Mary Ann Foster is one lucky woman - she survived a bonk in the head from a "space ice" that crashed through the roof over her bed!
Mary Ann and her husband think that the ice is from outer space, and so they're saving it next to the bagels in their freezer ...
Link (Flash video on nbc4)
I am writing from Spain.
There are several articles about megacryometeors which were published in scientific journals (e.g. Journal of Atmospheric Chemistry, Journal of Chromatography, Geotimes, AMBIO: Journal of the Human Environment).
The last one about a chunk of ice weighing more than 10 kg was published in Journal of Environmental Monitoring giving an analytical protocol for other similar events. Here you can read a comment about it by Katherine Davies:
http://www.rsc.org/Publishing/ChemScience/Volume/2008/04/falling_ice.asp
The use of different techniques unequivocally has confirmed that they formed in the Earth's atmosphere, specifically in the troposphere.
They are not blue ice from waste water from aircrafts as they are not blue (obvious) and the Gas Chromatographer-Mas Spectrometer indicated the lack of organic compounds (which are common in the blue desinfectant).
The ice does not come from aircraft icing as the ice textures are different from classical ice formed in the fuselage, and also they don't come from tank water leakage as they display hydrochemical and isotopic heterogeneity (mainly based on the deuterium mapping) and fabric properties which confirm a complex history of formation in the atmosphere (like hailstones).
The historical study verify the existence of references of ice falls which are previous to the invention of the airplanes.
There is an interesting website about megacryometeors:
http://tierra.rediris.es/megacryometeors/index2.html
I hope this information can be of help.
Cheers,
Maria
...Meh, with all of the air pollution it would probably melt down to the size of a chihuahua's head.