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Science

jeff47

(26,549 posts)

8. Depends on what's in the atmosphere.

Reply to MillennialDem (Reply #2)

Tue Jan 6, 2015, 04:56 PM

Jan 2015

For example, if Venus had Earth's atmosphere, it would be a bit warmer but easily habitable by Earth lifeforms.

We don't have any idea what the planet's atmosphere is like. It might not even have one. Mars appears to have lost almost all of its atmosphere when its core solidified, so that it no longer had a magnetic field.

We also have no idea what the planet's mass is. It's slightly larger in diameter than Earth, but planets don't have a fixed density. So it could actually have less gravity than Earth....or it could have way more.

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Most Earth-like planet ever discovered could be a cosy home for alien life [View all] n2doc Jan 2015 OP

Very cool! Feral Child Jan 2015 #1

If it's larger than Earth and receiving more heat, isn't it likely to be a runaway greenhouse planet MillennialDem Jan 2015 #2

Depends on what's in the atmosphere. jeff47 Jan 2015 #8

"planets don't have a fixed density" Spitfire of ATJ Jan 2015 #10

Unless the planet is largely crustal with a small nickel-iron core MillennialDem Jan 2015 #11

Not with the information we have. jeff47 Jan 2015 #15

Depends on the greenhouse gas levels. Spitfire of ATJ Jan 2015 #9

Well yes but provided there is significant water vapor / methane / CO2 wouldn't MillennialDem Jan 2015 #12

There were theories that early earth should have done the "runaway" thing too... Spitfire of ATJ Jan 2015 #16

You're presuming the planet has Earth's chemical makeup. jeff47 Jan 2015 #17

Not according to Sen. Inhofe. All that greenhouse stuff is just Al Gore pranking us. tclambert Jan 2015 #13

Cool! Now we just have to travel at the speed of light for 470 years and we can start ruining it! Scuba Jan 2015 #3

I'm positive it wouldn't take us that long. I saw it done on TV once. BlueJazz Jan 2015 #5

... Fearless Jan 2015 #18

LOL! AllyCat Jan 2015 #21

Welcome Keplarians! BrotherIvan Jan 2015 #4

I remember when they claimed dwarf stars had no planets. Spitfire of ATJ Jan 2015 #6

many trillions of miles away heaven05 Jan 2015 #7

Eight new planets where life could exist found Judi Lynn Jan 2015 #14

I wonder what we would be able to find if..... BobbyBoring Jan 2015 #19

You know, maybe this is how everyone in the Old Testament lived AllyCat Jan 2015 #20