Another Mind-Blowing Conversation

Periodically, my neighbor, Paul Gilster, and I have coffee together at Starbucks.  Paul is the author of Digital Literacy, and several of the earliest books about the Internet, including the Internet Navigator and the Mosaic Navigator.  Most recently, Gilster wrote Centauri Dreams, a fascinating (mind-blowing) book about the future of interstellar space travel.  He also maintains a blog by the same name, which is a daily visit for the astronomy and advanced propulsion communities.

Last week, Paul suggested that we may well get evidence of life on planets outside the solar system before we know anything about life on the other planets of our Sun.  Conservatively speaking, he said that we should have technology within 20 years to take spectroscopic readings of the atmospheres of known planets and the more terrestrial worlds we will soon be discovering.  (I was surprised to learn that 246 extrasolar planets have been discovered orbiting 98 stars.  NASA runs a database of discovered planet, non-solar planets at PlanetQuest.)  Paul suggested that if we decided to fully fund the development of these technologies, we could be collecting readings in as little as ten years..

There are certainly elements and combinations of elements that can only be produced in significant quantities by bio-metabolism.   According to an article that Paul sent me that night,

“The most convincing spectroscopic evidence for life as we know it is the simultaneous detection of large amounts of oxygen as well as a reduced gas, such as methane or nitrous oxide, which can be produced by living organisms. Oxygen, methane, and nitrous oxide are produced in large amounts by plants, animals, and bacteria on Earth today, and they are orders of magnitude out of thermodynamic equilibrium with each other.”1

Another article suggests that oxygen alone may indicate life…

“Once created, molecular oxygen may combine with other molecules in the process of oxidation, and thus disappear as a spectral signature unless it is continually replenished by further photosynthesis.2

In his follow-up e-mail, Paul urged that such evidence would not be airtight, “but it will be persuasive and convincing.”

Why do I care?  Because I remember a time before humankind had entered space.  I remember Sputnik and Echo.  I remember Gagarin and Shepard.  I remember when the world watch a man walk on the moon.  I remember the launch of the first Space Shuttle, our first spaceship, and am continually astounded by our robotic explorations of our own solar system.

I remember a time when we were accountable to more than just ourselves — when we were accountable to possibilities.  Our children well be so fortunate if they live in such times — if they can make such times.