[petuniasevan]

You've got it.

A clear definition of the term "Earth-like" is everything.

"Earth-like" can simply mean "ball of rock and metal" as opposed to the Jupiter-like "ball of swirling gases".

What size range are we looking for? Any moons?

Is an extrasolar planet "Earth-like" if it orbits way too close or far from its parent star to support life? What if it's in an extreme orbit in a binary star system?

Does "Earth-like" presuppose a magnetic field?

And what if the candidate planet had a poisonous atmosphere (or none)?

[Sabertooth]

Would an Earth-like planet require a Sol-like solar system?

Would that Sol-like system course placidly on the galactic periphery, as ours does? Wouldn't that exclude a big chunk of the 400 billion stars in the Milky Way as candidates?

Would there be lots of circular orbits, and friendly gas giants sucking up space debris along the perimeter?

Would an Earth-like planet exist in what is basically a binary planetary system, as is ours with our Moon?