A friend of mine (who previously attended an Appleseed) posted this on my Facebook profile today... Thought this group would appreciate it. Anyone want to double-check my math?
(http://www.samuelayres.com/randomcrap/rwva/mars_moa.jpg)
FD
Here is what I get: 102,393 miles is 1 MOA (arc minute) at 352 million miles.
100 yards is approximately 33.3 microarc seconds at 352 million miles.
arc minute (MOA)
arc second (1/60th of an arc minute)
milliarc second (1/1000 of an arc second)
microarc second (1/1000 of a milliarc second)
So much math it makes my head hurt. The analogy here is this, with much determination and effort NASA hit the mark. Anyone who applies themself to becoming a Rifleman can do the same.
I also get about 98k miles = 1 MOA at 352 million miles.
Not to diminish NASA's and JPL's accomplishment, but they did get a few chances to do mid-course corrections on that shot. On the other hand, the come-ups in multiple gravity fields are positively freaky!
Dave
Quote from: Edheler on August 06, 2012, 09:01:54 PM
Here is what I get: 102,393 miles is 1 MOA (arc minute) at 352 million miles.
100 yards is approximately 33.3 microarc seconds at 352 million miles.
arc minute (MOA)
arc second (1/60th of an arc minute)
milliarc second (1/1000 of an arc second)
microarc second (1/1000 of a milliarc second)
Where'd you get 102,393 miles? This is how I did the math:
352,000,000 miles = 619,520,000,000 yards
1 MOA = 1" per 100 yards
1 MOA = 61,95,200,000 inches at 619,520,000,000 yards
619,520,000,000 yds = 97777.8 mi
Quote from: Hinermad on August 06, 2012, 09:31:58 PM
I also get about 98k miles = 1 MOA at 352 million miles.
You're getting that result because you're using 1" is 1 MOA per 100 yards. We round it down because it doesn't matter for 4 MOA accuracy out to 500 yards. An approximation with 4 significant digits is: 1.047" is 1 MOA per 100 yards.
To eight significant digits: 1.0471976" is 1 MOA per 100 yards
To twelve significant digits: 1.04719755858" is 1 MOA per 100 yards.
Rounding really bites at 352 million miles. ;)
Makes sense then... I still want to see a grouping of at least two more shots before I make any determination as to whether or not they're shooting to standard. ;D
Quote from: Foppish Dandy on August 06, 2012, 09:51:13 PM
Makes sense then... I still want to see a grouping of at least two more shots before I make any determination as to whether or not they're shooting to standard. ;D
Knowing NASA they would be more concerned with hitting their existing very expensive SUV on Mars if they sent more. ;D
Quote from: Edheler on August 06, 2012, 09:40:19 PM
You're getting that result because you're using 1" is 1 MOA per 100 yards. We round it down because it doesn't matter for 4 MOA accuracy out to 500 yards. An approximation with 4 significant digits is: 1.047" is 1 MOA per 100 yards.
Guilty as charged.
tan(1/60) x 3.52E8 = 102,392.652 miles.
Dave
:pop:
Quote from: Foppish Dandy on August 06, 2012, 09:51:13 PM
Makes sense then... I still want to see a grouping of at least two more shots before I make any determination as to whether or not they're shooting to standard. ;D
Quote from: gonejohnny on August 07, 2012, 11:08:43 AM
:pop:
Quote from: Foppish Dandy on August 06, 2012, 09:51:13 PM
Makes sense then... I still want to see a grouping of at least two more shots before I make any determination as to whether or not they're shooting to standard. ;D
Well who knew our AS folks were so proficient in their math skills ;)
I'm with GJ, im just gonna sit back and watch ya'll do the math! I ran out of fingers and toes a long time ago! :pop:
Quote from: Foppish Dandy on August 06, 2012, 09:51:13 PM
Makes sense then... I still want to see a grouping of at least two more shots before I make any determination as to whether or not they're shooting to standard. ;D
First shot (in the target) may be luck, second shot may be cooincidence, third is skill.
But gotta give them credit for limiting their shots, after all look at the cost per round!
It isn't about 5 cents per shot like a .22LR! ;D
Thanks, EDheler, for posting the info. :)
Gary