In search of another Earth

Natural History, July-August, 2002 by Robert (American businessman and engineer) Anderson

One of the enduring themes of science fiction is the discovery of a distant Earth-like planet. You know, a hospitable place where humanity could get a fresh start and perhaps even create a utopia. Such fantasies may soon have a grounding in reality, as I learned at NASA'S "Planet Quest" Web site (planetquest.jpl.nasa.gov/). At the time of my visit, the number of planets discovered outside our solar system stood at seventy-six, with the newest addition circling the star HD 136118.

I clicked on "New Worlds Atlas" to check out possible alternatives to our own planet. You can search the list by selecting a variable, such as planets with host stars visible to the naked eye (which is nice, because you can go right outside and look at them), or a planet type: gas giant, hot Jupiter, or terrestrial (more or less Earth-like). I clicked on the latter and ... zero. Apparently, we still lack the means to detect planets as small as our own.

But all that is about to change. The site lists a number of future NASA missions designed to increase our chances of finding alien worlds. The new technologies are impressive. One of them is a fleet of space telescopes flying in precise formation; the net effect will be equivalent to an enormous eye, capable of detecting smaller planets. I'll bet that within a decade we'll have a few worlds in the terrestrial category to dream about. Then the only problem will be how to get there. Currently, the closest planet in the "New Worlds Atlas" is 10.4 years away--that is, if we're traveling at the speed of light.

Robert Anderson is a freelance science writer living in Los Angeles.