JCandeias wrote:A-L-E-X wrote:Source of the post But is this how it really is? From what we read in science news stories earth-like planets are being found right and left! (and multiple ones in the same solar system!)
"Earth-like" in news stories on exoplanets only means that the planets have near-earth diameters (usually, since the most prolific method of detection is transits and those detect diameters; much more rarely, masses are also known) and theoretical temperatures. Nothing else. The vast majority of those planets should be nothing like the Earth. To illustrate it, an ET watching our Solar System from afar would deem not only the Earth but also Venus and Mars Earth-like (Mars only marginally so). Yet, Mars is a cold lifeless desert and Venus is a superhot lifeless greenhouse of a desert.
Thanks, is that because the vast majority of planets should not be like each other? I'm not in the camp that "Earth is special" until we have a much larger sample size. I think that if we explore enough of our galaxy, we'll probably find 100s of planets like Earth, but we lack the ability to see that far.
Also, a planet need not be earth-like for it to be habited- there are all different kinds of exotic biochemistry possibilities.