UFOs (Unidentified Flying Objects) are in the news again. But it is high time that our media stop speculating that alien spaceships may have been sighted. Such sightings are impossible! In science, it is dangerous to use a word like “impossible,” but this article shows that this is the appropriate way to characterize visiting alien spaceships.

The proof is based on a simple equation. That makes it out-of-bounds for the brand of material published in the Op-Ed pages of *The New York Times*, but it is appropriate for the less restrictive Skeptical Briefs.

Equations shouldn’t be ridiculed; after all, editors—and people in general—have become accustomed to another simple equation: E=mc^{2}. How did scientists manage to sneak E=mc^{2} into the public domain? That equation has been around since 1905, but the specter of insufficient *energy* has recently shown its face, so the public is paying attention now.

It is amazing that one can get a tremendous amount of energy from a small amount of uranium. The explanation is that c^{2} (the speed of light squared) is a huge number—approximately 1 x 10^{17} (meters/second) squared. So even a small amount of mass (m) multiplied by 1 x 10^{17} can supply an awful lot of energy. The famous equation will soon be in the headlines again as the United States plans and constructs many nuclear power plants to decrease our dependence on oil from the countries that breed suicide bombers.

Al Gore, Thomas Friedman, and other harbingers of doom are rightly urging us to start thinking about energy. In line with this, our media editors should get acquainted with this UFO-related equation: E=m v^{2}/2. Admittedly, it is a bit more complicated than E=mc^{2} but well within the capabilities of an intelligent layperson.

What does E=m v^{2}/2 mean? The E stands for kinetic energy—the energy required to lift a spaceship, or any flying object, into its orbit. Here is why visiting alien spaceships are an impossible nightmare for most people (or a dream for UFO enthusiasts): if one substitutes realistic values for m and v in the equation and does the arithmetic, she’ll find that E is so huge that it is beyond belief. The distances in outer space are so vast that the velocity of a space vehicle has to be one-tenth the speed of light if it is expected to reach Earth in a reasonable period of time. That means that v^{2}/2 is around 1 x 10^{14}.

What about m (mass)? Well, the Mars Lander—in which a crew could live for 260 days—weighs 130 metric tons. An alien spaceship, even with small creatures, would have to weigh at least 200 metric tons (200,000 kilograms). After all, it has to carry its own fuel (surprise)! Substituting the numbers, we get E=1 x 10^{20} (watt-seconds).

So what does that mean if we offer a layman’s explanation? The entire capacity of the United States power system is one trillion watts (1 x 10^{12}). If we could by some magic harness the *entire* output of the U.S. power system behind a space vehicle, it would take 1 x 10^{8} seconds—*three years*—to get it up to speed!

So, that UFO that was sighted by several reliable witnesses had a three-year shove by the equivalent of the entire U.S. output. Can you believe it? The UFO enthusiasts simply retort with: “They come from a superior civilization. They can *somehow* do it.” That’s the most nonsensical idea ever launched. The laws of physics and chemistry are the same everywhere in the universe.

So the next time somebody claims to have spotted a spaceship, your response should be “I agree that you saw something, but it could not possibly be an alien spacecraft.”