In response to the "red rain" in India, there were several prominent theories, the most intriguing of which have been de-bunked. Several scientists believed that it was cosmic dust of some sort from a passing asteroid. Along with that theory, some believed it to be an extra-terrestial form of microbial life.
Unfortunately, scientists are now withdrawing those claims and issuing statements which tell us that the red pigment came from some type of algae or moss.
I would like to know where this purplish color might be coming from though.