209 Planets Found…and Counting
— The Manitoba Planetarium’s Star Theatre;
There’s something very seductive about wondering what other worlds are like. Particularly now that we know they really exist. I can remember my first full-time job – at the Manitoba Planetarium. My job was working as a Summer Observing Program Coordinator (a job I did pretty well, for a 14-year-old if I do say so myself – albeit with the supervision and assistance of others who’d done that job and more for years). But that imagination about what other worlds might be like was further nurtured working in that environment; with people who’s job was to produce education and information programs for the public and foster interest in the field of astronomy.
I held the job for just 3 months; it was a summer job only, unfortunately. But my interest in astornomy never died; nor in space exploration. At the time, I was disappointed to learn that although the popular media seemed to assume planets existed around other stars, the scientific fact had yet to establish this. The best information of the day (summer 1984, to be exact) was that planets existed only in our own solar system; and for all we know other star systems had clouds of dust or gas around them.
It would be 11 more years before the very first extra-solar planet would be discovered – a huge "gas giant" that was very nearly a star in its own right. Only it didn’t have enough mass & gravity to start a fusion reaction at the core – the process that causes a star to ignite. In journals that published and studied the work of the scientists who made the discovery seemed to doubt, even then, whether this discovery really indicated that planets comparable in any way to those we know exist in our own solar system existed elsewhere.
To date, Earth’s scientists have discovered several dozen (209 to be exact) planets around nearby stars. There’s now sufficient evidence to predict that there are, very likely, much smaller – Earth-sized objects around at least some of those stars. Various groups have taken to already calculating the "habitable" zone around these stars and trying to identify whether the gas giants discovered fall inside those zones and, thus, could have a possibility of life-bearing moons. One German website I dsicovered this weekend (cited at the start of this article) summarizes this information for many of the extra-solar planets discovered. It also hypothesizes about what might be found there someday; although in a fashion consistent with currently available data.
In the next four or five years, NASA is expected to launch its "Terrestrial Planet Finder" array. This array of orbital telescopes (and other equipment) will be specifically tasked with doing a survey of nearby stars for smaller, Earth-sized planets, capable of supporting life. Of course, the main question all this research is aimed at answering is the age old "Are we alone?" When such smaller bodies can be observed, will there be technologically advanced civilizaitons discovered also?
I couldn’t have imagined that such discoveries could be made in my lifetime because, at the time I worked at the Planetarium, I’d thought we’d have to wait until our propulsion technology advanced to a point where we could send probes there. Since such discoveries would require a revolutionary understanding about such things as particle physics and gravity, coupled with enough time for that resarch to result in meaningful technology being produced for probes or vessels to travel the distance between stars in my lifetime – well suffice it to say I’d expected it to take centuries to answer the question.
It’s encouraging to think that it might not be. I still don’t expect we’ll be able to necessarily communicate with alien species in my lifetime as is the norm in such fictions as Star Trek or other sci-fi movies. But the question – are we alone? – seems to be on the brink of having some kind of answer, perhaps expressed only as a liklihood.
A particularly exciting notion – one childhood fantasy, at last, realized.