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The Polonnaruwa meteorite is an alleged meteorite that fell in 29 December 2012 close to the city of Polonnaruwa in Sri Lanka, and recovered soon after by Chandra Wickramasinghe's team. Twelve days after the Polonnaruwa meteorite was "seen falling" to Earth, Chandra Wickramasinghe published in the online fringe science ''Journal of Cosmology'' that, after studying some electron micrographs, his team discovered fossilized diatoms (microscopic phytoplankton) inside the meteorite as well as cells similar to those found in the Red rain in Kerala that fell in 2001.〔〔 In addition, his team of scientists reported in a separate article that they are certain that it is a meteorite that originated from a comet and that it also contained living diatoms.〔〔 The rock is not deemed by peer scientists to be a meteorite,〔〔 so it was not recorded in the international Meteoritical Society database.() ==Criticism== Though Wickramasinghe claimed that these microscopic shapes constitute strong evidence for panspermia,〔 astrobiologists have determined in the past that morphology cannot be used unambiguously as a tool for primitive life detection. In 15 January 2013 a diatom expert, Patrick Kociolek, verified that the forms pointed out in the paper are indeed diatoms. Then he added: Meanwhile, PZ Myers, who studies evolutionary developmental biology, questions "why a space organism would evolve to look ''exactly'' like a species that evolved in a completely different environment, and how it could have converged in all its details on such remarkable similarity to a specific Earthly species? Why, we might even suggest that it clearly looks like contamination." While ignoring the environmental influence in evolution, a proponent of the panspermia hypothesis, Brig Klyce, contends that since life on Earth and life from space are closely related, resemblance would be expected. Wickramasinghe's research paper was not peer reviewed by experts prior to publication, and early on, there were claims that Wickramasinghe's article was not an examination of a meteorite but of some terrestrial rock. Scientists from the Peradeniya University Geology Division, and the Department of Forensic Medicine, as well as the Arthur C. Clarke Institute for Modern Technologies in Sri Lanka examined fragments of the alleged meteorite, and concluded that it is a terrestrial rock formed by lightning strikes (fulgurite). The silica and quartz bulk content confirms the terrestrial fulgurite explanation, and further discards the meteorite hypothesis, as any silica in a meteorite would be present in trace amounts.〔''(Meteorite or meteowrong? )''. Department of Earth and Planetary Sciences, Washington University in St. Louis. Quote: "''If you can see quartz with the naked eye, then the rock is not a meteorite."''〕 Another proposed explanation holds that the alleged meteorite did arrive from space, but is associated with the billions of tonnes of terrestrial material that asteroid impact events have previously blasted into space during the Earth's geological history. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Polonnaruwa (meteorite)」の詳細全文を読む スポンサード リンク
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