Spreading life throughout the universe

This is the "South Pillar" region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope "busted open" this murky cloud to reveal star embryos tucked inside finger-like pillars of thick dust. Credit: NASA

Panspermia hypothesis proposes that life travels between stars and planets, surviving the effects of interstellar journeys and finally settling down on a planetary surface, beginning new evolutionary processes. The microorganisms can be transported to random destinations by asteroids, comets or meteoroids or distributed intentionally by some intelligent alien civilization. But with Earth as the only example of a life-bearing planet, the essential question is: If panspermia really occurs, how could we detect it?

"It is possible for life to be carried by rocks which are ejected from one planet, after an impact by an asteroid, and land on another planet. This can happen by chance if the two planets are in the same planetary system or, with smaller likelihood, if they are in different systems. Although this process is possible, we have no evidence for it," said Abraham Loeb, chair of the Department of Astronomy at the Harvard University, in an interview with Phys.org.

Loeb is the co-author of a paper published in Astrophysical Journal Letters suggesting that if life spreads via panspermia, it does it in a characteristic pattern that we could identify.

His research shows that this pattern would be similar to the outbreak of an epidemic. Loeb compares spreading microbial organisms to an infection with pockets of life. He states that there is a biological similarity between panspermia and disease spread: Any species that evolves panspermia abilities would have enormous fitness advantages. Just as viruses evolved to brave the harsh environment of "inter-host" space to harness the energy of multiple biological hosts, perhaps evolution has or will drive a class of organisms to brave the harsh environment of interstellar space to harness the energy of multiple stellar hosts.

The panspermia theory and the model introduced by Loeb and his colleagues may be the keystone in the search for extraterrestrial life for future generations. Moreover, Loeb believes that we will soon find traces of alien microorganisms.

"In my view, it is likely we will detect evidence for primitive life within the coming decade or two. This first fingerprints of life will probably be identified in the atmospheres of extra-solar planets through spectrographs on the next generation of telescopes," Loeb said.

Researchers look forward to such future instruments as NASA's Transiting Exoplanet Survey Satellite (TESS), which would come in handy when searching for signs of extraterrestrial life. TESS, a space telescope to be launched in August 2017, is designed to be capable of detecting hundreds of Earth-like exoplanets. Ground-based and space-based follow-up observations characterizing exoplanet atmospheres could look for biosignatures such as oxygen in combination with a reducing gas.

But according to Loeb, it is likely that only a few Earth-like exoplanets will be close enough to be biologically characterized with new instruments in the future. Eventually, surveys could test for more specific spectral signatures such as the "red edge" of chlorophyll or even industrial pollution. It is also possible that searches for extraterrestrial intelligence in the radio or optical wavelengths could yield signals that could be tested for clustering.

"Intelligent life can spread intentionally with a higher probability. We have no evidence for that, either. The lack of evidence for the spread of alien civilizations despite the large number of stars in our galaxy is known as the Fermi Paradox," Loeb noted.

The famous question, "Where is everybody?" remains unanswered, even though we are developing more tools enabling increasingly detailed searches for alien life forms. With Loeb's words in mind, it may be that if we are successful in finding , it is highly probable that the seeds of sent intentionally by an advanced intelligent civilization will be found first.

Explore further

Interstellar seeds could create oases of life

More information: Statistical Signatures of Panspermia in Exoplanet Surveys, arXiv:1507.05614 [astro-ph.EP] arxiv.org/abs/1507.05614

A fundamental astrobiological question is whether life can be transported between extrasolar systems. We propose a new strategy to answer this question based on the principle that life which arose via spreading will exhibit more clustering than life which arose spontaneously. We develop simple statistical models of panspermia to illustrate observable consequences of these excess correlations. Future searches for biosignatures in the atmospheres of exoplanets could test these predictions: a smoking gun signature of panspermia would be the detection of large regions in the Milky Way where life saturates its environment interspersed with voids where life is very uncommon. In a favorable scenario, detection of as few as ∼25 biologically active exoplanets could yield a 5σ detection of panspermia. Detectability of position-space correlations is possible unless the timescale for life to become observable once seeded is longer than the timescale for stars to redistribute in the Milky Way.

