Panspermia

Did life evolve on Earth, or did it arrive from space?

This article was prompted by articles in the U.K. Daily Mail and Daily Mirror.  There is nothing new in these news reports: Milton Wainwright has been writing about this titanium sphere for some years.

Did aliens send this metal orb to seed life on Earth? Riddle of microscopic sphere found 16 miles up, oozing slime which may contain microorganisms.

Dr Milton Wainwright from the University of Sheffield used balloons to collect samples of dust and particles 16 miles up in the Earth's atmosphere

In one sample he found a tiny metal ball that left impact crater in the device
He claims the orb may have been travelling fast as came from outer space
The metal ball is the same width as a human hair and is made from titanium
Dr Wainwright says it could have been sent to Earth by intelligent alien life
He claims a gooey substance was oozing out of the ball and is biological 

Daily Mail - 16 February 2015

Mysterious metal globe 'may be proof aliens are watching us and created life on Earth'
Daily Mirror - 16 February 2015

An aside on the manufacture of spherical objects

Ball bearings

"How Do You Get Round Balls?" 

Three centuries ago, an astonishingly simple manufacturing method had been developed for balls made of stone, e. g. marble ... Lumps of stone were hammered into squares with rounded edges and put on stone plates with concentric grooves; then a wooden plate was put on top and run as a water wheel, until, after one, two or three days, the squares had become balls.

Sheldon Brown, bicycle expert and humorist. 

Lead shot

Lead shot manufacture by hand is a time-consuming process.  Shot can be manufactured by tumbling in a drum or barrel.  Although tumbling is still used as a finishing or polishing method in many trades and hobbies it is no longer used commercially to produce shot.  The tumbling method was superceded by a method in which molten lead was dropped into water.  It was soon found that longer drops produced rounder shot, which led to the invention of the shot tower.  A particularly famous and interesting shot tower is the Phoenix / Baltimore / shot tower.

Illustration from The Baltimore Shot Tower.

Sphericity in nature.

Objects which are spherical, or nearly so are common in nature.  We can ignore planets and suns, which tend to be oblate spheroids and which would have a hard time carrying life-forms through Earth's atmosphere in any meaningful and survivable way.  The other end of the scale shows greater promise.

Hailstones
.