Mississauga Astronomical Society

Fortyfifth Meeting

Members’ Night

 

Day:                Friday, August 19, 2005

 

Speakers:         Randy Attwood

                         Ian McGreggor

                         Brian Cheaney

                         Jim Jackson       

 

                    

                              

News from NASA

Randy Attwood  showed excerpts from NASA TV about recent news from the agency including the SS Discovery launch (STS-119), Mars Reconnaisance Orbiter launch. The Cassini flyby of Mimas on Aug. 2 and the SOHO spacecraft 1000th comet discovery on Aug. 6.

 

News from NASA

Ian McGreggor spoke about recent happenings in astronomy.

In 1993 asteroid Ida was discovered to have a small moon. Since then, about 69 asteroids have been found to have a satellite, suggesting that most asteroids may have companions. On Earth, 3 craters dating back 2.3 billion years appear to be due to a triple collision; and there is evidence that the major impact crater in the Yucatan may also have had companion impactors. Now, asteroid 87 Sylvia (300 km diameter) has been found to have two moons. The first moon, 20 km in diameter was discovered in 2001 and in 2004 another one 7 km diam. Because Sylvia is the mother of the founders of Rome, the moons were named Romulus and Remus.

The STRINGS 05 conference in Toronto brought together 450 string theorists to the city. String theory postulates that the universe has 11 dimensions. When the theory first came out in 1984, there were 2 to 3 theorists in the field. Now there are 1,000. Strings are all theoretical with no experimental data. Theorists hope this will change when a super symmetrical particle (SUSY) is eventually found.

A new planet has been discovered: 2003UV313 at Palomar observatory.  With a diameter of 2800 km., 400km larger that Pluto, it is the largest object discovered orbiting the sun since Neptune. So, should this object be considered a planet. Some people say that if an object is a member of a group of objects such as the Kuiper belt it shouldn’t be considered a planet.  There is also controversy as to the discoverer. And in the same week two more Kuiper objects 75% the size of Pluto were found.

Ian spoke about the retirement of Richard West, a Danish astronomer who studied minor objects of the solar system, and a strong advocate of astronomy education in Europe. He discovered 4 comets, most notably Comet West in 1976 – one of the brightest of the 20th century.

In July Ian travelled to Austria. In the Natural History Museum there was an entire room devoted to meteorites many of them quite large.  In the same museum, there was an orery 7 feet tall from the 1750’s.  He also described the Zeiss projector in the planetarium at Klagenfurt.  

 

CCD Astronomy from the City

Brian Cheaney initially was interested in astrophysics. He then observed all the bright objects with a 6” telescope, then turned to the fainter ones, but they all looked like faint blobs and he felt like he was in a dead end. Now with the acquisition of a SBIG CCD camera, a new world has opened up to him. CCD’s are very sensitive to light and can pick up faint objects even in the light polluted city.  His setup includes a shed with a movable roof, 12” RCX 400 pier, home-made wedge computer in the shed and ability to control the setup from his house. He showed examples of many Messier and NGC objects he has imaged from his backyard.

 

Starfest

Chris Malicki discussed the Starfest held at Mount Forest.

 

Epicycles

Jim Jackson spoke about epicycles, mathematical constructs with no basis in reality and which are meant to prop up a theory of the universe. In Aristotle’s universe with Earth in the centre, problems arose with the outer planets, especially Mars, due to retrograde motion. Because people in centuries past believed that heavenly bodies affected human lives, it was important to know where the bodies would be located in the future. Ptolemy developed the theory of epicycles in which a planet orbits around an epicycle that orbits a deferent. Diameter and direction of the epicycle, speed, position of the Earth could all be adjusted but all movements had to be circular. Jim remarked that the ancient scholars were not willing to give up circular motion just as astronomers today are unwilling to part with the Big Bang theory of cosmology. Copernicus found that by replacing the Earth with the Sun, an easier model could be obtained. It was the mathematical not theoretical model that was important. Tycho Brache used a hybrid model with the Earth in the centre and planets orbiting the Sun (which itself orbited the earth). Kepler finally showed that epicycles were not necessary and that the planets moved in ellipses (3 laws of planetary motion).  Jim showed examples from a computer program which could model all kinds of motion including rectangles and stars using only epicycles.

 

Observing programs and Certificates

Ian McGreggor has been teaching astronomy for 35 years. It is his aim to have people interested in astronomy, observe with eyes and binoculars, and to be able to identify the constellations. He is concerned that people with a high tech background often don’t observe even the moon. He applauds the RASC observing programs with its four educational certificates: Explore the Universe, Messier, Finest NGC, Isabel Williams (moon).  Ian then described the Explore the Universe Certificate which he intends to use as the basis of an astronomy course. He encouraged the members of a club like our own to take on the project that this certificate entails.

 

Submitted by Chris Malicki, Secretary  Chris Malicki, Secretary                               back to M.A.S. meeting reports page
Mississauga Astronomical Society