Science Geeks: If the Earth weren't on a tilted axis, would life still exist?

[Taverner]

If that meteor didn't smack Luna and Terra around so much a billion or so years ago (causing Terra to tilt its axis), would we still have life?

[HiFructosePronSyrup]

1. I don't see any reason why not.

It wouldn't be the same, but given that life started over 3 billion years ago, I don't think a bolide a billion years ago would have stopped it. Unless it had a time machine.

[Taverner]

3. But I heard on a Nat Geo special that if Earth had a "normal" axis, rays would bombard the planet

Causing liquid Water to not exist

[HiFructosePronSyrup]

4. You mean the tilt, or the magnetic field?

Or are you saying the tilt induces the magnetic field.

[Taverner]

5. Not sure - they seem to have implied that one chages, so does the other...

[MrScorpio]

2. Probably not as we know it

So many variables

[MilesColtrane]

6. We would have life...

and we would have Terry Jacks.

But, there would have been no "Seasons in the Sun".

http://www.youtube.com/watch?v=pfm-17pu6SQ

[Orsino]

7. Yep. No seasons.

But be especially glad of that there moon, without which our axial tilt would be all over the damned place. Life would still exist, but couldn't have evolved nearly so far under the resulting climactic swings.

Have you thanked your natural satellite today?

[HiFructosePronSyrup]

8. How would that work?

What does the tile of the axis have to do with the orbit of the moon?

Also, you seem under the common misconception that evolution has a direction or purpose.

[mainegreen]

9. Think he means that the moon moderates the earth's axis precession .

[Taverner]

10. He wasn't saying that Evolution had a purpose

Just that it worked out very very VERY well for us

[Orsino]

11. Very well, thank goodness.

http://query.nytimes.com/gst/fullpage.html?res=9F0CE4DD163CF931A35750C0A965958260&sec=&spon=&partner=permalink&exprod=permalink

The computer simulations by Dr. Wisdom and his graduate student, Jihad Touma, show that under the influence of perturbations over the last 100 million years the tilt of the Martian spin axis has probably fluctuated from 10 degrees to 50 degrees away from a line perpendicular to the plane of the planet's orbit....

Currently, the Martian obliquity is about 25 degrees, an angle not much greater than Earth's, which is 23.5. Earth's obliquity never varies by more than plus or minus 1.3 degrees....

Early this century, the Yugoslav astronomer Milutin Milankovitch demonstrated mathematically that these and other variations, however slight, could have dire climatic consequences, presumably accounting for a succession of ice ages in the recent geological past.

It could be worse. In their computer studies, Dr. Laskar and his colleagues found that without the Moon, the obliquity of Earth might have undergone chaotic variations of up to 85 degrees....

It's an old article (1993), the next line of which refers to the "capture" of the Moon by the Earth. :D

I implied no direction or purpose to evolution, by the way. It's simply reasonable to believe that it would have taken a very different course had the Earth's climate been doomed to much greater fluctuations. I have my doubts as to raw intelligence being able to evolve as far as it has, and civilization would have had a much harder time, too.

[Orrex]

12. It would be almost the same as it is now, except...

Bush would be fighting a war against "the perfectly upright line of evil" instead.