[Tolouse]

2 questions:

1. what if the Earth's semimajor axis distance from the sun was .99 times it present distance, how would that affect life on this planet?








2. opposite of the first one: what if the Earth's semimajor axis distance from the sun was 1.01 times it present distance, how would it affect life on this planet?

[CraigD]

Originally Posted by Tolouse

1. what if the Earth was 1 degree closer to the sun than what it is now, how would that affect life on this planet?

2. opposite of the first one: what if the Earth was 1 degree further from the sun that what it is now, how would it affect life on this planet?

The units in these questions don’t make sense.

Degrees are angular, not distance units. Tolouse, can you edit the questions to use units of distance? For example, “what if the Earth’s perihelion (least), aphelion (greatest), or semimajor axis (roughtly, average) distance from the sun was .99 times or 1.01 times its present distance?”

[Tolouse]

thanks, it's been a while since i've had think like that

[Jay-qu]

I would say not a whole lot of difference, since the orbit of the Earth varies more than that much already. ie between perihelion and aphelion.

[nutronjon]

Tolouse's question appears to have not gone far, but what if we ask, "What if the earth had no moon?" How would that change things?

[Tolouse]

oh wow

well, there wouldn't be any pull on the oceans

but other than that, probably a whole myriad of changes

[Moontanman]

Originally Posted by nutronjon

Tolouse's question appears to have not gone far, but what if we ask, "What if the earth had no moon?" How would that change things?

Lots of things would be different my friend, axial tilt would vary as much as 90 degrees or more over time, very little if any land, much more atmosphere, possibly no magnetosphere, slower rotation, faster rotation?, if the earth was tilted 90 degrees on it's axis the polar caps would be spread around the globe at the equator. Probably other things I have forgotten.

[Jay-qu]

The moon has served as a decent gravity well for incoming asteroids that come to close - sucking some of them in and protecting the Earth. The moon as you know provides the tides which work as a very effective mixing spoon, eroding minerals and other important things to life into the oceans. This may have sped up the rate at which life evolved on Earth.