The study concerns the team's claims to finding clear evidence of fossilized Cyanobacteria in the interiors of certain types of Carbonaceous Chondrite meteorites. [designated "CI1s"]. This class of meteorites was selected because [as far as I can tell] of the characteristics of their interior geology, making the case that you are NOT looking at terrestrial contamination easier. The most famous meteorite in the CI1 class is the Orgueil, which fell in France in the 19th century, and has been studied more than any other outer space visitor. [a picture of a piece of the Orgueil is at the left].The electron microscopy of some of the bacteria-like filaments found by NASA is striking [please Google the paper to see them--I got a little lazy it seems and didn't download any for easy inclusion here], but the microscopy doesn't stand alone. Chemical constitution tests of elemental ratios were done on specific filamentous structures, which exhibit a greater carbon-content richness than surrounding matrix. The main evidence for the "likeness" to Earth-born cyanobacteria is, however, the microstructure. This is probably the final brick in the wall to getting the conservative establishment to include this sort of discovery in the textbooks---sort of Science's Imprimatur on the Truth.
This is great for the exploratory adventure that we in the human race are on, and fits nicely into what everyone was ready to believe anyway---that is typically the way of Science, at least in the textbook stage. It, of course, does nothing to help us in UFOlogy. Extraterrestrial fossil bacteria are a long [psychological] distance from currently visiting alien technology---and the two are miles apart in laboratory-style evidence. So...Nice, but not to get cocky about in our commentary.
For me, there was an added bit of "fun" in this. I own a piece of the Murchison meteorite. The Murchison is also a carbonaceous chondrite, though not a CI1. It is a CM2, probably the next clearest example of a potentially non-contaminated-and-demonstrably-non-contaminated specimen. A piece of the Murchison is shown next above on the left. [It looks very much like my own, but bigger]. The Murchison easily out-competes the CI1s in carbon-content and bio-organic molecules [90+ varieties of amino acid-like molecules have been found there, including almost all the terrestrially biologically-active ones----you probably could "eat" an extract of the Murchison if you were "Lost-in-Space" and were desperate and had the extraction technology.] This new paper may open up the field to re-exploring the Murchison and other carbonaceous chondrites for further strong evidence of ET life. That would be extra fun for me just to childishly hold the thing in my hand.
I also am blessed with a piece of the Allende carbonaceous chondrite, but it will probably not contain fossilized alien life. It is VERY rich in carbon-containing molecules, but is is very old. [a picture of a piece of the Allende is at the bottom]. This meteorite is considered perhaps the oldest known bit of matter on Earth, estimated to have been formed in a supernova burst over 4 1/2 billion years ago. Some folks think that a rain of stuff like the Allende formed the resident bio-organic "pool" of resources to get Life on its early start.