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Astronomers Ponder The Role Of Physics In Life

September 25, 2017 by  
Filed under Around The Net

Understanding the origin of life is arguably one of the most compelling quests for humanity. This quest has inevitably moved beyond the puzzle of life on Earth to whether there’s life elsewhere in the universe. Is life on Earth a fluke? Or is life as natural as the universal laws of physics?

Jeremy England, a biophysicist at the Massachusetts Institute of Technology, is trying to answer these profound questions. In 2013, he formulated a hypothesis that physics may spontaneously trigger chemicals to organize themselves in ways that seed “life-like” qualities.

Now, new research by England and a colleague suggests that physics may naturally produce self-replicating chemical reactions, one of the first steps toward creating life from inanimate substances.

This might be interpreted as life originating directly from the fundamental laws of nature, thereby removing luck from the equation. But that would be jumping the gun.

Life had to have come from something; there wasn’t always biology. Biology is born from the raw and lifeless chemical components that somehow organized themselves into prebiotic compounds, created the building blocks of life, formed basic microbes and then eventually evolved into the spectacular array of creatures that exist on our planet today.  

“Abiogenesis” is when something nonbiological turns into something biological and England thinks thermodynamics might provide the framework that drives life-like behavior in otherwise lifeless chemicals. However, this research doesn’t bridge life-like qualities of a physical system with the biological processes themselves, England said.

“I would not say I have done anything to investigate the ‘origin of life’ per se,” England told Live Science. “I think what’s interesting to me is the proof of principle – what are the physical requirements for the emergence of life-like behaviors?”

Self-organization in physical systems

When energy is applied to a system, the laws of physics dictate how that energy dissipates. If an external heat source is applied to that system, it will dissipate and reach thermal equilibrium with its surroundings, like a cooling cup of coffee left on a desk. Entropy, or the amount of disorder in the system, will increase as heat dissipates. But some physical systems may be  sufficiently out of equilibrium that they “self-organize” to make best use of an external energy source, triggering interesting self-sustaining chemical reactions that prevent the system from reaching thermodynamic equilibrium and thus maintaining an out-of-equilibrium state, England speculates. (It’s as if that cup of coffee spontaneously produces a chemical reaction that sustains a hotspot in the center of the fluid, preventing the coffee from cooling to an equilibrium state.) He calls this situation “dissipation-driven adaptation” and this mechanism is what drives life-like qualities in England’s otherwise lifeless physical system.

A key life-like behavior is self-replication, or (from a biological viewpoint) reproduction. This is the basis for all life: It starts simple, replicates, becomes more complex and replicates again. It just so happens that self-replication is also a very efficient way of dissipating heat and increasing entropy in that system.

In a study published July 18 in the journal Proceedings of the National Academy of Sciences,  England and co-author Jordan Horowitz tested their hypothesis. They carried out computer simulations on a closed system (or a system that doesn’t exchange heat or matter with its surroundings) containing a “soup” of 25 chemicals. Although their setup is very simple, a similar type of soup may have pooled on the surface of a primordial and lifeless Earth. If, say, these chemicals are concentrated and heated by an external source – a hydrothermal vent, for example – the pool of chemicals would need to dissipate that heat in accordance with the second law of thermodynamics. Heat must dissipate and the entropy of the system will inevitably increase.

Under certain initial conditions, he found that these chemicals may optimize the energy applied to the system by self-organizing and undergoing intense reactions to self-replicate. The chemicals fine-tuned themselves naturally. These reactions generate heat that obeys the second law of thermodynamics; entropy will always increase in the system and the chemicals would self-organize and exhibit the life-like behavior of self-replication.

“Essentially, the system tries a bunch of things on a small scale, and once one of them starts experiencing positive feedback, it does not take that long for it to take over the character of organization in the system,” England told Live Science.

This is a very simple model of what goes on in biology: chemical energy is burned in cells that are – by their nature – out of equilibrium, driving the metabolic processes that maintain life. But, as England admits, there’s a big difference between finding life-like qualities in a virtual chemical soup and life itself.

Sara Imari Walker, a theoretical physicist and astrobiologist at Arizona State University who was not involved in the current research, agrees.

