On 28 Oct 2007, at 14:46, Joe Bauman wrote:

What are the chances it will become a daytime object? And will it show a tail one of these days? Thanks, Joe

I don't know, but my best guess is (1) no it will definitely not be a daytime comet and (2) whether it shows a tail is uncertain and cannot be resolved with any certainty. The best stance is to enjoy its unique "head-on" view that we are now seeing that obscures most of its annular shape. See, e.g. in the Utah Astro wiki - http://www.utahastronomy.com/Current_observing_events#From_the_web - the following collected high contrast images that show detail in the diffuse coma - Anton Oct 10-27 (Russia). Best high-contrast detail image made using ISIS rgradient command Paolo R. Lazzarotti Oct 10-27 High-contrast coma Polarization Difference Image Richard Crisp 10-25 Concerning possible tail growth, this is not Comet McNaught seen earlier in the year. Comet McNaught had a highly ellipcital orbit that took the comet within the orbit of Mercury. From that position - the Sun really baked the comet and produced the huge 40 deg tail seen in the southern hemisphere. Comet 17P orbit - although inclined to the ecliptic - is almost entirely within the orbit of Mars and Jupiter - if viewed from the north ecliptic pole. That is why 17P's period is only 6.88 years. 17P is also on its outward bound leg - it passed perigee back in May. It should be getting dimmer - not have a huge outburst. In that Mars-Jupiter orbital bracket, Comet 17P is not going to be subjected to the types of intense solar radiation that creates the type of long-tail seen on Comet McNaught. Conversely, the diffuse coma of this comet is huge - now as big as the Sun. As one former astronomy college professor put it on a usenet group - "All that gas has to go somewhere." The key points about Comet 17P are its crazy unique characteristics. a) A small short period comet that should be dimming into astronomical obscurity suddenly blossoms into thermonuclear sphere (if it is a sphere) - for no apparent reason. Some speculative amateur-web suggestions are i) an impact with another comet or asteriod or ii) it is breaking up from the gravitational influence of Jupiter. b) Looking at its rate of expansion - the speed of the expanding wave front on this comet has been estimated (by an amateur) at 1,500 km/ per hour. c) It is presenting a unique "head-on" apparent view towards Earth. Most comets are seen from the side. Comet 17P has been a nice suprise warm-up for Comet Tuttle's scheduled return beginning around Christmas. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net