I used the Computing Effects of an Impact on Earth website to learn what would happen if I, Toren Atkinson, fell to Earth – or the closest I could come to such.
Distance from Impact: 1.00 km = 0.62 miles (Is this where I fall from or where you are watching from? The former, I think)
Projectile Diameter: 1.00 m = 3.28 ft = 0.00 miles (I’m two meters tall but obviously I don’t have a diameter of even 1m. So I’m cheating a bit, but that’s the minimum value I could enter. Just imagine me curled up in a phoetal position and fattened up on Thanksgiving dinner when I fall. I do love being called a projectile.
Projectile Density: 500 kg/m3 (This is about half the density of ice. I guessed. I don’t really know what my density is.)
Impact Velocity: 15.00 km/s = 9.31 miles/s (11 is minimum, So I figure 15 is decent.) Impact Angle: 90 degrees (straight on – the best way.)
Target Density: 1000 kg/m3 Target Type: Liquid Water of depth 1.00 meters, over typical rock. (I imagine myself falling into Chris Woods’ kiddie pool.)
Energy:Energy before atmospheric entry: 2.95 x 1010 Joules = 0.70 x 10-5 MegaTons TNT. The average interval between impacts of this size somewhere on Earth is less than 1 month. (Think about that!)]
The projectile begins to breakup at an altitude of 89300 meters = 293000 ft (“I regret nothing!” you hear me cry). The projectile bursts into a cloud of fragments at an altitude of 72700 meters = 239000 ft (I’m so beautiful!). The residual velocity of the projectile fragments after the burst is 14.3 km/s = 8.86 miles/s
The energy of the airburst is 2.78 x 109 Joules = 0.66 x 10-6 MegaTons. No crater is formed, although large fragments may strike the surface. (Watch out for hot flying junk)
Major Global Changes:The Earth is not strongly disturbed by the impact and loses negligible mass. (Negligible mass? How dare they!) The impact does not make a noticeable change in the Earth’s rotation period or the tilt of its axis. The impact does not shift the Earth’s orbit noticeably. (Not literally, but metaphorically, watch out.)
Air Blast:The air blast at this location would not be noticed. (The overpressure is less than 1 Pa) (I.E. no Toren shock wave).
And if I was 500 miles across, I might look like this (7 minute video which according to astronomer Phil Plaitt is pretty accurate). http://www.youtube.com/watch?v=yYgEwXWilUc