Sri Lankans have December 29, 2012, deeply engraved in their memory. That day - better yet, that night - many witnessed a fireball lighting up the skies over the province of Polonnaruwa, spraying fragments across the countryside.

Some meteor fragments found their way to scientists at the Sri Lankan Medical Research Institute of the Ministry of Health, and what came next is what made these events interesting. 

Test results, Sri Lankan scientists claimed at the time, showed that the stones contained fossilized biological structures fused into the rock matrix.

They said their tests had revealed the rocks contained diatoms -- a type of algae, microscopic plant life, that have hard outer shells made of silica and come in a variety of shapes and forms. They also claimed to be sure that their tests ruled out any possibility of terrestrial contamination.

When a paper by Chandra Wickramasinghe on the issue was published online in the Journal of Cosmology, it went viral.

The idea that the cosmos had FeDex'd us a sample of extraterrestrial life was very appealing -- and the news certainly drummed its share of attention.

However, soon enough researchers started finding incoherencies both in the popular accounts of the event and the results proposed by Wickramasinghe, which resulted in a growing skepticism around Wickramasinghe's paper.

For instance, in the wake of the meteorite shower, many people claimed getting burned by the celestial fragments and smelling noxious fumes. Researchers found it hard to take in the claims involving burns and such, since most meteorites are cold upon impact. They spend a lot of time in deep space (where it's cold) and are only heated briefly (like, for a few seconds at most) as they plow through the atmosphere.

And, in addition, to many researchers it was unclear how Wickramasinghe's team had eliminate the possibility of Earth's contamination; that is, diatoms could have gotten into the samples because those rocks were sitting on the Earth where diatoms are everywhere. After all, of the hundreds samples of rocks handed in to the Sri Lankan scientists by police and popular efforts, only three were considered genuine meteorites.

Finally - probably Wickramasinghe's biggest blow - he and his team didn't consult with outside experts (including those in the fields of meteorites and diatoms); they didn't get independent confirmation from an outside lab, and they published in a journal that is, um, somewhat outside the mainstream of science.

In other words, it wasn't weeks before Wickramasinghe's paper and claims were thrown into oblivion by international scientific community.

And everything seemed be getting back to normal. Until now, that is. A recent paper, again by Wickramasinghe's team has been published, furthering the claims, and it's getting picked up by mainstream media.

Well, only time will tell how far they will get this time.