Fading splatter in Illustrator

I've recently started to work with Illustrator and I was wondering if there is a way to make a stroke like this:

 

Yes, there is a way.
With "Blend" Option in illustrator you can achieve this type of stroke.

Follow these steps:

1. Draw 2 circles A & B. (A smaller and B bigger) apart from each other(either horizontally or vertically. No matter).
   
   
2. Fill smaller circle with gray and bigger with black color. Remove stroke on both the circles.
   
   
3. If you are using Illustrator-10, locate "Blend" tool underneath gradient tool. Select blend tool.
   
   
4. With blend tool selected, first click on gray circle and again click on black circle.
   A row of circles (in straight path) will be formed automatically with gradient shades from circle A to B in increasing order.
   
   
5. Make sure the object on stage is selected.
   Choose "Add anchor Point" pen tool and add an anchor point on the straight path.
   
   
6. Choose "Conver Anchor Point" tool and modify straight line in to curved line as needed.
   

You can adjust the radius of the circles by expanding them.
Choose Object>Blend>Expand to expand all the circles.
After expanding you can select the individual circles with "Direct selection Tool". Reduce the size of required circles with "Free Transform Tool".

There may be another simple way of doing it.
But I expressed my way of doing it.

Please let me know if anything is confusing.

 

Thank you very much!