image: A meteorite fragment found after a 17-20 meter asteroid disrupted in the atmosphere near Chelyabinsk, Russia on Feb. 15, 2013. The blast wave produced by this event not only caused damage over a wide area but also created a strewn field of stony meteorites like this one. The meteorite is an ordinary chondrite (type LL5). It shows a beautiful contact between impact melt (dark material at top of image) and chondritic host (light material at bottom of image). Chondrules (circular features) are visible in the chondritic host at the bottom and right-hand side of the image. Portions of the chondrite were broken or otherwise separated and have migrated into the impact melt. The impact melt is estimated to be 4452±21 (Popova et al. 2013) and 4456±18 million years old (Lapen et al. 2014). These ages match the ~4470 million year old age of the Moon predicted by our model. We argue these impact melts were likely created when high velocity debris from the Moon-forming impact hit the parent asteroid of the Chelyabinsk bolide and heated near-surface material. This material relates to a paper that appeared in the April 17, 2015 issue of Science, published by AAAS. The paper, by W.F. Bottke at Southwest Research Institute in Boulder, CO, and colleagues was titled, 'Dating the Moon-forming impact event with asteroidal meteorites.' view more
Credit: [Credit: Vishnu Reddy, Planetary Science Institute]