Thursday, October 7, 2010

I CALL IT "NEW NEW CAPRICA": Scientists just1 started a comprehensive search for planets similar to Earth, and just like that, lickety-Carnegie-split2, they found one. It's called Gliese 581g. They found it so fast, in fact, that they're estimating that one out of every ten stars may have an Earth-like planet.3 The conversation went like this:
Smart Person: Let's look for planets!
Other Smart Person: Great idea! I'll get started right aw...
Third Smart Person4: Found one!
Some cool things about Gliese 581g, assuming (perhaps overly optimistically) that it has water:
  • The same side faces the sun all the time. So everybody can choose to live in the "twilight zone" -- the part of the planet where it's not superhot or supercold, and where it's always basically dusk.
  • This would make solar power really efficient.
  • It would also mean that you could mow your lawn any time of the day.
  • Sentient beings from Gliese 581g would find our alternating day and night terrifying, or downright inconvenient.
  • It's three times as big as Earth, so everybody can have a yard.
  • It has a 37-day orbit, meaning that the Summer Olympics would happen every 148 days.
Some not great things about Gliese 581g:
  • It's three times the mass of earth, so walking up stairs would be murder.
  • Might not have water, or might be an uninhabitable planet made of sulphur-smelling gas.
Is it just me, or is your first reaction to learning of a possibly inhabitable planet in a distant solar system, "how soon can I get there?"5

1Just" is in astronomical units of time, roughly translating to 10 earth years.
2Astronomy pun.
3Based on a sample size of ten stars surveyed and one Earth-like planet found. Results may not be statistically significant.
4After pause of 10 years during which other Smart Persons invented Facebook, Twitter, skinny jeans, Pinkberry, and Plants vs. Zombies.
5Approximately 20.5 years, assuming that you are a beam of light; longer if you are not.


  1. Meghan4:54 PM

    So hard to talk about how quickly I can relocate to an Earth-like planet without violating the no-politics rule. 

  2. Joseph J. Finn5:53 PM

    Actually, the surface gravity would not be that much more than Earth; yes, it's three times the mass, but it's also three times the size.  Surface gravity is the mass in multiples of Earth (a minimum of 3.1 here) divided by multiples of Earth's radius (a minimum of 1.3), meaning the minimum estimated gravity would be 2.3 gs.  Heavy (I, at 175 lbs, would be 402 there) but no unendurable.  Of course, it all depends on further observation and whether it's a rocky or more watery world (the rockier, the higher the density, the higher the gravity).

    Note that I may have missed a factor here; I've also seen numbers floating around with sub-2 gs.

  3. isaac_spaceman6:21 PM

    If I suddenly had to carry en extra 225 pounds (a whole NFL running back) everywhere I went, I'm quite sure I would use the word "unendurable." 

  4. Anonymous7:33 PM

    I think in planetary terms, unendurable would "unable to move". Or "flattened into a pancake."

  5. DonBoy7:59 PM

    It would also mean that you could mow your lawn any time of the day.

    Sentient lawns don't like to be mowed.

  6. spaceboy 2.08:31 PM

    I never thought that would happen.

  7. I'm holding out for an earth-like planet that will provide me with a net subjective weight loss.

  8. Robin7:22 AM

    I like footnotes!

  9. Mr. Cosmo1:09 PM

    Where are you getting that it's 3 times the size?  I thought it was found through orbit perturbation analysis -- does that give any indication of size? 
    My recollection is that Earth is unusually dense for a planet, since a lot of the lighter silicas were blasted off in the collision that formed the moon.