Life on other planets?

Question

For science I have to predict and stuff wether there could be life on other planets. I am personaly thinking yes, because of religous reasons, but thats not valid as this is a school report. does anyone have any logical, scientific reasons why there could OR COULD NOT be life on another planet than Earth?

Answer 1

If you mean as in the universe. Well yes there has got to be. The universe is so vast and earth coudn't possibly be the only planet with life. Plus water and bacteiria have been detected on mars before. Now humans have also found out that red dwarfs stars can also hold planets in orbit that can contain life. I would definitley say yes. But why,well there is no way quite yet to prove it but all of the above points can be added.

Another thing is that if you take a look on earth, in regions where you believe life may not exist, you will find bacteria called Extreamophiles. And based on that scientists believe that life is hidden under the gases of jupiter and the frozen methen seas of its moon europa and saturn's moon titan.

I suggest the book Faint Echoes, Distant Stars (by DR.Ben Bova). It has a lot of info on the topic.

Answer 2

There is no reason why life cannot exist on another planet, but to work out an estimate of how likely there is of life existing you have to use probability and some GUESS WORK.

Something like this:

There are 100 Billion stars in the Milky Way (There are actually between 200 - 400 Billion but that doesn't matter)

There are about 100 Billion Galaxies in the Universe, lets assume they are all similar to ours, that makes:

100,000,000,000 times 100,000,000,000 stars in the universe ! WOW !!!

Now "Life" could mean simply bacteria, but lets assume you need a planet with water on it... so

We know that other stars have planets, we have discovered this, lets say only 1 in 10 stars have planets (It's more likely to be more than this)

And lets say that there is a 1 in 100 chance that a star that does have planets has one the right distance from it to be the right temperature to support life (1 in 1000 overall so far)

Lets say the chance of life occuring on a planet with water at the right temperature is one in a billion... (So we are at 1 in 1000 billion chance now but don't forget how many stars are in the universe)...

100 Billion x 100 Billion / 1000 Billion

I can only do this in standard form in my head so excuse the next line if you are unfamiliar...

10^11 * 10^11 / 10^12 = 10^10

There should be 10 Billion stars with at least Bacteria living on a planet around them !

Answer 3

Personally, I am certain that wherever there is liquid water, we will find microbial life of some sort. If you are asking about sentient life, that's another question.

So far we've seen no verifiable evidence of other sentient species. That said, I believe with some certainty that somewhere in our galaxy at some past, present, or future time, a sentient species did/does/will exist.

Why haven't we heard from them?

Perhaps they are not technologically advanced enough to be heard. They may be mastering stone knives right now, or experiencing their own Rennaisance.

Perhaps they are here right now. Any species sufficiently advanced to travel interstellar distances would be able to hide or masquerade with ease. That Boeing 737 that just flew by may be a surveillance craft.

Perhaps they are so far away they will never notice us and vice versa.

Perhaps they existed a million years ago and died out.

Perhaps they will exist a million years from now.

It is really impossible to know for sure.

The Drake Equation suggests that there is sentient life out there. The Fermi Paradox casts doubt. Play around with the calculation form at the second link and see what you think.

Answer 4

The term "life" is rather broad in its total meaning, and i am not sure you realize that fact. Life encompasses all manner of minute bacteria all the way up to the most complex life forms such as insects, birds, fishes, reptiles, and mammals. Those are the life forms we are rather well acquainted with. It is not a definition of the limits of life, however. On a distant planet life could have a different form altogether.

As to the chances of there being life somewhere else, those odds are pretty good that there is at least one place in the Universe which has life on it. It works like this...

We live on a planet (Earth) which is one of nine planets orbiting a single star (the Sun). Our Sun and nine planets with their associated moons (and meteors and asteroids) form our Solar System. Our star (the Sun) is one of more than 200 Billion stars which make up the Milky Way Galaxy. Now, each one of those 200 Billion + stars could have from 0 to 10 (or more) planets orbiting around it along with their associated moons.

And, beyond the Milky Way Galaxy there are 100,000 plus other galaxies which contain billions of stars in each one of them. Yes, you guessed it... Each one of those stars could have from 0 to 10 (or more) planets with their associated moons revolving around them.

So, with such a vast number of possibile planets out there, it is rather simple to suggest that one or more might have all of the right features to be an Earth Equivalent.

That does not in any way imply, however, that life developed on that planet in lock-step, timewise, with the development of life here on Earth. Life on that distant planet might have been slower to develop, or much faster to develop that on Earth. It is also entirely possible that life developed on this equivalent planet and was wiped out entirely long ago by a collision with a monster asteroid, or the onset of some widespread disease, or some other natural catastrophe.

Finally, it is important to recognize that life forms here on Earth developed because of a string of particular events which may not have been replicated exactly on the distant Earth equivalent planet. Certain events, indeed, caused specific life forms to fall into extinction and disappear .forever. Some species could not cope with specific climate changes on Earth, for example. As a result,
it is not satisfactory to presume that life forms develop the same way everywhere, or over the same time span everywhere. And, when we discover life somewhere else, it might be in the form of super intelligent fishes and reptiles, or utterly fantastic birds, etc., etc. It is not worthwhile to assume that these intelligent fish or birds have Channel 3, 5, and 9 Television, their version of the Dallas Cowboys, Windows XP Software, XM Radio, or a Miss Universe Contest like we do. Logic which says that it is a mirror image of ours is not possible to support in any way.

Answer 5

The universe is immense and seems to be growing. There are billions of suns and galaxies. (I rounded off because I lost count and didn't want to start over) LOL
The only real proof, at the moment, that there is life on other planets are statistical analysis. The probability of life on other planets cannot be zero because there is life on our planet. If it is possible for life on earth there has to be life elsewhere. What type of life is there we don't, but it is out there. To prove that there isn't life can't be easily done because it is difficult to prove a negative.

Answer 6

The Universe is full of all of the ingredients necessary to create and sustain life. As Earth proves, under the right environmental conditions, life “can” exist. Whether similar life favorable environments exist else ware is the question.

Answer 7

There are billions of stars, galxies and planets in our Universe. The prospect of life on other planets is significant with such a vast array of cosmic life, there has to terrestrial life.

Answer 8

If you are talking check out Jupiter's moon Europa, but if you mean everywhere in the universe, in my opinion there is a 99.99999999999% chance there is life out there. Also wouldn't religion be a reason for why life is only on earth...

Answer 9

Yes,it is 99% possible that there is life on other planets.

1.There are thousands, or maybe millions of galaxies around the universe
2.Our planet Earth belongs to just one galaxy.
3.We are just merely a very small part of our galaxy,''take this for example,,,''the beach is our galaxy,,then earth is just a grain of sand in that beach(comparison only but true)

just imagine, if we (earth) is just a very tiny part of just merely one galaxy,just imagine how many millions of planets are still undiscovered in our galaxy alone,not to mention that there are still millions of galaxies around the universe.


I apologize for my explanation for it is not ''clear'' as i say.
but,,i do hope you get it.
Cheers!