Question of the Week

Life from Outer Space?

Sun, 11th Jan 2009

Listen Now    Download as mp3 from the show New Year, New Naked Science


John Wilson, Netherlands asked:

Have they found any life in the rubbish that falls to Earth from outer space?


We put this to Dr Vic Pearson from the Open University:

Structures on ALH84001 meteoriteThe likelihood of finding life in meteorites is probably pretty slim. There was, in the 1990s, a big debate on whether or not NASA scientists had identified nanobacteria, so very small bacteria only identifiable using very powerful microscopes in meteorites that had come from the surface of Mars. This has pretty much been debunked now. That’s not to say that the building blocks of life may not have been brought in meteorites because meteorites themselves contain biogenic elements such as sulphur, nitrogen, phosphorous. Also, carbon-based molecules or organic molecules which are required for life on Earth and elsewhere in the solar system: these are things such as amino acids, carboxylic acids, sugars – all of which make up living systems on the Earth and all of which are the backbone of the organic molecules that make up our own DNA. The chances of being able to find life elsewhere in the solar system is also a lot stronger by the fact you can find the organic molecules. Whether or not you can actually get life itself from meteorites is probably very unlikely.


Subscribe Free

Related Content


Make a comment


Give me a definition of life:)
What they have found is organic molecules such as sugars and amino acids.
Now scientists think that they've found "complex organic chemicals used to make self-replicating molecules that are genetic ingredient of all known lifeforms – DNA and RNA - inside a meteorite, life originating with the aid of extraterrestrial molecules that might have come from space more than 3.6 billion years ago.'
But I don't know of any 'living' organisms found from outer space.
The times they've though they found such, it most probably has been 'contaminated' from Earth.
Or have they? yor_on, Sat, 27th Dec 2008

Of course not. At least the way we know life is. But we may have certainly come across some organic molecules. Who knows maybe life has been triggered on earth through these fallen debris ?
There was a news that a fossil of a bacteria was found in the rocks fallen from mars.  kancha, Sat, 27th Dec 2008

If they've found any, the secret agencies are not telling. Chemistry4me, Sun, 28th Dec 2008

If they fall on our planet.. And it comes at great speed... It is like a fireball..
So all the organisms would have burnt to death anyway
Just my theory seanahnuk, Tue, 6th Jan 2009

And those life forms that make it to the ground are obviously very hot, as a result jump off the rock, and scatter to find water to cool their jets. No wonder we cannot find any.

Karsten Karsten, Wed, 7th Jan 2009

A valid theory which has been tested. Some resarchers simulated the effects of riding a meteor into the Earth on some bacteria. The vast majority of them were burnt up, but a very small percentage survived. Which is all you need. The inside of a meteor doesn't always get that hot when entering the Earth's atmosphere. Bacteria can be pretty hardy, some have been found growing inside nuclear reactors.

Dr Pearson is talking about a hypothesis called psuedopanspermia, which is that as she say some of the building blocks of life may have come from meteorites and comets. The more controversial panspermia hypothesis is that life (bacterial) itself fell from space. Few researchers in the area hold to the theory (and the ones that do tend to be a little strange), but I see little reason to rule it out.

I met some people from the SETI institute at an origin of life conference once and they assured me that if they or NASA had evidence of life from space they would be the last people wanting to keep it secret. It would mean a massive boost to their funding. But would other government/military agencies try to stop them? bryan, Wed, 14th Jan 2009

I suppose it would depend on what they find
Chemistry4me, Thu, 15th Jan 2009

Where do you think we all came from?...
(cue in sinister laugh)
we didn’t originate in this planet... this is just a Petri dish that is being watched closely –very closely.

Emilio Romero, Thu, 15th Jan 2009

If you insist Emilio Romero ! Chemistry4me, Fri, 16th Jan 2009

Hmmm, That would explain 'the eyeballs in the sky'. Don_1, Fri, 16th Jan 2009

It's not that slim. Matching the elemental makeup of meteorites that landed in the Antarctica a great many years before mankinds appearance on the evolutionary scale had what are called polycyclic aromatic hydrocarbons. This particular hydrocarbon makeup is in fact the perfect ingredients for microbe-like life. Also metreorites can act like life-sustaining capsules over long periods of time, as though preserved in their frozen environment.

So, i disagree. Whilst it being not only probable, it's also possible that the theory of Panspermia is an excellent theoretical description of how the first prokaryote of life appeared from which all eukaryotic lifeforms evolved from. Mr. Scientist, Thu, 12th Nov 2009

My ex wife is clearly from outer space. More then that, I truly believe she was deliberately expelled for reasons I will not elaborate. It might endanger the entire planet. litespeed, Tue, 5th Jan 2010

Very interesting. Thanks for the share.


all inclusive vacations
SamTHorn, Tue, 20th Apr 2010

See the whole discussion | Make a comment

Not working please enable javascript
Powered by UKfast
Genetics Society