We estimate the projectile had a diameter of about 0.7 mile (1.1 km) and a mean density about 30 percent greater than water (1.3 g/cm3
). It entered Earth's atmosphere at a speed of 27,000 miles per hour (43,000 km/h) and broke up at an altitude of 43 miles (70 km). The main mass of the projectile struck the ground at 2,200 miles per hour (3,500 km/h), releasing an amount of energy equivalent to 106 million tons of TNT. Based on the size distribution of the craters — the larger ones are in the southern part of the field, the smaller ones in the northern part — we conclude the meteoroid came out of the northeast and moved southwest. Multiple fragmentation events may account for the cratered area's large size.
What would people on the ground have experienced? About 2 seconds after the strike, people 6 miles (10 km) away would have felt the ground shake as it would in a magnitude 6.0 earthquake. The air blast, arriving 30 seconds after impact, would have swept through at a speed of 500 miles per hour (800 km/h) and produced a peak pressure of about 1.4 atmospheres (142,000 Pa), easily collapsing buildings, especially wooden ones. Even from 10 km away, sound from the impact would have reached 103 decibels — loud enough to cause strong ear pain. Up to 90 percent of the trees would have blown over; the rest would have lost their branches.
We found a thin layer of ash in and between the craters. The forest beneath the blast would have ignited suddenly, burning until the impact's blast wave shut down the conflagration. Dust may have been blown into the stratosphere, where it would have been transported around the globe easily, so it may be possible to trace the event in ice cores from Greenland or Antarctica.
In any case, the impact undoubtedly had a major effect on the environment and people then living in the vicinity of Altötting-Chiemgau. The region must have been devastated for decades. We are currently looking for gaps in the historical and archaeological records during the time we propose for the impact to better understand both the event itself and its cultural effects.