Who's out there? It's all in the stars
By Amanda Jermyn

Reach for the StarsÖ Amanda Jermyn January 2011

Last month I wrote about the search for life elsewhere in the universe, but if weíre lucky enough to find life somewhere out there, will we recognize it as such? Here on earth we think we know life when we see it, but what exactly is it? In biology, living organisms are defined as having the capacity to grow, to respond to stimuli, to reproduce, and to adapt to their environment over successive generations. Might there be untold ways of doing this?

Six chemical elements have long been thought essential for life: carbon, oxygen, nitrogen, hydrogen, sulfur and phosphorus. However, NASA astrobiologist Dr. Felisa Wolfe-Simon recently demonstrated that bacteria from Mono Lake in California could be trained to live on a diet of arsenic, gradually exchanging atoms of phosphorus in their bodies for atoms of arsenic. Life, it seems, is full of surprises, and may not require specific elements to exist. We also know that some forms of life exist in the extreme cold of Antarctica, others in extreme heat. It was once thought that no creatures could survive the harsh combination of high temperatures, toxic chemicals, complete darkness and high pressure of hydrothermal vents on the ocean floor, but we now know that a variety of bizarre organisms, including giant tube worms, thrive there. Almost two miles beneath the surface of the earth, in a South African gold mine, there exists a bacterium that lives in complete darkness, with no oxygen, in 140 degree Fahrenheit heat. These adaptations suggest that, even here on earth, life is highly flexible, and that undiscovered species could take on forms we canít even begin to imagine. How much more so could this be in the alien environments of space?

The more we find out about our universe the more likely it seems that life exists out there. Until recently it was thought that life would most likely be found on planets orbiting stars like our own. Yet up to 90% of stars in the universe are the dimmer, smaller red dwarfs, and it is now thought that many of these could sustain life too. And life need not be limited to planets. Jupiterís moon Europa appears to have an ocean of liquid water beneath its frozen surface that might sustain life, and Saturnís moon Titan, with its methane and abundant organic chemicals, is another contender. Just last month Yale astronomer Pieter van Dokkum raised the estimate of the number of stars in the universe threefold to a mind-boggling 300 sextillion (3 followed by 23 zeros), increasing the chances of life somewhere among them. As we discover more diverse life forms, we are forced to expand our definition of life, and along with it, the possible places in the universe where it may prosper.

This month join the Springfield STARS Club for a series of short talks by club members Jack Megas, Alan Rifkin, David Wexler, Adam Jermyn and Kevin Kopchynski on Our Changing Perception of the Universe. These talks aim to give a brief introduction to Creation Myths, The Big Bang, General Relativity, Special Relativity, String Theory, and our current view of the Milky Way Galaxy. The evening will conclude with a question and answer session with all participants. This series of short talks will take place on Tuesday, January 25th at 7:30pm at the Springfield Science Museum at the Quadrangle. Refreshments will be served, and the public is welcome free of charge.