During the last week of this year, Cosmochemistry Papers will be on Christmas break. Normal service will commence on January, 2nd, after we have recovered.

Merry Christmas & Happy New Year to everyone and see you in 2017 !

¹Sota Arakawa, ¹Taishi Nakamoto
The Astrophysical Journal Letters, 832, L19 Link to Article [http://dx.doi.org/10.3847/2041-8205/832/2/L19]
¹Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan

Several pieces of evidence suggest that silicate grains in primitive meteorites are not interstellar grains but condensates formed in the early solar system. Moreover, the size distribution of matrix grains in chondrites implies that these condensates might be formed as nanometer-sized grains. Therefore, we propose a novel scenario for rocky planetesimal formation in which nanometer-sized silicate grains are produced by evaporation and recondensation events in early solar nebula, and rocky planetesimals are formed via aggregation of these nanograins. We reveal that silicate nanograins can grow into rocky planetesimals via direct aggregation without catastrophic fragmentation and serious radial drift, and our results provide a suitable condition for protoplanet formation in our solar system.