The infrared emission of various comets can be matched within the framework that all comets are made of aggregated interstellar dust[ This is demonstrated by comparing results on Halley "a periodic comet#\ Borrelly "a Jupiter family short period comet#\ HaleÐ Bopp "a long period comet#\ and extra!solar comets in the b Pictoris disk[ Attempts have been made to generalize the chemical composition...

Gas phase formaldehyde concentrations were measured during the 2004-5 CHABLIS campaign at Halley research station, Antarctica. Data coverage span from March 2004 through to January 2005 thus capturing the majority of the year. Factors controlling HCHO concentration include local chemical sources and sinks, and exchange with the 5 snow surface. The measured seasonality is in line with previous o...

The 12C14N/12C15N and 12C14N/13C14N isotopic ratios are determined for the first time in a Jupiter-family comet, 88P/1981 Q1 Howell, and in the chemically peculiar Oort Cloud comet C/1999 S4 (LINEAR). By comparing these measurements to previous ones derived for six other Oort Cloud comets (including one of Halley-type), we find that both the carbon and nitrogen isotopic ratios are constant with...

Plasma observations near comet Halley indicate that around 1.6x105km from the nucleus a newly discovered sharp boundary (cometopause) separates the solar wind controlled external and the heavy cometary ion dominated internal regions. Such a discontinuity was previously not predicted by theoretical models. Inside the cometopause (in the cometary plasma region) the protons and heavy ions move wit...

Pg. S3, Paragraphs 1-4. I fully agree with the reviewer that the Whipple “dirty snowball” was hit hard by the results from the probes to comet Halley. However, the “dirty snowball” model has continued to persist, despite all data to the contrary and it is for that reason that I chose the word “paradigm.” That seems to be the nature of paradigms; they are so deeply entrenched into the consensus ...

The choice of a member of a parametric family of iterative methods is not always easy. The family of Chebyshev-Halley schemes is a good example of it. The analysis of bifurcation points of this family allows us to define a real interval in which there exist several problematic behaviors: attracting points that become doubled, other ones that become periodic orbits,... These are aspects to be av...