Late on Friday, the Journal of Cosmology (a free but peer-reviewed scholarly journal) published a paper on their website by NASA astrobiologist Dr. Richard B. Hoover that showcases a variety of microscopic fossilized structures from inside meteorites that are possibly the remains of extraterrestrial bacteria. Aliens, for real.
Obviously, if these structures prove to be the actual remains of alien bacteria, this is incredibly huge news. We're talking one of the most significant discoveries in human history, proving that life (in some form) is not only not unique to Earth, but in fact likely prevalent throughout our solar system on comets and moons and likely just as prevalent across the tens or hundreds of billions of other planetary bodies in our galaxy. It also implies that life itself probably didn't originate on Earth, but probably came here from space. It's absolutely mind blowing.
So here's the deal on what Dr. Hoover found. He sterilized, and then cut open a bunch of carbonaceous chondrite meteorites, which are meteorites that tend to contain lots of water and organic material like amino acids. Hoover then examined the freshly exposed insides of the meteorites with an electron microscope, and inside he found lots (lots) of what he says seem to be 'indigenous fossils' of bacteria. Many of the fossils were embedded directly in the rock, and the lack of nitrogen in them makes it unlikely they they came from Earth, according to Hoover. So in this case, 'indigenous' means that the bacteria may have arrived on Earth along with the meteorite: natively, they'd be aliens. ALIENS!
What's particularly interesting about these fossils is that a lot of them are very familiar looking. Specifically, they look a lot like terrestrial cyanobacteria, which are arguably the most successful and resilient form of life on Earth. There's also a lot of them that are "just very strange," according to Hoover.
Pretty much the entire scientific community is, understandably, extremely skeptical about this news, considering what it implies, the fact that such claims have been made before, and the more likely (but less exciting) explanations that the structures are either not bacteria or are of terrestrial origin. The paper, in its entirety, has been published online, and is currently being vetted by 100 experts and 5,000 other scientists. All of their reactions and commentary will also be published online in the next few days. According to the journal, "no other paper in the history of science has undergone such a thorough vetting, and never before in the history of science has the scientific community been given the opportunity to critically analyze an important research paper before it is published." So at this point, we'll just have to wait and see what happens.
In the gallery below are a selection of images of the hypothesized alien bacterial fossils, along with images of similar terrestrial bacteria. The image captions are directly from the paper. These structures may not look like much, but just remember, you could be looking at the first ever pictures of actual alien life.