Back in 2001, red rain fell on the Indian state of Kerala.
Dr. Godfrey Louis, a Professor of Pure and Applied Physics at Mahatma Gandhi University, collected samples, and put them under the microscope.
The rust-red cells he found had diameters averaging 10 microns, a little bigger than human blood cells.
Here’s where things get wild:
Over several months, Dr. Louis began experimenting with different temperatures to see if the cells would respond. As the temperature rose, he saw more activity. Eventually he got up to 300 degrees Celsius, which is 572 degrees Fahrenheit. He also increased the pressure to 300 pounds per square centimeter. It is assumed that normal Earth life would die at such a high temperature and pressure. But the red-walled cells in the Kerala rain water seemed to thrive.During his experimentation with temperatures and pressures, Dr. Louis studied the cells under a microscope. As he watched,the cells produced smaller cells internally that were colorless, or whitish. He began calling those new, little cells “daughters” of the original “mother” cells. Once he counted as many as fifteen daughter cells bud inside one of the adult “mother cells.” As the daughter cells grew, their cell walls also became red and eventually, the daughter cells erupted through the wall of the mother cell. This is clearly a process of replication. The budding is what provoked some biologist to say the red rain cells must be a form of yeast, since yeast cells also replicate by budding. But yeast cells have DNA, as all normal Earth biology has. On Earth, replication of cells requires the presence of DNA. But Dr. Louis could not find DNA.
So, he sent red rain water to scientists at Cornell University in the United States for isotopic ratio studies of the elemental composition of the red rain water. Elements confirmed so far are hydrogen, silicon, oxygen, carbon, and aluminum. No phosphorous was confirmed, which would be present if Earth DNA were present.
Prof. Louis also sent red rain cell water to Cardiff University’s Center for Astrobiology in Wales, directed by now-retired Prof. Emeritus, Chandra Wickramasinghe to see if DNA could be confirmed — but to date, DNA has not been confirmed.
Wikipedia has much more.