Background
An asteroid about twenty metres across broke apart in the atmosphere over Russia's Chelyabinsk region. The shockwave shattered windows and injured many people, mainly through flying glass. Camera footage, acoustic measurements and meteorite fragments enabled detailed reconstruction of its trajectory and energy. This was an airburst rather than a large crater-forming impact; the map approximately locates the affected area. The event intensified attention to planetary defence.
Sources: NASA — Crucial Data from Meteoroid Impact