So far as we are aware, intelligent or otherwise, one. The earth.
However, it is likely that some form of life exists on potentially billions of planets in the universe, and odds are that some of them have developed intelligent life.
Billions of planets are out there. A tiny fraction may be similar enough to Earth to have generated life. A tiny, tiny, tiny, tiny number of those Earth-like planets that have generated life (one-celled creatures) MIGHT have life that has evolved up into walking, swimming or flying animals. A tiny, tiny, tiny, tiny number of THOSE planets may have life that has evolved into something that is is able to use tools, say, a sign of intelligence. (Higher intelligence comes from the 'accident' of the first pre-human to have opposable thumbs . . . that is, thumbs that can touch their fingerprints to the fineger prints of the other fingers.)
The number of planets that would have intelligent life similar to ours is infinitely small.
So . . . consider that 'life' may have evolved on other planets that are NOT based on carbon and oxygen. Perhaps there are creatures, for instance, that breath Methane, and are made of silicon. (Wild example, but . . . . )
At the moment, we still do not know if there is life on any of the other planets in our own Solar system! Mars could have some micro-life forms, and also some of the moons of Jupiter. Jupiter and the other gas giant planets in our Solar system could have created life in their hugely varied atmospheres, but if so, they would likely be nearly unrecognisable to Earth humans.
I'd argue 0, but technically it's 1 if you want to count earth and humans as being intelligent. so there is 2 planets with life on mars
So far, just one. They have found water on Mars which suggests that it's possible for life to exist there. But so far, no one else here but us.
Only the Earth has confirmed to have life on it. It is unlikly that there is life on any other planet.
Earth is the only planet known so far to contain life.
All of the planets in this solar system contain all of those elements, and it is quite likely that every planet throughout the galaxy is likely to contain all of these elements.
All of the other planets may contain some aluminium, though only the four rocky inner planets may contain significant amounts.
Space astronauts went to the planets to be sure there is no life on planets
The Outter Planets
What is the reason that life is less likely on the outermost planets compared to the innermost planets
All planets in the solar system, besides earth, are airless. These planets are not able to contain human life.
All of the planets in this solar system contain all of those elements, and it is quite likely that every planet throughout the galaxy is likely to contain all of these elements.
2
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.
None. Galaxies on the other hand do contain planets
All of the other planets may contain some aluminium, though only the four rocky inner planets may contain significant amounts.
No extraterrestial life has yet been found. While many theories, based on sound statistics, do predict life on other planets, non has yet been proven to exist.Space is vast and huge may take many life times to travel to another solar system where life may contain. There's a small chance if there is life even in that solar system. Also who knows how long ago time started. There could have been life there 10000 years ago or even 1 million years ago. Planets that prove life on other planets could have exploded which will eventually happen to earth. The chances of us meeting life on other planets is very small.
Many planets are devoid of life.
Some do some don't, Earth does but not many have air or water to have life on them.
none that we officially know of but a ton of em actually
So far, earth is the only planet known to support life, but many scientists thing that life probably exists on other planets.
As far as we know, Earth is the only planet that supports life, but there have been many studies that show that some other planets have either supported life previously or could be capable of supporting life.