Journal information: Astrophysical Journal Letters

© 2015 Phys.org

Citation: Spreading life throughout the universe (2015, October 19) retrieved 23 August 2019 from https://phys.org/news/2015-10-life-universe.html
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User comments

Oct 19, 2015
Can't try to breed such organism? First adopt it to temperatures, radiation and hibernation and then try to go vacuum. It would be probably good to start with something already sturdy like OU-20. Of course these microbes should also do something like terraforming.

Oct 19, 2015
Color blind aliens might not be able to hypothesize the existence of a larger spectrum of EM, and therefore might have trouble discovering radio...

They might not be interested in whether they are alone or not, or exploring other planets. They may have a fatalistic or "who gives a damn" attitude.

Or maybe they've considered the possibility of a radically advanced, militaristic hostile race (such as humans) existing, and they are *hiding* so as not to be found.

Or maybe they all went extinct in their version of WWII.

Or their home star blew up and killed them all billions of years ago.

Or there's signs posted at regular intervals a few light years from Earth saying, "Danger: Irrationally Aggressive Hostile Semi-Intelligent Organism. Make no attempt to contact."

Maybe they wiped themselves out in a genetics experiment, like the founders in the Prometheus movie.

Maybe "Dinosaurs" never got wiped out by a meteor on their would-be planet.

Oct 19, 2015
Maybe we are the ones who will seed the whole universe with life, which I recommend we get started with as soon as possible.

Intelligent Design is true, by the way. We have proven it in the laboratory...we've made Genetically Modified Organisms.

haha. Silly atheists. You proved life can be designed, but you haven't proven it can be an accident.

The evidence supports design.

Oct 19, 2015
This comment has been removed by a moderator.

Oct 19, 2015
One thing for sure. The answers to most of our questions will be found from advances in microscopes and advances in telescopes. These are the number one needs for advancement.

Oct 19, 2015
I think research on panspermia is a reasonable use of resources. This article contains some interesting speculation. But I must register dismay at the unbridled use of anthropomorphism: "Just as viruses evolved to brave the harsh environment of 'inter-host' space... perhaps evolution has or will drive a class of organisms to brave the harsh environment of interstellar space."

I must insist that this sort of pseudo-exposition is nonsense. Evocative nonsense though it may be, it is still decidedly nonsense. I am embarrassed to have to state the obvious here: viruses do not "brave" harsh environments; nor would organisms that ride along on comets somehow develop courage. To imply that life "tries" to survive or evolve or travel is to run head-on into our whole understanding of biology. If evolution required goal-directed participation by organisms, it would become biased, and could probably not function as the superbly effective process with which we are familiar.

Oct 20, 2015
It is likely that Fred Hoyle missed out on one of the most deserved of Swedish prizes due to the supposed embarrassment his promulgation of the panspermia concept caused the scientific community (rather than his archaeopteryx shenanigans). Yet here we are in the 21st century and panspermia is still a serious topic. Go figger.

Oct 20, 2015
haha. Silly atheists. You proved life can be designed, but you haven't proven it can be an accident.

The evidence supports design.

The evidence is overwhelming for common descent. You can hypothesise that the single cell common ancestor was designed but if you invoke the supernatural then you are outside the bounds of Science and off into fairy land.

Oct 20, 2015
Necessity: Vision Development spirit
The Indian Philosophy forms the backbone for Biological minds to catch-up with the Galactic Plane . The Human Being has various frames of Minds
1.Biological Frame leading to 2.Philosophical Frame and superimposition of 3.Divine Frame. several questions arise out of 4.Nature Divine Frame and 5.Cosmic Divine Frame.
Here Super-imposition of visible-invisible matrix modes presented by the author at COSPAR 2013 helps scientific research to catch-up with Space data provided by NASA,ESA,HST many Space probes like SOHO in search of life and extra-terrestrial life. my books are available through lulu- Cosmology Vedas Interlinks- Vidyardhi nanduri {independent Research]

Oct 21, 2015
In some ways we need look no further than our selves to see proof of panspermia. Only species with logical speech. Only species whose females are in heat ALL the time. Only species with OUT a penis bone. Only species with opposable fingers and bipedal. Only species to make real tools. Only species to innovate and pass on knowledge....the list is on and on. WHERE do ;you suppose we got all that?

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