The only KNOWN habitable planet is earth, there is a major difference between the “only” absolute and limits of knowledge.<quoted text> Ego( pride). The only habitable planet, is planet earth.
New solar systems are now being discovered at the rate of two or three a week. It seems that of those stars investigated about 1/3 hold planetary systems However only a relatively few of those discovered planets are suitable for habitation, depending on various factors. The planets chemical make up, its position from is primary and the type of primary and of course the systems position in the milky way.
Note that because of the current limits of technology we can only search relatively close systems in our galaxy, however this of course means that we are searching our little bit of the habitable zone of our galaxy. Our galaxy contains about 300 billion stars and we have as yet only investigated a tiny, minuscule fraction of a fraction of a percent. Then of course there are hundreds of billions of galaxies, most with considerably more stars than the milky way
To say “The only habitable planet, is planet earth.” Is short sighted to say the least. If earth actually is the only life baring planet in the universe I have only one thing to say – such a waste of space…
Here is a list of possibly habitable planets found so far