On Mon, Oct 17, 2016 at 1:21 AM, Bruce Johnson <xxxxxx@pharmacy.arizona.edu> wrote:

You’ll have to play around with temps and this is based on a 1G planet but they have a mars calculator as well; but Canyon wasn’t as cold as mars, IIRC.

I couldn't help doodling with their calculator.

I discovered that a low sea level temp helps *tremendously.* Assuming a "sea level" atmospheric pressure of 0.01 and a desired atmospheric pressure of 0.90 atmospheres . . .

A temp of 0 C requires 146,000 meters (`91 miles) deep.

A temp of -60 C [roughly Mars conditions] requires 112,000 meters (~69 miles) deep.

A temp of -100 C requires 92,500 meters (~57.5 miles) deep.

A temp of -150 C requires 65,700 meters (~41 miles) deep [a distance *deep* equal to the distance from my house to the nearest large town].

(And - yeah - I know I'm using miles. But I can *feel* miles.)

Richard Aiken

"Never insult anyone by accident." Robert A. Heinlein

"I studied the Koran a great deal. I came away from that study with the conviction there have been few religions in the world as deadly to men as Muhammed." Alexis de Tocqueville (1843)

"We know a little about a lot of things; just enough to make us dangerous." Dean Winchester

"It has been my experience that a gun doesn't care who pulls its trigger." Newton Knight (as portrayed by Matthew McConaughey), to a scoffing Confederate tax collector facing the weapons held by Knight's young children and wife.