Category: Phenomena (page 2 of 2)

Messy Chemistry, Evolving Rocks, and the Origin of Life

Ribosomes are life’s oldest and most universal assembly of molecules. Today’s ribosome converts genetic information (RNA) into proteins that carry out various functions in an organism. A growing number of scientists are exploring how earliest components of life such as the ribosome came to be. They’re making surprising progress, but the going remains tough.

 

Noted synthetic life researcher Steven Benner of Foundation for Applied Molecular Evolution (FfAME) is fond of pointing out that gooey tars are the end product of too many experiments in his field.  His widely-held view is that the tars, made out of chemicals known to be important in the origin of life, are nonetheless a dead end to be avoided when trying to work out how life began.

But in the changing world of origins of life research, others are asking whether those messy tars might not be a breeding ground for the origin of life, rather than an obstacle to it.

One of those is chemist and astrobiologist Irena Mamajanov of the Earth-Life Science Institute (ELSI)  in Tokyo.  As she recently explained during an institute symposium, scientists know that tar-like substances were present on early Earth, and that she and her colleagues are now aggressively studying their potential role in the prebiotic chemical transformations that ultimately allowed life to emerge out of non-life.

“We call what we do messy chemistry, and we think it can help shed light on some important processes that make life possible.”

Irena Mamajanov of the Earth-Life Science Institute (ELSI) in Tokyo was the science lead for a just completed symposium on emerging approaches to the origin of life question. (Credit: Nerissa Escanlar)

It stands to reason that the gunky tar played a role, she said, because tars allow some essential processes to occur:  They can concentrate compounds, it can encapsulate them, and they could provide a kind of primitive (messy) scaffolding that could eventually evolve into the essential backbones of a living entity.

“Scientists in the field have tended to think of the origin of life as a process going from simple to more complex, but we think it may have gone from very complex — messy — to more structured.”

Mamajanov is part of an unusual Japanese and international group gathered at (ELSI), a relatively new site on the campus of the Tokyo Institute of Technology. It is dedicated to origin of life and origin of Earth study, with a mandate to be interdisciplinary and to think big and outside the box.… Read more

The Search for Exoplanet Life Goes Broad and Deep

The scientific lessons learned over the centuries about the geological, chemical and later biological dynamics of Earth are beginning to enter the discussion of exoplanets, and especially which might be conducive to life. This is an artist's view of the young Earth under bombardment by asteroids, one of many periods with conditions likely to have parallels in other solar systems. (NASA's Goddard Space Flight Center Conceptual Image Lab)

The scientific lessons learned over the centuries about the geological, chemical and later biological dynamics of Earth are beginning to enter the discussion of exoplanets, and especially which might be conducive to life. This is an artist’s view of the young Earth under bombardment by asteroids, one of many periods with conditions likely to have parallels in other solar systems. (NASA’s Goddard Space Flight Center Conceptual Image Lab)

I had the good fortune several years ago to spend many hours in meetings of the science teams for the Curiosity rover, listening in on discussions about what new results beamed back from Mars might mean about the planet’s formation, it’s early history, how it gained and lost an atmosphere, whether it was a place where live could begin and survive.  (A resounding ‘yes” to that last one.)

At the time, the lead of the science team was a geologist, Caltech’s John Grotzinger, and many people in the room had backgrounds in related fields like geochemistry and mineralogy, as well as climate modelers and specialists in atmospheres.  There were also planetary scientists, astrobiologists and space engineers, of course, but the geosciences loomed large, as they have for all Mars landing missions.

Until very recently, exoplanet research did not have much of that kind interdisciplinary reach, and certainly has not included many scientists who focus on the likes of vulcanism, plate tectonics and the effects of stars on planets.  Exoplanets has been largely the realm of astronomers and astrophysicists, with a sprinkling again of astrobiologists.

But as the field matures, as detecting exoplanets and inferring their orbits and size becomes an essential but by no means the sole focus of researchers, the range of scientific players in the room is starting to broaden.  It’s a process still in its early stages, but exoplanet breakthroughs already achieved, and the many more predicted for the future, are making it essential to bring in some new kinds of expertise.

A meeting reflecting and encouraging this reality was held last week at Arizona State University and brought together several dozen specialists in the geo-sciences with a similar number specializing in astronomy and exoplanet detection.  Sponsored by NASA’s Nexus for Exoplanet Systems Science (NExSS), NASA Astrobiology Institute (NAI) and the National Science Foundation,  it was a conscious effort to bring more scientists expert in the dynamics and evolution of our planet into the field of exoplanet study, while also introducing astronomers to the chemical and geological imperatives of the distant planets they are studying.… Read more

Faint Worlds On the Far Horizon

Faintest distant galaxy ever detected, formed only 400 million years after the Big Bang. NASA, ESA, and L. Infante (Pontificia Universidad Catolica de Chile)

Faintest distant galaxy ever detected, formed only 400 million years after the Big Bang. NASA, ESA, and L. Infante (Pontificia Universidad Catolica de Chile)

For thinking about the enormity of the canvas of potential suns and exoplanets, I find images like this and what they tell us to be an awkward combination of fascinating and daunting.

