G8_ Are We Alone?_Approaching_02

“Are we alone?” is a question many of us contemplate as we investigate the vast darkness of space. To quote the late great Dr. Carl Sagan, “The universe is a pretty big place. If it’s just us, seems like an awful waste of space.” It is this very vastness of space that limits our knowledge of the universe.

In 1969, Neil Armstrong and Buzz Aldrin landed on the Moon. Imagine how the nation felt as it watched the event on live television. They watched in awe as Neil Armstrong climbed down the ladder from the Lunar lander, the Eagle. As his foot hit the ground, he made his now famous statement, “One small step for man, one giant leap for mankind.” The signal was beamed back to Earth to be broadcast across the nation. That same signal also radiated off into space. Traveling at the speed of light, they start their journey out into space. 

Television transmissions, like radio waves, are a kind of electromagnetic radiation. These transmissions move at the speed of light. The speed of light is approximately 300,000 km per second. At that speed, a beam of light could go around Earth at the equator more than seven times in a second. However, compared to the vastness of outer space, a beam of light travels a very short distance.

In fact, if the Sun were somehow turned off, we wouldn’t know for eight minutes. That’s how long it takes for light to travel from the Sun to Earth. It takes almost two years for light to reach the Oort Cloud. The Oort Cloud is a collection of dormant comets at the limits of our own solar system.