“There’s a two-way bridge that needs to be crossed to try to bridge biology and physics; one is to understand how you get life-like qualities from simple physical systems and the other is to understand how physics can give rise to life,” Imari Walker told Live Science. “You need to do both to really understand what properties are unique to life and what properties are characteristic of things that you consider to be almost alive […] like a prebiotic system.”

Emergence of life beyond Earth?

Before we can even begin to answer the big question of whether these simple physical systems may influence the emergence of life elsewhere in the universe, it would be better to understand where these systems exist on Earth first.

“If, when you say ‘life,’ you mean stuff that is as stunningly impressive as a bacterium or anything else with polymerases and DNA, my work doesn’t yet tell us anything about how easy or difficult it is to make something that complex, so I shouldn’t speculate about what we’d be likely to find elsewhere than Earth,”  England said. (Polymerases are proteins that assemble DNA and RNA.)

This research doesn’t specifically identify how biology emerges from nonbiological systems, only that in some complex chemical situations, surprising self-organization occurs. These simulations do not consider other life-like qualities – such as adaptation to environment or reaction to stimuli. Also, this thermodynamics test on a closed system does not consider the role of information reproduction in life’s origins, said Michael Lässig, a statistical physicist and quantitative biologist at the University of Cologne in Germany.

“[This] work is indeed a fascinating result on non-equilibrium chemical networks but it is still a long way from a physics explanation of the origins of life, which requires the reproduction of information,” Lässig, who was not involved in the research, told Live Science.

There’s a critical role for information in living systems, added Imari Walker. Just because there appears to be natural self-organization exhibited by a soup of chemicals, it doesn’t necessarily mean living organization.

“I think there’s a lot of intermediate stages that we have to get through to go from simple ordering to having a full-on information processing architecture like a living cell, which requires something like memory and hereditary,” said Imari Walker. “We can clearly get order in physics and non-equilibrium systems, but that doesn’t necessarily make it life.”

To say England’s work could be the “smoking gun” for the origin of life is premature, and there are many other hypotheses as to how life may have emerged from nothing, experts said. But it is a fascinating insight into how physical systems may self-organize in nature. Now that researchers have a general idea about how this thermodynamic system behaves, it would be a nice next step to identify sufficiently out-of-equilibrium physical systems that naturally occur on Earth, England said.

Courtesy-Space

Astronomers Find Titanium Oxide On Aline Planet

September 22, 2017 by  
Filed under Around The Net

For the first time ever, titanium oxide has been spotted in an exoplanet’s skies, a new study reports.

Astronomers using the European Southern Observatory’s Very Large Telescope (VLT) in Chile detected the substance in the atmosphere of WASP-19b, a huge, scorching-hot planet located 815 light-years from Earth.

The presence of titanium oxide in the atmosphere of WASP-19b can have substantial effects on the atmospheric temperature structure and circulation,” study co-author Ryan MacDonald, an astronomer at the University of Cambridge in England, said in a statement.  

One possible effect is “thermal inversion.” If enough titanium oxide is present, the stuff can keep heat from entering or exiting an atmosphere, causing upper layers to be hotter than lower layers, researchers said. (This phenomenon occurs in Earth’s stratosphere, but the culprit is ozone, not titanium oxide.)

Artist’s illustration showing the exoplanet WASP-19b, whose atmosphere contains titanium oxide. In large enough quantities, titanium oxide can prevent heat from entering or escaping an atmosphere, leading to a “thermal inversion” in which temperatures are higher in the upper atmosphere than lower down.

WASP-19b is a bizarre world about the mass of Jupiter. The alien planet lies incredibly close to its host star, completing one orbit every 19 hours. As a result, WASP-19b’s atmospheric temperatures are thought to hover around 3,600 degrees Fahrenheit (2,000 degrees Celsius).

The research team — led by Elyar Sedaghati of the European Southern Observatory, the German Aerospace Center and the Technical University of Berlin — studied WASP-19b for more than a year using the VLT’s refurbished FORS2 instrument. These observations allowed them to determine that small amounts of titanium oxide, along with water and wisps of sodium, swirl around in the exoplanet’s blistering air.

“Detecting such molecules is, however, no simple feat,” Sedaghati said in the same statement. “Not only do we need data of exceptional quality, but we also need to perform a sophisticated analysis. We used an algorithm that explores many millions of spectra spanning a wide range of chemical compositions, temperatures, and cloud or haze properties in order to draw our conclusions.”

