Life coming to Earth from space ?

[Cath]

Life could have started and fully evolved here on Earth, life could have arrived here by other means (comet, rocks etc), life I'm sure is very robust when it needs to be, it can adapted to all kinds of conditions, it's also incredibly determined to survive any way it can.

What ever method life used to make it's way here on planet Earth does not preclude any other method that could have been the case. Does it really matter what method it used?

The great mystery is not whether life started here, or life arrived here from else where, the great mystery is that it actually exists in the first place, no matter what method it used to find Earth.

The universe itself is developing life, all life on Earth is living proof of that. The universe is becoming self aware in what ever form it can, we are living proof of that. To assume Earth is the only place in the entire universe where life exists is as far from science as you could possibly get - a conclusion easily arrived at if you take time out to really think about it.

[Mr Spock]

If life particles arrives on Earth from elsewhere then we should have found the same particles on Mars. Until we do there isn't any evidence to support this theory.

[Liquid360]

What I meant by "big picture" was that there could be something, literal communication, at the molecular level, which drives biology forward. Too overreaching and over simplified? Of course! This is an Internet forum filled with laypeople. Doesn't mean we can't propose ideas without evidence. We're just talking, not publishing papers.

- Nate

Birmingham, AL

[LukeSkywatcher]

If life particles arrives on Earth from elsewhere then we should have found the same particles on Mars. Until we do there isn't any evidence to support this theory.

I do tend to agree with this. However, we have barely scratched the surface of Mars so there is still a long way to go to either proving or disproving this theory..............so yes,for the moment we cant count it as fact.

We know the make-up of comets and asteroids and its far more likely that the elements to start/create life came from those as they collided with Earth all those yrs ago. For the same elements to have come from Mars, it would have taken a collision on Mars with a similar type object to send anything from there towards Earth and thats where cross contamination comes into play. We really cant say if life came from Mars alone or from the object that may have collided with Mars and debris from that object arrived here.

Make sense?

I think if we ever find any other life within our solar system that it will consist of what we call extremophiles. They exist here on earth in solid rock, boiling water,very low oxygen environments etc etc.

[Pig]

Life must have come from space whichever way you look at it because Earth is in space  

[Watchman]

Life seems to be very easy, the extreme places it happens on Earth are proof that what we originally thought were totally necessary for life to happen are in fact just a single way it can happen out of many variable possibilities.

I am waiting for evidence that life does not need liquid water, it simply needs liquid something for the other ingredients to use as a medium, such as liquid methane and so on.

[m sutton]

If life particles arrives on Earth from elsewhere then we should have found the same particles on Mars.

Why?

(I'm not being confrontational, just wondering)

[tenbyfifty]

hmmm... where did life on Earh originate:

somewhere with lots of liquid water,

somewhere with a constant supply of heat and light from a nearby stable star,

somewhere with just the right amount of gravity,

somewhere with lots carbon, hydrogen,nitrogen,oxygen, phosphorous and sulphur,

somewhere with lots of other useful elements spewing out of volcanoes,

somewhere with lots of electrical storms which may act to catalyse simple molecules

into more complex ones 

plus lots of other stuff that someone more expert than me could mention.

where could that be? 

oh I know, outer space - yes that's it, life came from outer space !!

Surely not Earth? that irrelevant little planet that's cradled and nurtured life for 3.5 billion years,

no, no that's far too obvious - let's go for the science fiction explanation

and ignore the herd of elephants in the room shall we?

[stevepeverall]

Regarding the original publication:

“Most people will assume that these biological particles must have just drifted up to the stratosphere from Earth, but it is generally accepted that a particle of the size found cannot be lifted from Earth to heights of, for example, 27km. The only known exception is by a violent volcanic eruption, none of which occurred within three years of the sampling trip.

“In the absence of a mechanism by which large particles like these can be transported to the stratosphere we can only conclude that the biological entities originated from space. Our conclusion then is that life is continually arriving to Earth from space, life is not restricted to this planet and it almost certainly did not originate here.”

More holes than a Swiss Cheese.

My initial take on it was that the research grant had run out and they were publishing what few results they had in order to whet appetites in a bid to attract future funding.