Mississauga Centre RASC

85th Meeting

                                                            Members’ Night       

                                                   

 

Day:                Friday May 25, 2007

 

Chair:                Vic Cooper

 

Speakers:          Vic Cooper

                          Randy Attwood 

                          Bob McCall 

                            Roy Swanson

                        

 

 

“The Universe”

 

Vic Cooper spoke about and recommended the book, “The Universe, the Definitive Guide”,  a pictoral volume about the solar system, stars, cosmology, constellations etc.

 

 

Chasing Earth Satellites 

 

Randy Attwood showed a video about the International Space Station (ISS) demonstrating zero gravity as due to free-fall in obit at 5 miles per second around Earth.  He then discussed how to spot the ISS, why it cannot be seen during the day or night, but only near dusk (within 1/1/2 hours of sunrise and sunset) when it is illuminated by the Sun while the sky is dark above.  The ISS has an orbit inclined 53 degrees to the equator.  The Heavens Above website shows the orbit in real time and can predict passes for all locations including Mississauga – a good pass coming on June 3.  Red ISS flares can be seen when the station is in a red sunset and sunlight reflects off the panels.  When the space shuttle is launched,  it achieves 99% of its velocity in the first minute and it is therefore difficult to change its orbit later on. 

He spoke about other bright satellites including the Iridium series and their flares. 

Randy showed 2 videos from NASA TV outlining the next space shuttle mission STS-117 which will install new solar panels on the ISS, and about building the space station.

 

 

The Moon Facts and Fiction

 

Bob McCall spoke about various aspects of the Moon.  Any “zork” (dark body illuminated by a star) larger than Ceres is spherical and can exhibit phases.  The slower the rotation, the closer the body to a sphere.  The zork is half-lit and phases are an optical illusion.  He described the phases and stated that “3rd quarter” is incorrect terminology and should be called “last quarter”.  “Blue Moon” in popular culture means two full Moons in one month. The true blue Moon is an atmospheric phenomenon caused by forest fires and smoke in the air.  The term “waxing” refers to the interval from new to full Moon; waning to the interval full to new.  Finally, Bob spoke about the force of gravity in relation to the inverse square law of distance from the Moon.

 

 

The Sky Tonight, the “Great Debate”

 

Roy Swanson described the astronomical sights for June. The month has two full Moons. Occultations of the Pleiades and Jupiter will take place.  The asteroid Vesta is especially close to the earth and will be visible (faintly) with the naked eye above Jupiter in Scorpius.

On May 10, an article in the Life Section of the Toronto Star titled “Heavenly Invitation” mentioned the International Sidewalk Astronomers Astronomy night. Roy recommended that we consider it for Next Year for the Mississauga Centre.  Randy suggested a Port Credit Sidewalk night.  William Callahan noted that dark sky nights are held in Bracebridge.

At  the 76th meeting on January 26, 2007, Roy stated that the New Horizons Mission to Pluto was launched in January to take advantage of the increased speed of the Earth’s orbit during perihelion.  At the 80th meeting on March 23, 2007, Chris Malicki stated that the orbital energy is the same everywhere in the orbit and as a result there is no particular advantage in launching in January.  Roy posed the question to two astronomers on “Ask the Astronomer” websites. He received one answer supporting Chris and another supporting his own position and declared the debate to be a draw.  

 

 

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