In addition to shedding new light on WASP-19b, the new study — which was published online today (Sept. 13) in the journal Nature — should improve researchers’ modeling of exoplanet atmospheres in general, team members said.

“To be able to examine exoplanets at this level of detail is promising and very exciting,” said co-author Nikku Madhusudhan, also of the University of Cambridge. 

Courtesy-Space

Can The James Webb Telescope Find Life In Our Solar System

September 18, 2017 by  
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The soon-to-launch James Webb Space Telescope will turn its powerful eye on two of the solar system’s top candidates for hosting alien life: the icy moons Enceladus and Europa, the agency confirmed in a statement this month.

Both Europa (a moon of Jupiter) and Enceladus (a moon of Saturn) are thought to possess subsurface oceans of liquid water beneath thick outer layers of ice. Both moons have also shown evidence of enormous plumes of liquid shooting up through cracks in the surface ice; these plumes could be caused by subsurface geysers, which could provide a source of heat and nutrients to life-forms there, scientists have said.

“We chose these two moons because of their potential to exhibit chemical signatures of astrobiological interest,” said Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy (AURA), who is leading an effort to use the telescope to study objects in Earth’s solar system.  

The James Webb Space Telescope, nicknamed “Webb,” will capture infrared light, which can be used to identify objects that generate heat but are not hot enough to radiate light (including humans, which is why many night-vision systems utilize infrared light). Researchers are hoping that Webb can help to identify regions on the surfaces of these moons where geologic activity, such as plume eruptions, are taking place. 

Enceladus’ plumes were studied in detail by the Cassini probe at Saturn. The spacecraft spotted hundreds of plumes, and even flew through some of them and sampled their composition. Europa’s plumes were spotted by the Hubble Space Telescope, and researchers know far less about them than those on Europa.

“Are they made of water ice? Is hot water vapor being released? What is the temperature of the active regions and the emitted water?” Geronimo Villanueva, lead scientist on the Webbobservation of Europa and Enceladus, said in the statement. “Webb telescope’s measurements will allow us to address these questions with unprecedented accuracy and precision.”

Webb’s observations will help pave the way for the Europa Clipper mission, a $2 billion orbital mission to the icy moon. Scheduled to launch in the 2020s, Europa Clipper will search for signs of life on Europa. The observations with Webb could identify areas of interest for the Europa Clipper mission to investigate, according to the statement.

As seen by Webb, the Saturn moon Enceladus will appear about 10 times smaller than Europa, so scientists will not be able to capture high-resolution views of Enceladus’ surface, according to the statement. However, Webb can still analyze the molecular composition of Enceladus’ plumes. 

But it’s also possible that the observations won’t catch a plume erupting from Europa’s surface; scientists don’t know how frequently these geysers erupt, and the limited observing time with Webb may not coincide with one of them. The telescope can detect organics — elements such as carbon that are essential to the formation of life as we know it — in the plumes. However, Villanueva cautioned that Webb does not have the power to directly detect life-forms in the plumes.

Webb is set to launch in 2018 and will orbit the sun at the L2 Lagrange point, which is about one million miles (1.7 million km) farther from the sun than the Earth’s orbit around the sun. The telescope will provide high-resolution views of both the very distant and very nearby universe. Scientists have already begun submitting ideas for objects or regions that should be observed using Webb’s powerful eye, and Europa and Enceladus are among the objects that are now guaranteed observing time.

Courtesy-Space

Project Blue Telescope Goes CrowdFunding

September 15, 2017 by  
Filed under Around The Net

The private space telescope initiative Project Blue launched a new crowdfunding campaign Sept. 6 in a second attempt to raise money for its mission to directly image Earth-like exoplanets. 

The initiative aims to launch a small space telescope into low-Earth orbit. The telescope will spy on our interstellar neighbor Alpha Centauri and image any Earth-like planets that might orbit the star system.

In support of Project Blue, BoldlyGo Institute and numerous organizations, including the SETI (Search for Extraterrestrial Intelligence) Institute, the University of Massachusetts Lowell and Mission Centaur, launched an IndieGoGo campaign to raise $175,000 over the next two months. The funds will be used to establish mission requirements, design the initial system architecture and test its capability for detecting exoplanets. Project leaders will also begin looking for potential partners who could manufacture parts of the space telescope, representatives said in a statement. 

