Good question! I think a strong magnetic field is a must, I also wonder about having a decent size satellite, such as our moon.

That's an interesting observation. I, too, have often been struck by how many quirks of our planet seem to have contributed to life forming here.from the Goldilocks Zone, to iron cores and magnetic fields, to the tilt of our axis in relation to our orbit around the Sun.

All, and more, seem to have been the spoon that stirred the primordial soup to produce life. That or acted as shielding that kept mutation at sustainable levels for evolution.

I think the instances of life - as we would recognize it - in the Universe are more rare than most of us might think.