Thread: Mars,morning of Oct 18th.
View Single Post
  #8  
Old 18-10-2009, 08:37 PM
matt's Avatar
matt
6000 post club member

matt is offline 		 
Join Date: Oct 2005
Location: Launceston, Australia
Posts: 6,570
Quote:
Originally Posted by Quark View Post
Thanks Matt, we are both correct regarding the size of the disk of Mars. You have listed the diameter and I have listed the radius. The ephemeris generator that I use lists the radius of Mars in arc sec's for any UTC input.



Thanks Lester, yes it was an early morning and I had only just hit the sack from processing my Jupiter data from earlier in the evening.

The radius of Mars for this image was 3.624 arc sec's which would make the diameter just over 7.2 arc sec's. In my post I listed the radius.
Oh.OK....

I'm not used to seeing the radius given as an object's size. I'm used to seeing its (entire) apparent diameter.

Thanks for clearing that up.

Can you explain the value/benefit of listing an object's radius rather than its apparent diameter?
Reply With Quote