This is an image that, using the combined capabilities of NASA’s Hubble and Spitzer space telescopes, shows what is being described as the faintest object, and one of very oldest, ever seen in the early universe.  It is a small, low mass, low luminosity and low size proto-galaxy as it existed some 13.4 billion years ago, about 4oo million years after the big bang.

The team has nicknamed the object Tayna, which means “first-born” in Aymara, a language spoken in the Andes and Altiplano regions of South America.

Though Hubble and Spitzer have detected other galaxies that appear to be slightly further away, and thus older, Tayna represents a smaller, fainter class of newly forming galaxies that until now have largely evaded detection. These very dim bodies may offer new insight into the formation and evolution of the first galaxies — the “lighting of the universe” that occurred after several hundred million years of darkness following the big bang and its subsequent explosion of energy.

This is an illustration by Adolf Schaller from the Hubble Gallery (NASA). It is public domain. It shows colliding protogalaxies less than 1 billion years afer the big bang.

This is an illustration by Adolf Schaller from the Hubble Gallery and shows
colliding protogalaxies less than 1 billion years after the big bang. (NASA)

Detecting and trying to understand these earliest galaxies is somewhat like the drive of paleo-anthropologists to find older and older fossil examples of early man. Each older specimen provides insight into the evolutionary process that created us, just as each discovery of an older, or less developed, early galaxy helps tease out some of the hows and whys of the formation of the universe.

Leopoldo Infante, an astronomer at Pontifical Catholic University of Chile, is the lead author of last week’s Astrophysical Journal article on the faintest early galaxy.  He said there is good reason to conclude there were many more of these earliest proto-galaxies than the larger ones at the time, and that they were key in the “reionization” of the universe — the process through which the universe’s early “dark ages” were gradually ended by the formation of more and more luminous stars and galaxies..

But the process of detecting these very early proto-galaxies is only beginning, he said, and will pick up real speed only when the NASA’s James Webb Space Telescope (scheduled to be launched in 2018) is up and operating. … Read more

Many Worlds, Subterranean Edition

Scanning electron microscope blue-tinted image of nematode on biofilm, collected from Kopanang mine almost one mile below surface. (Borgonie, ELi)

Scanning electron microscope blue-tinted image of a nematode on bio-film, collected from Kopanang mine almost one mile below surface. (Borgonie, ELi)

One of the richest lines of research for those thinking about life beyond Earth has been the world of microscopic creatures that live in especially extreme and hostile environments here.  The realm of extremophiles has exploded in roughly the period that exoplanet discoveries have exploded, and both serve to significantly change our view of what’s possible in nature writ large.

I was reminded of this with the publication today of a paper on extreme life in the deep mines of South Africa.  This is not a brand new story, but rather significant step forward in a story that has implications galore for the search for life beyond Earth.

The extremophile chronology in South Africa goes like this:

First there was the microbe D. Audaxviator, “the Bold Traveler,” found living in light-less solitude more than two miles down a South African gold mine. Nothing alive had ever been found in rock fractures at that depth before.

Then there was H. Mephisto, the “Worm From Hell,” the first complex, multi-cellular creature (a type of worm) found living at almost equal depths in the same group of mines.

SEM of critters

Scanning electron microscope images of species of worms and a crustacean from Driefontein and Kopanang mines (Borgonie, ELi)

Now the researchers who made both of those discoveries have discovered a “veritable zoo” of multicellular creatures living in the wet rock fissures of the gold and diamond mines of the Witwaterstrand Basin of South Africa, roughly
a mile below the surface.

The earlier discoveries (reports about them were published in 2006 and 2011) had already changed scientists’ understanding of life in the rocky underworld. They had also given encouragement to those convinced that microbes and maybe multi-celled creatures can survive in fissures deep below the surface  of Mars and other moons and planets. The latest jackpot carries this shift in thinking further.

“It is very crowded in some places down under,” said Gaetan Borgonie of ELi, a Belgian nonprofit that studies extreme life, and of South Africa’s University of the Free State in Bloemfontein.

Borgonie, lead author of a paper about the “veritable zoo,” said that his discovery in 2011 of a new species of nematode at great depth had been dismissed by some as a “freak find.” But now, he said, “the fact that we have found in two mines, in different water, two ecosystems featuring several types of invertebrates hopefully puts that notion to rest as wrong.”

 

Scientists, including Borgonie (right), deep underground at Northam Platinum mine in South Africa. (Marc Kaufman)

Scientists, including Borgonie (right), deep underground at Northam Platinum mine in South Africa.

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