Comet 73P/Schwassmann-Wachmann 3 (SW3) Bulletin #6

April 28, 2006

Michael L. Sitko, University of Cincinnati & Space Science Institute

New Images of SW3-B&G from the Hubble Space Telescope show that both are really crumbling into innumerable pieces, many of which may only last a few days (if that). In the image below you can see B in the left image, and G in the right image.

The image below gives a sense of scale for the observations. Most of the debris from B is still within a few seconds of arc from the main body.

And Carl Hergenrother also has good ground-based images for G, such as this image obtained on April 27:

Hopefully, the ground-based monitoring will continue unabated. Unfortunately, Hubble is heavily over-subscribed and (I suspect) will probably not obtain daily imaging of SW3. It will also be unable to observe the comet when it passes into the solar avoidance zone, which effectively grows considerable in the 2-gyro pointing mode compared to the original 50 degree angular separation from the Sun of the 3-gyro mode. Right now, the observations seem to benefit from being on the ‘good’ side of the Sun. If SW3 were an early evening object, this would not be the case.

Finally, NASA has put out a press release to re-assure everyone that none of the fragments of SW3 will hit the Earth on May 25. Think this will shake some people’s beliefs in alien messages hidden in crop circles? Sadly, I doubt it.

For more information, contact:

Mike Sitko

Dept. of Physics, University of Cincinnati sitko@physics.uc.edu Phone: 513.556.0642

& Space Science Institute, Boulder, CO sitko@spacescience.org