What are the chances it will become a daytime object? And will it show a tail one of these days? Thanks, Joe On Oct 28, 2007, at 2:22 PM, Kurt Fisher wrote:

In a Cloudy Night's forum, someone pointed out that you can use the Google search box's built-in calculator to find the physical size of Comet 17P. In general -

sin ( radians (your_arcmins arcmins) ) * 1.62900 [a.u.] * 149 597 871 = physical size 17P

Get the current day's distance to Comet 17P from the NASA-JPL Near Earth Object orbit simulator -

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=17P&orb=1

An example of a string that is formated for use in the Google search box is:

sin(radians * (10 arcminutes)) * 1.62900 * 149 597 871

which yields = 708 878.821 kilometers

According to Allen's Astrophysical Quantities, typical comet coma physical diameters are 10,000 to 100,000 km.

- Kurt

Updated to Utah astro wiki current events

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