“We’re very excited to pursue such an impactful space mission and, as a privately-funded effort, to include a global community of explorers and space science advocates in Project Blue from the beginning,” Jon Morse, CEO of BoldlyGo Institute, said in the statement.

Last year, Project Blue organizers attempted to raise $1 million through the crowdfunding platform Kickstarter, but the campaign was canceled after only $335,597 was contributed and Project Blue received none of the funds (as is Kickstarter’s policy). 

With the IndieGoGo campaign, however, the organizers have a more flexible goal and will be able to keep all contributions from supporters, even if the initial goal of $175,000 is not reached. So far, more than $45,000 has been raised through the campaign.

The neighboring star system Alpha Centauri is located only 4.37 light-years from Earth, making it a target for scientific research. Project Blue estimates it will take about $50 million to build the special-purpose telescope, which is planned to launch in 2021. 

The small space telescope will use a specialized coronagraph to block the bright glare of Alpha Centauri’s stars and detect planets that may be orbiting there. One planet, Proxima b, has already been detected around Proxima Centauri. 

However, Proxima b was discovered indirectly, by measuring the planet’s gravitational effect on its host star. Instead, the Project Blue telescope will be designed to directly image Earth-like planets in Alpha Centauri’s neighborhood.

 

Courtesy-Space

Do Trappist-1 Planets Have Enough Water For Alien Life

September 11, 2017 by  
Filed under Around The Net

The new study looks at how much ultraviolet (UV) radiation is received by each of the planets, because this could affect how much water the worlds could sustain over billions of years, according to the study. Lower-energy UV light can break apart water molecules into hydrogen and oxygen atoms on a planet’s surface, while higher-energy UV light (along with X-rays from the star) can heat a planet’s upper atmosphere and free the separated hydrogen and oxygen atoms into space, according to the study. (It’s also possible that the star’s radiation destroyed the planets’ atmospheres long ago.)

The researchers measured the amount of UV radiation bathing the TRAPPIST-1 planets using NASA’s Hubble Space Telescope, and in their paper they estimate just how much water each of the worlds could have lost in the 8 billion years since the system formed.

It’s possible that the six innermost planets (identified by the letters b, c, d, e, f and g), pelted with the highest levels of UV radiation, could have lost up to 20 Earth-oceans’ worth of water, according to the paper. But it’s also possible that the outermost four planets (e, f, g and h — the first three of which are in the star’s habitable zone) lost less than three Earth-oceans’ worth of water.

If the planets had little or no water to start with, the destruction of water molecules by UV radiation could spell the end of the planets’ habitability. But it’s possible that the planets were initially so rich in liquid water that, even with the water loss caused by UV radiation, they haven’t dried up,  according to one of the study’s authors, Michaël Gillon, an astronomer at the University of Liège in Belgium. Gillon was also lead author on two studies that first identified the seven TRAPPIST-1 planets.

“It is very likely that the planets formed much farther away from the star [than they are now] and migrated inwards during the first 10 million years of the system,” Gillon told Space.com in an email.

Farther away from their parent star, the planets might have formed in an environment rich in water ice, meaning the planets could have initially had very water-rich compositions.

“We’re talking about dozens, and maybe even hundreds of Earth-oceans, so a loss of 20 Earth-oceans wouldn’t matter much,” Gillon said. “What our results show is that even if the outer planets were initially quite water-poor like the original Earth, they could still have some water on their surfaces.”

Courtesy-Space

Will The James Webb Telescope Easily Find Earth Like Planets

August 17, 2017 by  
Filed under Around The Net

The James Webb Space Telescope (JWST), billed as “NASA’s premier observatory of the next decade,” could search for signs of an atmosphere on Proxima b. When it launches next year, JWST will be the most powerful space-based observatory yet, and the largest ever contrcuted. Its 6.5-meter mirror (nearly three times the size of the Hubble Space Telescope’s mirror) is expected to yield insights into the entire universe, ranging from the formation of planets and galaxies to peering at exoplanets in higher resolution than ever before.

