Asteroids

Some asteroid fragments are large enough to not completely burn up in the atmosphere and they end up on the surface of the Earth. It is possible for such a fragment to be radioactive. What is the chief cause of radioactivity? If you had a radiation detector that could measure the amount of radiationâ€”but not the type of radiationâ€”how could you determine which type of radiation was being emitted?

Conservation of energy tells us that energy cannot be created or destroyed. Clearly, energy is required for radioactivity to occur. Where is this energy coming from?

How could the age of this fragment be determined?

Asteroids can be classified into two broad groups based on their composition and location: carbon-rich asteroids dominate the outer part of the asteroid belt, whereas metal-rich asteroids dominate the inner part of the belt. Analysis of the fragment we have discussed in this project reveals that it contains nearly equal amounts of metals and carbon. Can we conclude that the original asteroid had a similar composition? Form a hypothesis about the origin of this asteroid based on the available information.

As mentioned before, our asteroid is in the shape of a sphere and has a mass of 1000 kilograms. Determine the density (in grams per cubic centimeter) of this asteroid if its diameter is known to be 1.2 meters. Useful information: 1 kg = 1000 g, 1 m = 100 cm, volume of sphere = 4/3 p r3. Remember that the radius of a sphere is equal to half its diameter! Show all of your work.

How does your calculated density (in grams per cubic centimeter) compare to the density of water? Would you expect this asteroid to float or sink in water based on your calculations?

One side of our asteroid is constantly illuminated by the Sun while the other side remains in the dark. Do you expect there to be a temperature difference between the light and dark sides? Explain why or why not. If the two sides are at different temperatures, how might heat transfer from one side to the other? Note that our asteroid does not have enough gravity to hold an atmosphere.

Occasionally an asteroid will break into fragments due to a collision. These fragments can leave the asteroid belt and some even make their way to Earth. Upon entering the Earth’s atmosphere, a fragment is heated to high temperature by frictional forces. What would happen to any water-ice contained within a fragment? Is this type of change considered a chemical change or a physical change? Explain.

Asteroids are mainly composed of metals like iron and nonmetals like carbon. Briefly explain the differences between metals and nonmetals based on your knowledge of the periodic table.

If the asteroid fragment contains carbon, it may burn when entering the Earth’s atmosphere. What is the most likely compound to result from this process? Which type of chemical bond would result from this process? Of the two broad classes of chemical reactions mentioned in this course, which type would this be? Be sure to fully explain all of your answers.

Due to friction with the Earth’s atmosphere, a large static electric charge could build up on our plummeting asteroid fragment. Would you expect our fragment to generate a magnetic field? Explain why or why not.

As the fragment falls through the atmosphere, it is heated and some of the material is vaporized. Explain how you could determine the composition of this hot vaporized material from the light it emits.