Mississauga Astronomical Society
                                                                    Fourteenth Meeting

                                                                    Speakers’ Night

 Day:              .   Friday, January 23, 2004     

Speakers:     Randy Attwood 
                          Stephen Barnes   -  Guest Speaker
                        


Mars Exploration Rover NASA briefing

Randy Attwood showed a news briefing recorded from NASA TV regarding the status of the Mars rovers, and specifically the Spirit Rover. Spirit landed on Mars on Jan. 3 and was functioning successfully until Wed. Jan. 21 when meaningful communication ceased. The news conference of 5 engineers, managers and scientists detailed the problem with Spirit and spoke about the landing itself, and the imminent arrival of the Opportunity Rover in the next day and a half.

Spirit went into a processor reset mode similar to a repetitive computer reboot. An anomaly team has been set up to study the problem and to find a way to restore functionality to the spacecraft. Project Manager Peter Theisinger indicated that days or weeks could pass before Spirit would be functional again and that full function would likely not be achieved. It was not known but was suspected that this could be a hardware rather than a software problem.

Meanwhile, the flight engineers presented interesting data showing that 2 gusts of wind (at 40,000 feet and at 1000 feet) hit the rover on its descent. Spirit was able to correct for the horizontal wind with lateral rocket firings. The atmosphere was not as thick as expected partly due to a dust storm. This has prompted the team to program Opportunity to open its parachute 4500 feet higher than originally planned.

 Finally, Dr. Malin showed images taken by Mars Global Surveyor from orbit illustrating the rover landing site, backshell and parachute, heat shield impact location and bounce marks from the airbags around the spacecraft.  It was fascinating to see the rover located on the surface of Mars to as accuracy of ½ meter.

 

Webcam Astronomy and Photographing Mars from Florida

Stephen Barnes, President of the Hamilton Centre of the R.A.S.C. gave a presentation as part of a Speaker exchange program with the M.A.S.   Stephen has been interested in astronomy since the age of 8 when he received a 3” telescope. He now owns a telescope shop Sky Optics in
Burlington and his images can be seen at: http://www.skyoptics.net/gallery-2003.htm

The advantages of webcam images include the taking of many frames at least some of which are good, the ability for stacking, the ability to approach the diffraction limit of the telescope, and the low cost (as low as $100 for some webcams). Disadvantages include the small imaging area, limitation to short exposures and thus to bright targets, and the large file sizes obtained.

A big advantage is the availability of free software from the internet.
K3CCD TOOLS can be used to acquire video images, control the camera and do timelapse imaging.  Registax can align and stack frames.   Stephen recommended the use of a barlow or powermate for increasing magnification especially for planets. Good seeing at high altitude for the object is important when imaging. An IR passing filter helps to improve seeing and can be used for the red channel when making images. Jupiter especially suffers from atmospheric dispersion when it is low in the sky. A planetary atmospheric dispersion corrector is of considerable value in this situation.

Stephen showed examples of his lunar images with craters as small as 1 to 2 km resolved. In Copernicus Crater, the resolution approached an incredible 400 meters. Sun images with H alpha filter, Jupiter with 700 stacked frames and Saturn were shown.

Finally Stephen showed his Mars shots taken from the Florida keys where seeing is typically very good. During the closest approach of the planet in late August, a southern location placed Mars higher in the sky with resultant better seeing. The 4 to 5 nights that Stephen spent there enabled him to capture the planet with 120 degrees of rotation, although he did get the other hemisphere later in September from Ontario. His wonderful images of Mars are a testimony to the power of webcam imaging and to the skill of Stephen Barnes.


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