Scientists have made some tremendous advances in recent years. Biologists are discovering that life is not as delicate as we once thought. No matter where on Earth we look, we seem to encounter life. Hardy bacteria that can thrive in the harshest of conditions. From the extreme heat of thermal springs and deep sea hydrothermal vents to the harsh conditions found in nuclear reactors, bacteria and other microbes find a way to prosper. We have exposed bacteria to the harshness of space on the outside of the international space station, only to discover later that the bacteria hadn’t been killed off, but had survived the exposure and were able to grow again upon return to normal conditions.
Meanwhile astronomers are making more and more discoveries about the world around us. Water seems to be everywhere. We have traced its signature in molecular clouds between the stars and in distant solar systems as they are being born. We suspect it is to be found in vast quantities, below the surface, on some of the moons of Saturn and Jupiter. The number planets that we know of in the universe is growing at a phenomenal rate. And we now suspect billions of Earth like planets in our own galaxy and immeasurable Earth like planets in the universe.
Of course with all this going on, it’s seems logical and tempting to infer that the universe must be teeming with life. Look at the number of planets that exist. Can we really be the only example of life in such a vast universe? As tempting as it is to believe that it is only a matter of time until our cosmic cousins pay us a visit, we should remember that we still know of only one example of life in the universe, and that is here on planet Earth. Speculation on the presence of life elsewhere, is just that, speculation. We are still unsure as to how easy or hard it is for life to get going. Is it common? Is life on earth a once off and a big fluke? We don’t know. We don’t know how life began, where life began and haven’t firmly defined when life began. We haven’t managed to create life in the lab. We haven’t heard signals from other worlds despite listening for decades. There are still a lot of unanswered questions and a lot more discoveries to be made. In the meantime, however, it is fun to imagine just what could be out there.