Glaser's "Chemistry is in the News"
To Accompany Wade Organic Chemistry 4/e.
Chapter 11. Reactions of Alcohols

Editorial Comments

The fear of global devastation has recently surged due to the movies such as "Deep Impact" and "Armageddon," in which an asteroid threatens to collide with the Earth. Is there a chance these scenarios will occur? According to the article, the answer is absolutely. A few years ago, such an idea would have been ridiculed, now however, the possibility is being taken quite seriously by agencies such as NASA.

It is important to understand the scale of the damage inflicted upon the Earth should a comet hit. In order to do so, we need a method of comparing the damage of the impact to the damage done by common and well-known explosives. The standard measurement of energy is the kilocalorie. This energy is the energy required to heat one liter of water one degree Celsius. TNT (dynamite) is so powerful that it is used for such immense jobs as blowing up mountains for roads. It releases more than a million kcal per ton. The first atomic bomb dropped in WWII was the equivalent of 13,000 tons of TNT. A small asteroid, say one kilometer in diameter, would cause the damage equal to 300 Gigatons of TNT. That's nearly 250 million times more powerful than the bomb dropped on Hiroshima!

The damage caused by the collision would not be limited to strength of the explosion, but also by its aftereffects. There might be tsunamis, firestorms, acid rain, and more. There might also be ramifications similar to a nuclear winter. In that scenario, large quantities of dust particles would be scattered into the atmosphere, which would block out most of the sun's rays. It would be impossible to see two feet in front of you for months. The visible and UV portions of the electromagnetic spectrum given off by the sun would be blocked, obstructing plants' ability to perform photosynthesis. Without photosynthesis, the planet's oxygen and food supply would shortly be depleted, and virtually all life would end.

For an idea of what an asteroid collision would look like, check out our picture gallery.

Questions

Question 1: What are the odds of a large asteroid or comet hitting the Earth?

Question 2: What is it about the structure of TNT that makes it so devastating?

Question 3: An example of a comet nearly hitting the earth is the close encounter with Hale-Bopp. How close did the comet Hale-Bopp come to the Earth?

Question 4: What is the range of wavelengths of visible light?

Question 5: What steps should mankind take in preparation for an asteroid collision?