“Up until now the oldest stromatolites have been from Western Australia and they are roughly 3,500 million (3.5bn) years [old],” said Clark Friend, an independent researcher and co-author of the research. “What we are doing is pushing the discovery of life earlier in Earth’s history.”The discovery, says Friend, also raises questions about the possibility of life on other planets.“If we have got life at 3,700 million (3.7 bn) years on Earth, did it exist on other planets - because Mars, for example, 3,700 million years ago was wet,” he said.
Dartnell agrees that the discovery could help researchers explore whether life was once present on other planets. “The Martian surface today is very cold and dry, but around the time that these ancient layered rocks formed in Greenland, Mars was itself a much warmer and wetter, and thus habitable planet,” he said. While finding stromatolites with robotic landers or even manned missions is likely to be challenging, says Dartnell, if stromatolites are present, they could offer a wealth of information. “On Mars, we’d expect stromatolites, even as old as 3.5-3.8 billion years, to be better preserved than on Earth as Mars hasn’t experienced geological processes like plate tectonics,” he said.
4.1 billion years ago, there were oceans on Venus as well. Just saying
Makes you wonder if this indicates that as soon as a planet finishes forming, that providing conditions are right life will spring up ASAP. Considering that it's now believed life could have started on Earth 4.1 billion years ago, so very early on.
Quote from: Star One on 09/01/2016 06:37 amMakes you wonder if this indicates that as soon as a planet finishes forming, that providing conditions are right life will spring up ASAP. Considering that it's now believed life could have started on Earth 4.1 billion years ago, so very early on.The flip side of that is, will we find that all local life is/was a close relative? A lot of stuff has been exchanged between the bodies of the Solar System as a result of impacts, and these used to be far larger and more common than nowadays. Now, as for exoplanets...
I'm sure there could be fossils on Mars. This discovery just says it is possible. There is more likely to be fossils on Mars as opposed to living organisms; if anything it is a matter of finding where to look first.
Quote from: redliox on 09/01/2016 10:54 amI'm sure there could be fossils on Mars. This discovery just says it is possible. There is more likely to be fossils on Mars as opposed to living organisms; if anything it is a matter of finding where to look first.The only place I could see life surviving on Mars is in its caves and caverns.
Speaking of which, an upside of Global Warming here may be the deposition of meteorites as glaciers retreat - though, oddly, I've never seen any mention of meteorites in moraines etc - perhaps early Iron Age people grabbed all the irons!
The best place to look for Venus fossils will be anywhere but Venus, where the weather and geology are terrible. Ice caps, glaciers and shadowed points on Earth, the Moon and Mercury can preserve and sort incoming material better than any other locations. Rather than looking for needles in a haystack, you seek fossil-bearing meteorites among those to be found on the 'shores' of ice where it has sublimated away. People do this already on Earth, and it wouldn't be impossible to do this robotically elsewhere.
Quote from: Star One on 09/01/2016 06:37 amMakes you wonder if this indicates that as soon as a planet finishes forming, that providing conditions are right life will spring up ASAP. Considering that it's now believed life could have started on Earth 4.1 billion years ago, so very early on.Well, if you take the age of the fossils, 3.8 Ga, then it's not that fast. Almost the same amount of time between the formation of the planet and the first fossils as between the Cambrian explosion and today... And Earth was apparently habitable (cool, with running water and possibly an ocean) quite early on (=~4.4 Ga).
There was an article recently putting forward the view in a very recent New Scientist that life could have arisen on Earth multiple times.https://www.newscientist.com/article/mg23130870-200-life-evolves-so-easily-that-it-started-not-once-but-many-times/
Quote from: Star One on 09/03/2016 07:07 amThere was an article recently putting forward the view in a very recent New Scientist that life could have arisen on Earth multiple times.https://www.newscientist.com/article/mg23130870-200-life-evolves-so-easily-that-it-started-not-once-but-many-times/Ahh, New Scientist.It's certainly plausible that there were many biogenesis events on Earth, but all evidence (DNA phylogeny) points towards one completely dominating to the extent that those organisms wiped out all the others.One interesting hypothesis involves RNA-based life, which is possible but for which we've really never looked. It is described in Peter Ward's book "Life As We Do Not Know It." We could have a shadow biosphere all around us that our DNA bias has caused us to ignore.
Quote from: jgoldader on 09/03/2016 01:37 pmQuote from: Star One on 09/03/2016 07:07 amThere was an article recently putting forward the view in a very recent New Scientist that life could have arisen on Earth multiple times.https://www.newscientist.com/article/mg23130870-200-life-evolves-so-easily-that-it-started-not-once-but-many-times/Ahh, New Scientist.It's certainly plausible that there were many biogenesis events on Earth, but all evidence (DNA phylogeny) points towards one completely dominating to the extent that those organisms wiped out all the others.One interesting hypothesis involves RNA-based life, which is possible but for which we've really never looked. It is described in Peter Ward's book "Life As We Do Not Know It." We could have a shadow biosphere all around us that our DNA bias has caused us to ignore.RNA life probably preceded DNA life, and was probably ancestral to it.I would have thought the RNA life, if still extant would be visible through ribosomal RNA testing of soils etc. But I will have to read Ward's book, he is a stimulating writer (and speaker for that matter).