Thread: If Mars was closer to the sun

Lets say during formation Earth never existed and mars took its orbit around the sun. Would Mars be habitable? I understand its smaller and less likey to support life but if it formed in Earths orbit maybe conditions would be different.

But wouldn't it then just be the same as Earth but with smaller people?

No, it still would have cooled, lost it;s dynamo, and had it's atmosphere stripped.

Id think it would develope an entirely different species. One that has to adapt to the smaller gravity.

So what if it was denser say instead of 3.93 g/cm3 it was 5.75 g/cm3. Would the core cool as fast with the extra mass of a denser core.

it would still cool as fast, but it would contain more "energy" so the cooling would take longer. I still wonder if mars has some liquid core left, and some magnetic field. If so it could be restarted if we imput enought energy. (theoretically)

How would it cool as fast yet take longer to cool because it has more energy? Look at mercury that planet has a molten core and a magnetic field to go with it. So i would think with the higher desity=higher mass mars would have a decent magnetic field though not as strong as Earths.

I think he meant to say that the rate of cooling would remain constant, but the initial amount of energy in the system would be higher so the time required for Mars to cool would have lengthened. At least, that's how I read it.

Originally Posted by KTevolved

Lets say during formation Earth never existed and mars took its orbit around the sun. Would Mars be habitable? I understand its smaller and less likey to support life but if it formed in Earths orbit maybe conditions would be different.

Life would be different though. Your legs would be much longer and thinner, you would have a larger weight and probably be in a spider like shape in order to grab the ground to run at faster speeds.

Originally Posted by KTevolved

Lets say during formation Earth never existed and mars took its orbit around the sun. Would Mars be habitable? I understand its smaller and less likely to support life but if it formed in Earths orbit maybe conditions would be different.

Conditions would be a lot different.

1. There would not be a large moon to stabilize the Axial spin. Which would cause some major problems with the weather. Also, much smaller tides.
2. The planet would need some way to replenish lost atmosphere. Would need volcanism, liquid water, some way for primitive life to start terraforming the planet.
3. Without a magnetic field the charged particles of the solar wind would be very hard on life.
4. How the lessor gravity would affect life, I have no idea.
5. I think maybe primitive life could have developed, but more complex life is rather doubtful.

Originally Posted by Oxycodone

Originally Posted by KTevolved

Lets say during formation Earth never existed and mars took its orbit around the sun. Would Mars be habitable? I understand its smaller and less likey to support life but if it formed in Earths orbit maybe conditions would be different.

Life would be different though. Your legs would be much longer and thinner, you would have a larger weight and probably be in a spider like shape in order to grab the ground to run at faster speeds.

Well, i doubt that for a large creature it would be viable to have more then 4 appendages, as no large creature has them, apart from a giant octopus. Still these creatures use 60% of their brain capacity just to move..

@Flick, yes thats what i meant. With rate of cooling i mean the loss of energy. I calculate that by looking at the transmission speed per thermal unit, and the actual difference in temperature.

Originally Posted by Oxycodone

Life would be different though. Your legs would be much longer and thinner, you would have a larger weight and probably be in a spider like shape in order to grab the ground to run at faster speeds.

I like the evolutionary speculation game.

I would imagine that on a world with comparatively low gravity and a thin atmosphere, being earth-bound (figuratively speaking) would limit you. I think jumping organisms would stand a better chance as they could take advantage of the reduced atmospheric friction and the limitations of friction and grip on sandy surfaces that would hinder traditional running organisms.

I would almost lean toward flying altogether, but the lack of atmospheric convection might make it more trouble than it's worth.

It is an interesting question and one capable of generating a lot of theories.

I was thinking if its density increased thus its mass then it would have more gravity to hold onto the atmosphere. When this extra thickness it might have held onto liquid H2O. This extra desnity would come from the core and with a bigger denser core it might be liquid. With it being liquid it might have a magnetic field.

Are you talking about a planet with Mar's current dimensions in Earth orbit? Or are you reforming Mars? In which case, you basically have the earth.

Reforming mars upping the density to Earths density and keeping the radius. This new planet mars would be in Earths orbit with a magnetic field. Im wondering if it with more gravity 0.5 G could have an atmosphere that would retain liquid water? Hypothetically speaking.

I would think it would but i need to be sure.