There is only so much telescope time for JWST, however, and as with Hubble observations, astronomers will receive access on a competitive basis. Among the many proposals for the telescope that have emerged in recent months following NASA’s solicitation of science projects, a paper accepted for publication in the Astrophysical Journal (a draft version of which is available on Arxiv) suggests using the JWST to probe Proxima b’s atmosphere.

If such observations go forward, the telescope will provide an unparalleled view of Proxima b. JWST is optimized for infrared wavelengths, which can be used to examine a planet’s heat emissions. Because JWST will be orbiting the sun, it won’t be peering through Earth’s atmosphere, whose warmth can interfere with observations.

“Other telescopes are not able to do this,” Ignas Snellan, an astronomy researcher at the University of Leiden in the Netherlands and the paper’s lead author, told Seeker in an email. “Hubble is too small and works in the wrong wavelength range. Current ground-based telescopes cannot touch the mid-infrared because of very high thermal backgrounds, and are in a not enough stable environment, in contrast to JWST, which operates from space.”

The astronomers hope to use JWST to determine whether or not Proxima b has an atmosphere. Snellan said this will be very difficult, because the planet is very faint compared to its parent star. The research team therefore proposes looking for carbon dioxide.

The team’s method “looks for a striking signature that is expected from this molecule at 15 micron, that varies strongly from one wavelength to the next,” Snellan explained. “It will be very challenging, but we think doable.”

Finding carbon dioxide isn’t necessarily a sign of life as we know it. The gas is only found in trace amounts in Earth’s atmosphere (which is mostly made up of nitrogen and oxygen), even though carbon is the primary basis for life on our planet.

But carbon dioxide is a common gas on both Venus, which has a hellishly thick atmosphere, and Mars. Though the Red Planet once had a much thicker atmosphere long ago, today it is very thin. Scientists are still investigating how this atmospheric loss occurred, but suggest that the sun might have pushed light molecules out of Mars’ upper atmosphere that could not be held in by the planet’s gravity. Life may have existed on Mars in the ancient past, but scientists aren’t sure if that was possible then — or even now.

Might Proxima b be hospitable to life? Scientists are eager to look at the exoplanet in more detail, but Snellen notes that even better telescopes will be needed to answer that question. He suggests that the European Extremely Large Telescope could do the job after construction of the massive observatory is completed in the next decade. It would be able to probe for oxygen, which is a more definitive sign of life.

Meanwhile, the Breakthrough Starshot Initiative, which aims to one day send ultra-fast nanoprobes to the Alpha Centauri star system, is planning to soon begin examining the system’s three stars. The initiative recently partnered with the European Southern Observatory’s Very Large Telescope to look for worlds that could be habitable.

Courtesy-Space

Astronomers Find Stratrosphere On Alien World

August 10, 2017 by  
Filed under Around The Net

A huge, superhot alien planet has a stratrosphere, like Earth does, a new study suggests. 

“This result is exciting because it shows that a common trait of most of the atmospheres in our solar system — a warm stratosphere — also can be found in exoplanet atmospheres,” study co-author Mark Marley, of NASA’s Ames Research Center in California’s Silicon Valley, said in a statement.

“We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system,” Marley added. [Gallery: The Strangest Alien Planets] 

The research team, led by Thomas Evans of the University of Exeter in England, detected spectral signatures of water molecules in the atmosphere of WASP-121b, a gas giant that lies about 880 light-years from Earth. These signatures indicate that the temperature of the upper layer of the planet’s atmosphere increases with the distance from the planet’s surface. In the bottom layer of the atmosphere, the troposphere, the temperature decreases with altitude, study team members said.

WASP-121b lies incredibly close to its host star, completing one orbit every 1.3 days. The planet is a “hot Jupiter”; temperatures at the top of its atmosphere reach a sizzling 4,500 degrees Fahrenheit (2,500 degrees Celsius), researchers said.

“The question [of] whether stratospheres do or do not form in hot Jupiters has been one of the major outstanding questions in exoplanet research since at least the early 2000s,” Evans told Space.com. “Currently, our understanding of exoplanet atmospheres is pretty basic and limited. Every new piece of information that we are able to get represents a significant step forward.”

The discovery is also significant because it shows that atmospheres of distant exoplanets can be analyzed in detail, said Kevin Heng of the University of Bern in Switzerland, who is not a member of the study team. 

