Mississauga Centre RASC

81st Meeting

                                                                                                 Members’ Night      

 

 

Day:                Friday March 23, 2007

 

Chair:                Randy Attwood

 

Speakers:          Randy Attwood                                                                                         

                          Ian McGregor

                         William Callahan

                         Chris Malicki 

                         Terry Hardman

                         Roy Swanson

                        

 

 

Finding Your way Around the Sky, An Introduction for Beginners

 

Randy Attwood described the rotating Earth, the celestial sphere, the horizon, the north celestial pole, apparent sky motion, the sky as a sphere, defined terms such as “zenith’, “altitude”, “azimuth”, “meridian”, and angular size.  He demonstrated the celestial equator, declinations and right ascension, the Big Dipper and Cassiopeia as a clock, the view of the sky from various latitudes on the Earth, seasonal changes, the ecliptic, tilt of the Earth’s axis and the cause of seasons. He showed the Sun’s course through the sky, the Moon’s path and 5 degree tilt to the ecliptic plane.

 

Observing Course

 

Ian McGregor is about to teach his 100th astronomy course to members of the Mississauga RASC. The observing course will involve both theoretical (looking down) and practical (looking up) aspects and will be based on the RASC certificate “Exploring the Universe” wherein one needs to see 55 of 110 objects in 6 categories.  The course is the start the upcoming Monday and will be run by Randy and Ian with an observing session with Bob Anderson.  Ian described last year’s course as a comparison.

 

Orbital Energy

 

Chris Malicki reminded the group about the argument at the  January 26, 2007 meeting as to whether it is energetically advantageous to launch the New Horizons space probe at Earth’s perihelion as opposed to aphelion.  He showed that the sum of the gravitational potential energy and kinetic energy of the earth is the same anywhere in its orbit.  Although the spacecraft would be moving faster at Earth’s perihelion speed it would also be in a deeper gravity well and as a result would have no energy advantage launching at perihelion or aphelion.

 

Observing at Saddington Park

 

William Callahan described the observing site of Saddington Park  on Lake Ontario.

 

Astronomy Day

 

Terry Hardman spoke about the upcoming Astronomy Day to be held at the Mississauga Central Library.   Randy spoke about organizing an active observing group and the need to have observing after meetings of the Mississauga Centre.

 

The Sky for April

 

Roy Swanson discussed sky happenings for April including planets especially Saturn, the plane of the ecliptic.

 

After the meeting, telescopes were set up in the parking lot for a session of informal observing.

 

 

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