G8_ Are We Alone?_Grade level_04

The SETI Project was formed in order to answer three basic questions: “What is life?”, “How does it begin?”, and “Are we alone?” Founded in 1984, the SETI Institute now employs more than 130 scientists, educators, and administrative staff. The optimism that drives the SETI Project is an outcome of the Drake equation. The Drake equation is an algorithm used to estimate the possible numbers of civilizations on other worlds advanced enough to release detectable signs of their existence into space. In other words, as they communicate with each other, similar electromagnetic waves would be released into space. Therefore, it would be possible to intercept those signals, assuming we were listening for them. According to the Drake equation, there may be between 1000 and 100,000,000 civilizations in the Milky Way galaxy alone.

The SETI scientists hope to answer the ultimate question, “Are we alone?” by listening to the skies. Some of their earliest work was using the giant Arecibo radio telescope in Puerto Rico. In 2007, they commissioned to build the Allen Telescope Array (ATA), the world’s only dedicated and purpose-built SETI radio telescope.
Today, the Institute now includes optical laser pulses in its search. This will be accomplished by deploying specialized cameras around the globe for an all-sky, all-the-time observatory. This will enable SETI to search for laser flashes from deep space.

Now consider the other option of sending astronauts out into space to search for other worlds that may or may not contain life. Is this even a viable option, given these great distances? For comparison, what if we could build and launch a spacecraft capable of reaching speeds near 20 percent of the speed of light? This certainly is an ambitious speed to travel even in the vastness of space, where even a collision with a single atom would cause major damage to the craft. A collision with something a little larger, like a speck of dust would be catastrophic to the craft. However, if we could engineer this craft to be safe, how long would it take to reach our nearest neighboring star system, Proxima Centauri? Instead of the 4 years for light, it would take 20 years for an astronaut just to get there. Keep in mind, we don’t have a spacecraft capable of travelling at these speeds, let alone one capable of carrying astronauts safely.

Due to the great distances involved, at least for the time being, there seems to be only one logical option. If we want to answer the question, “Are we alone?” for now, we listen for detectable signs of the existence of other intelligent life. Even if a sign is detected, don’t expect there to be a conversation. Consider those large distances. If we asked a question, how long would we have to wait for an answer?