doublet eye lens and a 40 degree apparent field making it good for a high focal ratio. The Orthoscopic is a 4 element design with low distortion and high contrast making it good for planetary observing. The Plossl is also a 4 element design with two doublets and low distortion and best all round eyepiece. William recommended the Superplossl, a 5 element design. The Erfle with a 5 or 6 element design and wide field is good in long focal lengths. The Nagler with 7 or more optical elements, has a high field of view and is popular with Schmidt-Cassegrains due to their large focal ratios and 80 to 100 degree apparent field of view.

Chris Malicki, Secretary