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# The cumulative number of known asteroids and the yearly discovery rate are plotted above. The surveys responsible for spikes in detection are marked, the Palomar- Leiden (P-L), Trojan (T-1, T-2, T-3), Spacewatch, and LINEAR. Recent years have seen an explosion in asteroid discoveries due to automated telescopic surveys with advanced detection algorithms. By the year 2015, nearly 700,000 asteroids have been discovered.

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The past decade has brought major improvements in large-scale asteroid discovery and characterization with over half a million known asteroids and over 100,000 with some measurement of physical characterization. This explosion of data has allowed us to create a new global picture of the Main Asteroid Belt. Put in context with meteorite measurements...

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... 3. The distribution of asteroid classes by mass in distinct size ranges and distances from the sun. Asteroid mass is grouped according to objects within four size ranges, with diameters of 100–1,000 km, 50–100 km, 20–50 km and 5–20 km. Seven zones are defined as in Fig. 1: Hungaria, inner belt, middle belt, outer belt, Cybele, Hilda and Trojan. The total mass of each zone at each size is labeled and the pie charts mark the fractional mass contribution of each unique spectral class of asteroid. The total mass of Hildas and Trojans are underestimated because of discovery incompleteness. The top row is consistent with results from Gradie & Tedesco 1982 and Gradie et al ., 1989. The figure is from DeMeo & Carry 2014.  ...

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