Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Monday, March 02, 2009




Other Worlds

This Thursday, just down the road from here a few miles away, the Kepler spacecraft will launch toward orbit on a mission specifically designed to search for Earths in the habitable zone of other stars.

When I was in high school, the science textbook we used said there were nine known planets – period. Since that time, in our own own solar system, we have discovered more than a handful of others, such as the very distant Sedna orbiting more than twice the distance from the sun as Pluto with a single solar year lasting up to 12,000 years and a surface temperature hovering just above absolute zero. There are others.

But as the Kepler spacecraft will look outward to other star systems, it will begin to add to the catalogue of more than 340 extrasolar planets we have also, relatively recently discovered. Here is an example of the catalogue description of the extrasolar planet, Gliese 581C:

Gliese 581 C marked a milestone in the search for worlds beyond our solar system. It is the smallest exoplanet ever detected, and the first to lie within the habitable zone of its parent star, thus raising the possibility that its surface could sustain liquid water, or even life. It is 50 percent bigger and 5 times more massive than Earth.

After a successful Kepler mission, there should be many more such as these added to our catalogue of known planets as the mission is designed ot examine more than 100,000 candidate star systems simultaneously.

Finally – the most remarkable thing about all this is that in today’s classrooms, there is a catalogue of planets much larger than the textbook I used that made relative brief mention of only nine!