Today on Far Future Horizons we present another fascinating episode from the acclaimed documentary series How the Universe Works concerning exosolar planets (or Exoplanets). Some of these worlds are quite literally Planets from Hell.
Over the last twenty years we have discovered an extraordinary menagerie of planetary exotica outside our own solar system, all of them truly wild worlds, a collection of monstrosities. Now we must face the questions: Is every planet out there a planet from hell? Is the Earth the only habitable world in the universe?
|Planet Gliese 581c Compared to Earth|
This installment of How the Universe Works mentions Gliese 581c which has a Super-Earth at the edge of the habitable zone. This planet may have liquid water at its surface.
|Artist's impression of the planetary system around the red dwarf Gliese 581. Using the instrument HARPS on the ESO 3.6-m telescope, astronomers have uncovered 3 planets, all of relative low-mass: 5, 8 and 15 Earth masses. The five Earth-mass planet (seen in foreground - Gliese 581 c) makes a full orbit around the star in 13 days, the other two in 5 (the blue, Neptunian-like planet - Gliese 581 b) and 84 days (the most remote one, Gliese 581 d).|
According to the latest Kepler statistics there are 50 billion planets in our galaxy and perhaps one percent of them orbit inside the habitable zone of their parent star. That would make a whopping 500 million potentially habitable worlds in our galaxy alone. So perhaps there is some hope yet. Planetary hells are more common in our galaxy but there should still be lots of planetary heavens out there.
How the Universe Works is available on DVD from Amazon Books.