There is no generally-accepted evidence that this occurred. The "alien visitors" theories concerning UFOs and alleged abductions are scientifically unsubstantiated. It is possible that non-intelligent lifeforms may have reached Earth in the form of organic material thrown into space by collisions of other planets or stars.
Earth was possibly visited by people from another Earthy planet or it wasn't visited by at all, nobody it 100% sure if Earth was really "visited". It probably was though.
can someone please tell me!!!!!!!! =(
Scientists say that life can be expected to have evolved on other planets, wherever the environment is not so hostile that life can not be supported. They say that in this vast universe there must be many such planets that can support life and that some are likely to support intelligent life forms even more advanced than humans. Whether we believe that our God created the life on other planets is a matter of human faith. No doubt any intelligent life on other planets will never have heard of Earth's gods.
earth is the only planet known to house liquid water and life
It is important in case there is life beyond Earth.
The biggest reason is water. Astronomers think maybe there really may be traces of water or ice on other planets, but Earth has an abundance, perfect for us. Also, many other planet's living conditions are not suitable. Some planets have EXTREMELY hot hot hot or coooollllddd ccccoollllddd weather that we could not live through. There is not fertile soil or animals to eat (we probably wouldn't be eating aliens :P ). And atmospheres aren't as nice, no substantial protection from the sun's rays and gravity not as strong. There are also some more detailed answers but these are mostly the main ideas why the Earth support life when other planets cant.
Because (as far as we currently know) Earth is the only planet in our solar system that supports life.
Earth's scientist have not found life on other planets to date.
life
Yes, only on the Earth. We don't know if the other planets have life
Astronomers have found Earth-sized planets in other solar systems.
There is life on other planets. Imagine, there are 1000 planets in the Universe for every grain of sand on the earth. That's how many planets there are, so scientifically, the chance that there must be life on other planets as well is much greater than the chance that there is no life.
Other planets do not have water nor life
Fortunately for the other planets, Earth is the only one.
life and water
Because Earth is the only place where we can murder the English language and ask questions like, "Why life is possible only in earth not in other planets?"
Because they are like other life planets they might be able to produce more life when Earth explodes.
earth has air , water and life.
We human beings originated on the planet Earth and so far we have briefly visited the moon but have not established any permanent residence there, nor have we even visited any of the other planets (not in person, we have sent robotic probes).