NP - That Golgilocks Planet

[David Morris]

http://io9.com/5653433/the-astrophysicist-who-discovered-zarmina-describes-life-on-second-earth

So this planet is bigger and more massive than Earth. Would the
gravity there be too much for a human colony?

That's what's interesting – the gravity wouldn't be too much. It's
three to four times the mass of Earth but 20-50% bigger. So there's
more real estate there. The gravity would feel very similar to Earth -
you'd be about 1 G or 1.5 Gs heavier. You wouldn't be too shocked,
though you might feel heavy enough to sign up for Jenny Craig. You
could stand up and walk around - you wouldn't need to crawl. 2 or 3 Gs
is tough, but this is just a little bit stronger gravity than the
Earth. That's a good thing because it means there's less chance of the
atmosphere escaping. You need atmosphere so that water can have enough
pressure to stay in liquid state. On Mars, for example, the atmosphere
is so thin that water can't remain liquid.

What about the weather on this planet? It's tidally locked, which
means one side always faces the sun and one side is always in
darkness. Wouldn't there be incredibly strong winds moving from the
hot side to the cold side?

People thought there'd be hellacious winds. But people have done 3D
climate models of tidally locked planets and their calculations show
there would be high altitude winds like jet streams on our planet. But
according to these models, the maximum winds on the surface would be
30-40 miles per hour on the hot side. On the dark side, winds would be
0-10 miles per hour. It would be quite pleasant. The winds would carry
heat from the hot side to the cold side in the high altitudes and then
the cold winds would come back down over the poles. The winds would
circulate on a large scale like on Earth and that would even out the
temperature somewhat. Some of that depends on whether it's covered by
oceans or continents.

Given the planet's temperature, where would be a good spot to put a colony?

The terminator is the line between light and dark and that would be
where it's most comfortable. Along the terminator you'd want to be
down near the equator because the poles would be pretty cold. So you'd
look to the intermediate to low latitudes near the equator. The sun
would sit constantly on horizon. You could tune your temperature by
moving towards the day or the dark until you were comfy. The
temperatures there might be anything between 160 F to -20. There would
be lots of regions around the terminator that have different
temperatures. We'd pick an equatorial area that's warmer like Mexico
or Equador. You'd be able to stand outside in your shirtsleeves. It
might be tropical. And if you wanted a different temperature, you'd
move your longitude.