Across the universe,is human alone?Is there any living things out of space?
As we all know,there are nine stars in the solar system:Mercury、 Venus、 Earth、Mars、Jupiter、Saturn、Uranus、Neptune、Pluto.Except for the Mars,the other stars' condition is so extreme.On these stars,there is no air,no water.And it is so hot in daylight,and so cold in at night.So,there is no life on these stars.Only the Mars is under almost the same condition with the Earth.Besides the likely time they spend on turning a round,they have almost the same air,consisting carbon and oxygen,which is the necessary condition of live.
Out of solar system,millions of stars shines in the sky.Imagine!There must be some stars like the Sun,and others like the Earth and the Mars.On the same condition,living things are possible.
In a word,considering the condition of the Mars and stars out of the solar system,there must be other living things in the universe.