INVESTIGATION

There

are a few factors that must be calculated when we’re talking about asteroid

impact: impact energy, atmospheric entry, crater dimension, thermal radiation

and seismic effects. For this internal assessment I will be only investigating

two factors, which is the impact energy and crater dimension.

IMPACT ENERGY is the energy required by the object to hit and fracture

another material. In this case, we will investigate the impact energy of the

asteroid towards the earth. The equation is originated from the kinetic energy

()

:

,

which is modified for an asteroid to =

, assuming that the asteroid is a

simple asteroid (spherical-shaped). is

the density of the asteroid, L is the

diameter of the asteroid and is

the velocity of the asteroid.

CRATER DIMENSION is how the ground will be shaped/warped due to the impact of

the asteroid. Because we are calculating a simple asteroid, we are only using

the equations for (a) transient crater (before impact) and (b) simple crater

(after impacts).

The

equation for (a) transient crater is:

Where

based on the figure (a), is the diameter of the transient crater, is

the density of the asteroid, is

the density of the target area (ground or water), L and v is the diameter and

velocity of the asteroid, and g is the constant of earth’s surface gravity. The

sine is what angle the asteroid will be crashing on the earth.

The

equations for (b) simple crater start with measuring the final diameter of the

crater, using the equation:

This

is determined from the previous research done by (Grieve and Garvin 1984) in

Meteor and Brent Crater. We have to acknowledge that there is a thickness in

the breccia lens, which is determined by the equation:

Where

Thus

with all the data from the calculations collected, the final impact of the

crater in (b) simple crater is the sum with this equation:

CALCULATING PAST IMPACT: RIES

CRATER, GERMANY

SPECIFICATIONS

OF RIES ASTEROID

Projectile

Diameter

1500

m

Projectile

Density

Rock

(2700 kg/m3)

Impact

Velocity

20

km/s

Impact

Angle

30

degrees

Target

Type

Crystalline

Rock

CALCULATING

IMPACT ENERGY

= ______ joules

CALCULATING

(a) TRANSIENT CRATER

=

CALCULATING

(b) SIMPLE CRATER

=

=

=

CALCULATING FUTURE IMPACT 99942

APOPHIS

Projectile

Diameter

0.37 km = 320 m

Projectile

Density

Rock

(2,600

kg/m3)

Impact

Velocity

12.6

km/s

Impact

Angle

45

degrees

Target

Type

Crystalline

Rock

As

this asteroid impact is just a prediction, the target type will be the same as

the Reis Impact in Germany, which is crystalline rock, for a better comparison

during the discussion of results.

CALCULATING

IMPACT ENERGY

= ______ joules

CALCULATING

(a) TRANSIENT CRATER

=

CALCULATING

(b) SIMPLE CRATER

=

=

=