Because earth does not need to be alone
There are probably a billion stars in our galaxy, and probably a billion galaxies in the universe. We already know what there are planets orbiting many other stars; if there are planets around only 1% of the stars, that's still 100 billion planets. If only 1% of those planets are habitable, that's a billion habitable planets. If only 1% of those planets HAVE life, that's 10 million planets with life. If only 1% of the planets that have life have highly-developed life forms, then there are 100,000 planets with highly developed life forms. If only 1% of those planets have intelligent life, that's still 1,000 planets in the universe that have intelligent life; "aliens". We have NO IDEA if there are any other planets that have life, or intelligent life in the universe, or if those aliens - if any exist - might be willing or able to communicate with us. But I would like to think so.
Seeing as there are 344 discovered planets, and Earth is the only one with life, there is a 1/344 probability so far. the more planets discovered without life, the less the chances are that there could be life on them
Scientists are still bringing stuff back to earth from other planets to look at but, from the information we have now we say that only 1 planet has life. That planet is Earth.
i did this research and made my own equation on my own, take our Galaxy for example 1 galaxy=150-350 billion stars lets take 250 billion stars, and if each star has a solar system of 1 to 9 planets, lets say each star has 5. 5 planets times 250 billion stars = 1,250 billion planets and if at least 1 in 5 planets has life on it 1/5 X 1,250 billion planets = 250 billion planets so i think maybe at least 250 billion planets in OUR galaxy have life but that's only our Galaxy (Milky Way) and in the universe there are billions of galaxies maybe trillions, and how do we know this is the only universe, could there be more?
That there is none to be proven so far. Theres millions of Galaxies out there, both the moon and Mars were found to have frozen water on them! there would at least be 1 other planet with life. If you agree or disagree post your answer in another paragraph below with your username.
Theres only 1 fantage.
Neptune has only 1 sun, like all planets
Earth
I think theres only 1
theres only 1 and that involved the gouvernment
to the wild unless its a theres only 1 becuss that 1 dies
theres only 1 continent and that's Europe