Estimate of physical size of Comet 17P: 2 arcmins = 120 arcsecs =~ dia. 142472 kilometers 3 arcmins = 180 arcsecs =~ dia. 213708 kilometers Computations - using the sine rule 1 a.u. = 149,597,870.691 kilometers ; wikipedia Distance Earth to Comet 17P Oct 25 = 1.637 a.u. ; NASA-JPL Near Earth Object simulator Distance Earth to Comet 17P Oct 25 = 244,891,714 ; Product Comet 17P object size: 2-3 arcmin ; my obs and other internet reports Physical diameter using the sine rule from object's diameter in arcsecs: Physical diameter = [ Deg2Rad( Objdiameter_arcsec / 3600#) ) * Distance_to-Object ] Results for 120 and 180 arcsecs: 120 arcsecs =~ 142472 kilometers 180 arcsecs =~ 213708 kilometers Diameter of major planets ; wikipedia Jupiter 142985 km Saturn 120534 km - Kurt P.S. - Misread another chart value for the a.u.'s between 17P and Earth. Double-opps! _______________________________________________ Sent via CSolutions - http://www.csolutions.net