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Every since human beings have been gazing up at the stars, we have wondered whether there are other living creatures out there. Ancient humans often believed that the gods resided above us, and the stars and constellations they formed became part of a living, divine cosmos of which earth was an integral part. Specific beliefs varied from culture to culture. The Mongolians had one of the simplest names - they called it the “Great Blue Sky.” When Genghis Khan needed to win a battle, or the lowliest nomad had to find his herd, it was to the “Great Blue Sky” over the Mongolian countryside that they turned to for help.

As science began to take hold, and Galileo established that we were not necessarily the center of the visible universe, things began to change. The further we looked, the colder it got. We discovered that there were not just thousands upon thousands of stars out there. There were millions. Those that we did see where only part of one galaxy, our own, which we called “the Milky Way.” Then we discovered that there were many such galaxies out there, hundreds of millions in fact, each with a billion or more stars! The Coma Cluster (first image, above), for example, includes about 1,000 galaxies! It is one of the densest such clusters. NGC 6217(second image, above) is a spiral galaxy (much like our own) which reveals the incredible beauty of these objects. It is about 60 million light years away and about 30,000 light years across. Could there not be a sprinkle of life in its dusty arms?

Yet the more we explored the universe, the less hospitable it seemed to life. Earth, we learned, is just the right distance from the sun to support the diversity on our planet. A little closer and we would roast. A little farther and we would freeze. As we sent spacecraft to other planets in our own solar system, we found them to lack the oxygen and carbon molecules, the atmosphere, gravity and other ingredients apparently necessary to life as we know it. As we turned our telescopes in search of planets around other stars, those we did discover seemed to be unlikely candidates for life. They were too small or large, too unlike the only planet we know that actually has so much life. The tremendous forces we see unleashed across the universe, for example in the colliding galactic cluster spewing X-rays known as Stephan’s Quintet (above), also made us realize how delicate the presence of life is.

Things only seemed to get lonelier.

But we have hardly given up! Indeed, the mystery has only deepened. How could we be the only ones in this vast cosmos? For many scientists, the more enormous the universe is, the higher the probability that somewhere else life has also evolved. It may be different from earthly life, but life nonetheless. We also in recent years have discovered strange forms of life on our planet, deep under the ocean and beneath the planet’s crust. It could be worms living on sulfur, or bacteria that exist in harsh, acidic conditions we never thought possible for survival. These discoveries are increasing the probability that some forms of life have taken hold in other places across the universe, even possibly in our solar system. The problem is that we are not sure. We lack the proof scientists seek. We also have no idea if such life would be intelligent or could communicate with us.

We have not stopped wondering. Our collective attempts to discover life outside earth go by the name Search for Extra-Terrestrial Intelligence (SETI). Once supported by NASA, these efforts are now largely funded by private donations, large and small, from people across the US and abroad who really do want to know. They cannot wait for some alien to drop by and announce themselves. SETI uses radio waves to scan the skies and all those galaxies to see if any intelligent messages or communications are coming from space. To decide whether a message is intelligent, computers are used to process the signals and check whether the data has patterns or other signs of not being the random radio noise emitted by stars and galaxies.

This is a project that everyone can get involved with. The amount of data to be analyzed is enormous, so vast that the project is using distributed computing to process the results. Data sets are being sent to individual home computers which, when they are idle, can be set to process the data and see if there contain signs of intelligent communications. This is like a super-massive computer working at the same time. Results are sent back over the Internet to SETI headquarters in Mountain View, California. Computer users download a program that does this when their computer is in screen-saver mode. You can watch this happening in front of you (screenshot above). A description of the procedure and place to get the software is at the SETI website.

So, if like ancient human beings, you are wondering about what may be out there, here is a chance to turn your wonder into active participation. Who knows, yours might be the computer that finds the answer!