On Dec. 29, 2012, a meteorite crashed into the province of Polonnaruwa, in Sri Lanka. Witnesses reported the fireball smelled of tar.
But when local authorities gathered samples of the space rock and sent it to the Sri Lankan Medical Research Institute of the Ministry of Health in Colombo, officials at the center found some strange things about the meteorite. They then sent the samples to a team of astrobiologists at Cardiff University in the UK.
The researchers at Cardiff analyzed the samples, and their results were released Monday. The results could be groundbreaking: the samples contain fossilized biological structures fused to the meteorite’s rock matrix. But more importantly, the team also ruled out any terrestrial biological contamination. If the results hold up, these fossils came from space.
Out of the 628 rock fragments that were sent to Cardiff’s Jamie Wallis, only three were ruled to have been part of the meteorite. One of the samples had a small density (1 gram per cubic centimeter), smaller than any other known carbonaceous meteorites. It also had up to four percent carbon content and a partially fused crust, which suggests the rock endured atmospheric heat. The rock, believed to be a small comet, also contained many organic compounds.
But most importantly, the researchers found what appears to be a microfossil in electron microscope images of the sample. The fossil is about 100 micrometers across and resembles a family of mostly extinct marine dinoflagellate algae. The team also found a flagella fossil 100 micrometers long with a 2 micrometer diameter. Wallis suggests that an organism shaped like this lived in a low-pressure, low-gravity environment, reports the MIT Technology Review.
So where did these fossils (if they are fossils) come from? Low nitrogen levels, too low for modern organisms, in the samples prove that they were not contaminated by modern organisms. The fossil’s buried location in the rock also supports this.
This Sri Lankan rock may hold proof of panspermia, the theory that life exists throughout the universe and hitches a ride on comets to planets, where the microorganisms colonize and evolve into diverse fauna.
“The presence of fossilized biological structures provides compelling evidence in support of the theory of cometary panspermia first proposed over thirty years ago,” the study said.
Another explanation (that’s a bit more believable) is that the comet is of terrestrial origin, but it just hasn’t visited in a while. In Earth’s younger years, it was bombarded by comets and asteroids, some of which were large enough to knock chunks of the Earth into space (a particularly big chunk became the moon). A fragment of Earth knocked into space could have eventually found its way back to our planet, having been stuck in orbit for millennia.
You can find Wallis' study here.
