Mysterious Object from Beyond has significant shock value.

Fri, 02/09/2018 - 15:50 -- Anonymous (not verified)

No, it’s not a sci-fi movie, but rather the unique Swedish fossil meteorite Oesterplana 065 which is the subject of a paper published last week in Meteoritics & Planetary Science by Postdoctoral Scholar Surya Rout (now at the University of Bern, Switzerland), Robert A. Pritzker Associate Curator for Meteoritics and Polar Studies Philipp Heck, and Field Museum Research Associate and Professor of Geology Birger Schmitz (Lund University of Sweden). Informally, this fossil meteorite is also called the “Mysterious Object,” as its mineralogical and chemical composition is different from all other meteorites found so far (see earlier report on this). The meteorite itself was found embedded in roughly 470 million year old marine limestone in Southern Sweden. As in all fossil meteorites most minerals have been replaced during the fossilization process, and studying them does not provide much useful information about the meteorite. The exceptions to this are chromium oxide minerals like chromite and chrome-spinel, for which chemical compositions are well preserved. In Chicago, Surya, Philipp and Birger used Raman spectroscopy and scanning and transmission electron microscopy to study these resilient minerals. In particular, they were looking for effects in the crystal structure that were caused by a massive collision in space. They found that the minerals in the “Mysterious Object” were thoroughly shocked, as they display numerous microcracks and dislocation features in their crystal structure. This makes the “Mysterious Object” the most shocked fossil meteorite found so far. This is consistent with the hypothesis that it actually could be a piece of the impactor that led to the major asteroid breakup that caused a prolonged rain of meteorites roughly 470 million years ago. The new paper is available online. To learn more about fossil meteorites be sure to visit the Field’s new interactive meteorite exhibit in the Grainger Gallery. The exhibit does not feature the “Mysterious Object,” but it does have four other 470-million-year-old fossil meteorites found in the same location and an interactive CT scan of a fossil meteorite on a large touch table.
- adopted from FMNH Natural News.

Back-scattered electron image of shock features of chrome-spinel in the "Mysterious Object".