“This is an important technical milestone on the road to a final goal that we all agree on, and the goal is that, in the future, we can apply the very same techniques to study atmospheres of Earth-like exoplanets,” Heng told Space.com. “We would like to measure transits of Earth-like planets. We would like to figure out what type of molecules are in the atmospheres, and after we do that, we would like to take the final very big step, which is to see whether these molecular signatures could indicate the presence of life.”

Available technology does not yet allow such work with small, rocky exoplanets, researchers said. 

“We are focusing on these big gas giants that are heated to very high temperatures due to the close proximity of their stars simply because they are the easiest to study with the current technology,” Evans said. “We are just trying to understand as much about their fundamental properties as possible and refine our knowledge, and, hopefully in the decades to come, we can start pushing towards smaller and cooler planets.”

WASP-121b is nearly twice the size of Jupiter. The exoplanet transits, or crosses the face of, its host star from Earth’s perspective. Evans and his team were able to observe those transits using an infrared spectrograph aboard NASA’s Hubble Space Telescope.

“By looking at the difference in the brightness of the system for when the planet was not behind the star and when it was behind the star, we were able to work out the brightness and the spectrum of the planet itself,” Evans said. “We measured the spectrum of the planet using this method at a wavelength range which is very sensitive to the spectral signature of water molecules.”

The team observed signatures of glowing water molecules, which indicated that WASP-121b’s atmospheric temperatures increase with altitude, Evans said. If the temperature decreased with altitude, infrared radiation would at some point pass through a region of cooler water-gas, which would absorb the part of the spectrum responsible for the glowing effect, he explained. 

There have been hints of stratospheres detected on other hot Jupiters, but the new results are the most convincing such evidence to date, Evans said.

“It’s the first time that it has been done clearly for an exoplanet atmosphere, and that’s why it’s the strongest evidence to date for an exoplanet stratosphere,” he said. 

He added that researchers might be able to move closer to studying more Earth-like planets with the arrival of next-generation observatories such as NASA’s James Webb Space Telescope and big ground-based observatories such as the Giant Magellan Telescope (GMT), the European Extremely Large Telescope (E-ELT) and the Thirty Meter Telescope (TMT). JWST is scheduled to launch late next year, and GMT, E-ELT and TMT are expected to come online in the early to mid-2020s.

Courtesy-Space

Is Google Involved In Shady Research

July 19, 2017 by  
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A watchdog group has accused Google of funding academic research to try to influence public opinion and policymakers.

Campaign for Accountability (CfA), a Washington-based non-profit that recently launched the Google Transparency Project, said in a report that the company has thrown money at research papers in the US and Europe that appear to support its business interests, covering topics including antitrust, privacy, net neutrality, patents, and copyright.

“Google uses its immense wealth and power to attempt to influence policymakers at every level,” said Daniel Stevens, CfA executive director. “At a minimum, regulators should be aware that the allegedly independent legal and academic work on which they rely has been brought to them by Google.”

CfA claims that 329 papers published between 2005 and 2017 on public policy matters relevant to Google were in “some way” funded by the company, and alleges that authors of the papers – who were paid between $5,000 and $400,000 – did not disclose the source of their funding in 66 per cent of all cases.

Google has been quick to deny the accusations, and has slammed the CfA’s report as “highly misleading”.

In a blog post, Google’s director of public policy Leslie Miller said that the CfA had inflated numbers by attributing funding to Google when it actually came from associations to which Google.

She also said it was ironic that the CfA talked about transparency given that the watchdog’s only known backer is Oracle. 

“The irony of discussing disclosures and transparency with the Campaign for Accountability is that this group consistently refuses to name its corporate funders. And those backers won’t ‘fess up either,” wrote Miller.

“The one funder the world does know about is Oracle, which is running a well-documented lobbying campaign against us. In its own name and through proxies, Oracle has funded many hundreds of articles, research papers, symposia and reports.

“Oracle is not alone. You can easily find similar activity by companies and organisations funded by our competitors, like AT&T, the MPAA, ICOMP, FairSearch and dozens more, including hundreds of pieces directly targeting Google.”

Courtesy-TheInq

NASA Finds More Alien Worlds

June 28, 2017 by  
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NASA announced the latest crop of planet discoveries from the Kepler Space Telescope during a briefing on Monday morning June 19. 

