Please note: the results below are estimates based on current (limited) understanding of the impact process and come with large uncertainties; they should be used with caution, particularly in the case of peculiar input parameters. All values are given to three significant figures but this does not reflect the precision of the estimate. For more information about the uncertainty associated with our calculations and a full discussion of this program, please refer to this article
- Distance from Impact: 100.00 meters ( = 328.00 feet )
- Projectile diameter: 20.00 meters ( = 65.60 feet )
- Projectile Density: 8000 kg/m3
- Impact Velocity: 20.00 km per second ( = 12.40 miles per second )
- Impact Angle: 90 degrees
- Target Density: 2500 kg/m3
- Target Type: Sedimentary Rock
- Energy before atmospheric entry: 6.70 x 1015 Joules = 1.60 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth is 169.6 years
Major Global Changes:
- The Earth is not strongly disturbed by the impact and loses negligible mass.
- The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).
- The impact does not shift the Earth's orbit noticeably.
- The projectile begins to breakup at an altitude of 16700 meters = 54900 ft
- The projectile bursts into a cloud of fragments at an altitude of 1700 meters = 5570 ft
- The residual velocity of the projectile fragments after the burst is 6.91 km/s = 4.29 miles/s
- The energy of the airburst is 5.90 x 1015 Joules = 1.41 x 100 MegaTons.
- Large fragments strike the surface and may create a crater strewn field. A more careful treatment of atmospheric entry is required to accurately estimate the size-frequency distribution of meteoroid fragments and predict the number and size of craters formed.
- What does this mean?
The air blast will arrive approximately 5.16 seconds after impact.
- Peak Overpressure: 732000 - 1.46e+06 Pa = 7.32 - 14.6 bars = 104 - 208 psi
- Max wind velocity: 640 m/s = 1430 mph
- Sound Intensity: 117 dB (May cause ear pain)
- Damage Description:
Multistory wall-bearing buildings will collapse.
Wood frame buildings will almost completely collapse.
Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.
Highway truss bridges will collapse.
Highway girder bridges will collapse.
Glass windows may shatter.
Glass windows will shatter.
Cars and trucks will be largely displaced and grossly distorted and will require rebuilding before use.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.
Tell me more...
Click here for a pdf document that details the observations, assumptions, and equations upon which this program is based. It
describes our approach to quantifying the important impact processes that might affect the people, buildings, and landscape in the
vicinity of an impact event and discusses the uncertainty in our predictions. The processes included are: atmospheric entry, impact
crater formation, fireball expansion and thermal radiation, ejecta deposition, seismic shaking, and the propagation of the atmospheric
Earth Impact Effects Program Copyright 2004, Robert Marcus, H.J. Melosh, and G.S. Collins
These results come with ABSOLUTELY NO WARRANTY