How big a crator...?

Question

Assuming that it survives re-entry, how big a crator would a human leave when it impacted with Earth?

I'm not that morbid - it's just a story I'm working on.

Answer 1

Not very big. The terminal velocity of a human falling through the Earth's atmosphere is on the order of 50-60 meters/second (see first source).

You can use the on-line cratering-diameter calculator at the second source to calculate the crater diameter for impactors and impact surfaces of various kinds.

Using a density for a human as 1000kg/m^3 (same as water), a diameter of 0.56 meters (which would be the diameter of a sphere weighing 200 lbs that has the same density of water), an impact velocity of 60 m/s = 0.06 km/s that hits loose sand with a bulk density of 1500 kg/m^3, this calculator predicts a crater with a rim-to-rim diameter of 2.55 meters.

Fun fact: The body would impact with a kinetic energy of 3.95 x 10^-11 Megatons. (that's about 4 microtons )

Answer 2

First, it would not survive re-entry at any point. A human body will achieve a terminal velocity in the atmosphere if started from rest. If, as you suggest, the body has a much higher velocity, it will just slow down to the terminal velocity. If the initial velocity is to high, it will burn up.

So, at a terminal velocity of ~120 mph, a human body will not make much of a crater. That depends of course on the material that the body impacts. If it is a vast pool of whipped cream, the crater would be large. If it is a slab of concrete, there will be no crater.

If you are asking about a free falling human body impacting a planetoid without an atmosphere, you need to provide the mass of the planet and the initial velocity of the body. Under this scenario, say impacting on the moon, a fairly sizable crater could be produced, given a high velocity.

Answer 3

Nowhere near that big -a human-sized object travelling at a typical meteoric speed (25,000 mph) would leave a crater 150-250 feet across, but probably no larger than that. The Earth Impact Database has a good catlaog of impact craters by size.

Answer 4

The flexibility of the human body would force it to have a rather low terminal velocity. IF somehow the human didn't burn up, I think it would just leave an impression roughly its own size and shape and smoosh into the earth.

I think most people who have fallen out of planes have reached terminal velocity and won't go much faster at they just smoosh into the earth and leave little or no impact crater based on the hardness of the Earth.

Answer 5

depends. first, you would have to know the weight of the object on impact. also, the speed on impact. the speed times the weight would tell the force created by the impact. if you knew how much earth that certain amount of force would displace, you could tell the relative depth and width of the crater. also, i have been wondering if a human shape would cause the crater's shape to be irregular...

Answer 6

It all depends upon the density of what the body is impacting into. The body is not that dense compared to most planetary matter. But, that whole whipped cream thing would be fun to watch.

Answer 7

I'd say...depending on the actual size....i mean..if its as big as rhode island maybe the size of maine.....ya know what i mean?

Answer 8

that would depend on the size and velocity of the meteor.