The briefing will be at 11 a.m. EDT (1500 GMT) during the Kepler Science Conference at NASA’s Ames Research Center in California. You can watch the exoplanet announcement here, courtesy of NASA TV. NASA will livestream the conference.

The briefing will incude a panel of four experts, according to a statement by NASA: Mario Perez, Kepler program scientist in the Astrophysics Division of NASA’s Science Mission Directorate in Washington; Susan Thompson, Kepler research scientist at the SETI Institute in Mountain View, California; Benjamin Fulton, doctoral candidate at the University of Hawaii at Manoa and the California Institute of Technology; and Courtney Dressing, NASA Sagan Fellow at the California Institute of Technology. A question-and-answer session will follow.

Kepler has been hunting for extrasolar planets since its launch in 2009. This latest set of exoplanet candidates will use a more complete data set than ever before, with analysis of greater sophistication. The spacecraft started a new mission, called K2, after the failure of two reaction wheels that stabilized the spacecraft in 2013. The K2 mission was a modified version of the original planet-hunting mandate, seeking worlds around relatively nearby red dwarf stars. 

Newfound exoplanets are often listed as candidates because it can take time to verify that they are actually there. Kepler finds planets by observing the light of stars over a period of time, using a process called the transit method. If the light dims, then it’s possible a planet passed in front of it. The evidence for an exoplanet is considered stronger if the light dims more than once on a predictable schedule, indicating that something is in orbit around the star. 

Kepler was the first mission capable of seeing planets the size of Earth around other stars in the “habitable zone” — the region at a distance from a star where liquid water could exist without freezing or boiling away immediately. 

According to NASA, thus far Kepler has found 4,496 exoplanet candidates. Some 2,335 have been confirmed and 21 are Earth-size planets in the habitable zone. Since the mission was renamed K2, an additional 520 exoplanet candidates have been found, with 148 confirmed.

 

Courtesy-Space

Can Tiny Interstellar Probes Test The Panspermia Theory

June 9, 2017 by  
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Some of the first spacecraft that humanity sends to other solar systems may carry microscopic ambassadors from Earth.

The $100 million Breakthrough Starshot initiative is working to develop the technology required to accelerate tiny, sail-equipped probes to 20 percent the speed of light, using powerful lasers. 

If everything goes well, large fleets of these 1-gram spacecraft could begin launching toward Proxima b and other nearby alien worlds within 20 years or so, project representatives have said. The probes would characterize these planets in detail and search for signs of life, but some could perform other work as well.

For example, Breakthrough Starshot adviser Jeff Kuhn, a physicist at the University of Hawaii, said that the project offers a great opportunity to investigate the feasibility of interstellar panspermia — the idea that life might have spread from place to place throughout the Milky Way galaxy, and perhaps even the larger universe.

During a panel discussion on April 21 at the Breakthrough Discuss conference in Stanford, California, Kuhn noted that spores of the bacteria species Bacillus subtilis can survive for at least six years when exposed to the space environment. 

“I think it would be fun, on one of these disposable chips, to put a little colony of Bacillus, send it for 20 years, turn it on, give it some nutrients and see if it’s still alive, just to experimentally decide whether or not panspermia works over interstellar distances,” Kuhn said.

That comment elicited a response from audience member Philip Lubin, a physics professor at the University of California, Santa Barbara, who’s a key player in the development of Breakthrough Starshot’s laser-propulsion system.

“A part of our program — at least on the NASA side, because we haven’t cleared this with Breakthrough yet — is actually to put organisms to sleep, in stasis mode,” Lubin said at the conference. (Lubin and his group are also developing projects with the aid of NASA grant money.)

“And there are certain organisms known as C. elegans, which we’re going to embed human DNA into and send them out and then awaken them on arrival,” Lubin added, referring to a tiny roundworm species that’s a common study animal for biologists. “However, I expect that will be a highly controversial thing to do.”

The panspermia hypothesis posits that Earth life might have arrived, rather than originated, here.

This idea is not as fringe as you may think. For example, some scientists argue that, in the ancient past, the Martian environment was more conducive to life’s emergence than that of Earth. 

