Mississauga Centre RASC

104th Meeting

                                                         Members’ Night          

Day:                Friday April 25, 2008

Chair:               Randy Attwood

Speakers:          Roy Swanson

                         William Callahan

                         Randy Attwood   

A Quick Romp Through the Drake Equation

Roy Swanson discussed the Drake Equation formulated by Frank Drake.  This equation takes into account the various factors which determine how many communicating civilizations there are in the galaxy, where N = N*f_pn_ef_l fifcf_L, or the number of habitable stars times the fractions those that have planets, number of planets capable of sustaining life, the fractions where life evolves, where it is intelligent and communicates and the fraction of the plant’s lifetime in which the civilization does communicate.  The real value of the Drake equation is not the answer but the questions that are asked.  Roy pointed out websites where the user can calculate the answer by entering values for the terms.  Issues to consider are the habitability zone around a star, the metalicity of different stars, the finite lifetime of a star.  As an example of poor habitability, globular cluster stars would be exposed to life-killing supernovas.  

Into the Eye of the Storm, Orbital Mechanics and New Horizons

William Callahan revisited discussions in previous meetings about the New Horizons Mission to Pluto and the reason why it was launched in December rather that in June.  Using the formula esc vel = √2GM/r, and knowing that we are trying to escape from the Sun not the Earth, and considering that the maximum gravimetric potential energy and minimal kinetic energy occurs in July whereas the opposite is the case in January, he calculated the escape velocity as 42.5 x 10³ m/sec and total change in velocity as 12.2 x 10³ m/sec in December, and 41.8 x 10³ m/sec and 12.5 x 10³ m/sec for the same parameters in June.  He concluded that there is a small but definite advantage of 300 m/sec by using a December rather than June launch.  Therefore the increased speed in perihelion outweighs the importance of the distance from the Sun.  New Horizons left at its time, however because it needed a gravity assist from Jupiter and it had to approach Jupiter from a specific direction. 

GA June promotional video, Astronomy Day, NASA video

Randy Atwood, one of the organizers of the general Assembly of the RASC in June 2008, showed the promotional video for the GA.  He then spoke about the upcoming Astronomy Day on May 10 which will take place at the same time as the Science rendezvous at UTM, as well as an event at the Mississauga Library in the evening.  

A video on the 50^th anniversary of NASA with Steven Hawking and his daughter was then shown.  They discussed why we should go into space.  They spoke about the  feasibility of colonizing Mars and the Moon, the probability of life and intelligent life in the universe, the moons of Mars as potential colonies, and the education of children and encouraging them to become scientists and astronauts.

The Sky for May

Roy Swanson discussed the meteor showers including the Eta Aquarids; asterisms such as the Big Dipper which are parts of constellations, Scorpius which is a full constellation, and very large asterisms like the Summer triangle made up of several constellations.  He pointed out that Jupiter is visible in the morning sky, Mars is moving from Gemini to Cancer and into the Beehive cluster. 

 Submitted by Chris Malicki, Secretary  Chris Malicki, Secretary                               back to Miss Centre. meeting reports page
Mississauga Centre RASC