Traditionally, scientists have had chemical and mechanical explanations for the creation of spheres, but lately a new approach has been investigated: electric arcs in plasma.

	On January 25, 2004, “Opportunity,” the Mars Rover made a discovery of spherules embedded in the iron rich soil of Mars.  Their bluish color made them pop out against their background and hence they became known as blueberries.
	C. J. Ransom,  a plasma physicist of Vemasat Laboratories found these blueberries a mystery.  In his experiments he was able to duplicate these spherical formations in the lab using electrical arcs in a plasma.  No other method was successful in reproducing the formations found on Mars.

 When it comes to creating spheres with electrical arcs in plasma, the process is entirely scalable.  Which means that little arcs create small spheres and big arcs create big spheres and gigantic arcs create gigantic spheres.  Spheres are found in Earth’s geology as well.  When found, it has been proposed by some scientists  that they also were formed by electrical arcs in plasma.  Not all scientists agree with this hypothesis at this point, but it is supported by experimentation.  See Plasma Generated Spherules by C.J. RANSOM

REFERENCES: 

 http://absimage.aps.org/image/MWS_APR05-2004-000006.pdfb

http://www.thunderbolts.info/tpod/2005/arch05/050325blueberries.htm