[MMaschin]

Yep. Just check out the estimated 100,000,000,000,000,000 stars so far discovered in the universe and you will see that there cannot be any other planet anywhere like Earth because there just aren’t enough stars in the universe ... /s

Of course, the Earth-Moon collision, as well a the origin of Earth’s core, are all theories and you know what happens to theories in time, right?


I didn't say there were no other Earth-like planets, I said they they are much rarer than people are led to believe.

How many planet sized objects develop in a solar system? And what are the odds that 2 would collide, and leave an Earth like planet? If we say it is 1/Billion (I believe it's far less likely), that means there would be a grand total of 250 in the Milky Way.

My point was that the media proclaims 'Earth-like' planets are common, that could not be further from the truth. Add the requirement for an Earth like moon to the Drake equation, and it completely changes the outcome.

[PIF]

Just how do you know all those assumptions of yours are correct when no astronomer knows? There could be many ways a planet could form without collisions and still have a nickle-iron core. Who said Drake was correct? They are just theories which are constantly evolving or otherwise changing, there are no absolutes, just guesses.

20 years ago you would have been laughed at to suggest in two decades hundreds of solar systems would be found with planets.