Investigate the effects of an asteroid impact on Earth through a small-scale simulation.

Name: Alex Hamilton

Date Started: 30th March 2003

Physics Coursework – Asteroid Collision With The Earth

Experiment

To investigate the effects of an asteroid impact on Earth through a small-scale simulation. I shall be measuring the depth of the crater caused by a steel ball bearing being dropped from different heights into sand.

I shall be dropping a steel ball into sand to simulate an asteroid collision, because the asteroid would be roughly spherical and have a high density, like the steel ball. The sand will react similarly to how the Earth would if impacted on.

Planning

An asteroid, also called minor planet, or planetoid, is any one of a host of small rocky astronomical objects found primarily between the orbits of Mars and Jupiter. By the 1990s, more than 7,000 asteroids had been observed at two or more oppositions, and 5,000 of them had been assigned numbers, which is done as soon as accurate orbital elements have been determined.

Asteroids whose orbits cross that of the Earth on a nearly continuous basis are called Apollo asteroids. About 91 of these asteroids have definitely been identified. Some astronomers would like to mount a full-scale search for such asteroids, partly out of a fear that they may collide with the Earth.

Collisions with larger asteroids are rare, but smaller ones are more numerous. It is estimated that a few asteroids with a diameter of 1 km (0.6 mile) may collide with the Earth within a period of 1,000,000 years. If an asteroid of this size were to collide with the Earth, it would produce an explosion with as much force as several hydrogen bombs.

A short-term disturbance in the world's climate could result, and a collision in the ocean could be catastrophic. Some investigators believe that the extinction of the dinosaurs and many other land and marine animals at the end of the Cretaceous Period (about 65 million years ago) was triggered by the impact just north of the Yucatan Peninsula of an asteroid or meteorite measuring some 10 km (6 miles) in diameter.

(Information provided by Encyclopaedia Britannica)

The potential damage an asteroid colliding with the Earth can cause is dependant on a number of variables. The mass of the asteroid, as the greater this is the larger the impact area; the asteroid’s velocity, as the faster an object collides with something, the more energy is transferred. Both the mass and velocity determine the momentum and thus kinetic energy that the asteroid has – this is what determines the extent of the damage that its impact would create.

When an asteroid collides with Earth, it loses its velocity. Kinetic energy and momentum are conserved.

Energy present in Earth and Asteroid before collision = Energy present in Earth and Asteroid after collision

As the Earth is much more massive than the asteroid the momentum conserved will change the Earth’s orbit very little and is of no concern – however the effect of the kinetic energy in this totally inelastic is not. As the collision is inelastic the asteroid will impact with the Earth and stay there. This collision will result in a huge amount of debris being thrown into the atmosphere, seismic shockwaves travelling through the Earth causing damages to structures and of course anything within the area of impact will be completely annihilated

The conservation of Kinetic energy law applies ...