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
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Your Inputs:
- Distance from Impact: 10.00 km ( = 6.21 miles )
- Projectile diameter: 20.00 meters ( = 65.60 feet )
- Projectile Density: 8000 kg/m3
- Impact Velocity: 17.00 km per second ( = 10.60 miles per second )
- Impact Angle: 45 degrees
- Target Density: 2500 kg/m3
- Target Type: Sedimentary Rock
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Energy:
- Energy before atmospheric entry: 4.84 x 1015 Joules = 1.16 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth is 169.6 years
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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.
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Atmospheric Entry:
- The projectile begins to breakup at an altitude of 14100 meters = 46100 ft
- The projectile bursts into a cloud of fragments at an altitude of 3520 meters = 11500 ft
- The residual velocity of the projectile fragments after the burst is 6.28 km/s = 3.9 miles/s
- The energy of the airburst is 4.18 x 1015 Joules = 1.00 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.
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Air Blast:
- What does this mean?
The air blast will arrive approximately 32.1 seconds after impact.- Peak Overpressure: 22300 - 44500 Pa = 0.223 - 0.445 bars = 3.16 - 6.32 psi
- Max wind velocity: 48.1 m/s = 108 mph
- Sound Intensity: 87 dB (Loud as heavy traffic)
- Damage Description:
Glass windows will shatter.
About 30 percent of trees blown down; remainder have some branches and leaves blown off.
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
blast wave.
Recent improvements in the airblast calculation are described here.
Earth Impact Effects Program Copyright 2004, Robert Marcus, H.J. Melosh, and G.S. Collins
These results come with ABSOLUTELY NO WARRANTY