And it’s not terribly uncommon for the two planets to exchange material, in the form of rocks and dirt blasted into space by asteroid strikes. Orbital dynamics dictates that it’s much easier for Martian stuff to reach Earth than the other way around, so we may all be Martians, according to this line of thinking.

It may even be possible for life-forms to move from one star system to another, some panspermia adherents say. For example, hardy microscopic spores could be transported vast distances by stellar radiation pressure. Or frigid bodies orbiting far from their parent stars could come under the gravitational sway of a neighboring sun. [5 Bold Claims of Alien Life]

“We know that there are interstellar carriers: The Oort Cloud easily transfers from one solar system to another,” Kuhn said. (The Oort Cloud is our own solar system’s huge comet repository, which is believed to begin about 0.8 light-years from the sun.)

But there are a number of factors that could make it difficult for life to move through space. 

For example, putative Martian microbes ejected by an asteroid or comet strike would have to survive the intense heat and pressure of the impact, the harsh temperatures and high radiation levels of deep space and the rigors of atmospheric entry to have any hope of colonizing Earth. (The B. subtilis in the long-term experiment cited by Kuhn were in low Earth orbit, which has a more benign radiation environment thanks to our planet’s magnetic field.) 

Then, there’s the issue of time, which makes interstellar panspermia unlikely, according to Harvard University astronomy professor Dimitar Sasselov.

“With the short-lived universe we live in, the more likely scenario is that most of the planets that we’ll see life on are also the locations where it emerged from the planetary conditions,” Sasselov, who’s also the founding director of the Harvard Origins of Life Initiative, said during a different panel discussion at Breakthrough Discuss on April 20.

The transfer of organisms between nearby planets in the same solar system is feasible, he added. But interstellar panspermia “just takes too long, and it’s too far of a journey, and the probabilities currently, in the current universe, are just too small,” Sasselov said.

All of the above speculation assumes naturally occurring “accidental” panspermia. But it’s also possible that intelligent aliens could set panspermia in motion, either unintentionally (via contaminated spacecraft) or intentionally (in an effort to seed other worlds), some scientists have said.

Breakthrough Starshot, and projects like it, could give humanity this ability as well.

“We can be the panspermia which actually seeds other planets if we want,” Lubin said. “And it’s something to think about for the future.”

Now that would be controversial.

Courtesy-Space

Does Trappist-1 Planets Have Moons

June 5, 2017 by  
Filed under Around The Net

While we know of thousands of exoplanets and exoplanet candidates, the search for moons outside of our solar system is just beginning. We don’t have a confirmed exomoon discovery yet, but they’re bound to be out there.

Finding exomoons will help us better understand habitability on Earth. Some experts say a reason that life arose is our own moon is so close to the size of our planet, which stabilized its axis rotation. However, other studies (such as this 2011 American Astronomical Society paper quoted in a NASA Astrobiology story) argue that the gravitational influence of other planets in our solar system provide enough stability.

A new study looks at the possibilities of large moons in TRAPPIST-1, a notoriously crowded exoplanet system that may have habitable planets within it. Earlier this year, observations from NASA’s Spitzer Space Telescope indicated that seven planets here could be rocky and have liquid water on their surfaces, making TRAPPIST-1 the system with the most potentially habitable planets.

But even before NASA’s discovery, TRAPPIST-1 was known and pondered by scientists, including the author of the new paper, Stephen Kane, an associate professor of astronomy at San Francisco State University who specializes in exoplanets.

“I have several publications now on exomoons, and for many years I’ve been thinking about how the ability of a planet to host a moon scales with the presence of nearby planets and proximity to the host star,” Kane said in an e-mail. “The discovery of the TRAPPIST-1 system prompted me to finally calculate whether or not planets in compact planetary systems can actually harbor moons.”

Kane cautioned that scientists can’t overly attribute Earth’s habitability to our moon, because Earth is the only known habitable planet. However, the moon does have an important role: It creates significant tides on Earth, which probably helped create the tidal pools in which early biochemistry could occur.

“The presence of the moon has helped to stabilize changes in the tilt of the Earth’s rotational axis, which in turn creates longer periods of climate stability,” Kane added. “So although it’s difficult to say what the Earth would be like without a moon, we can certainly describe ways in which it has positively influenced our present environment.”

For TRAPPIST-1, Kane found that the planets are so tightly packed together that large moons would likely be impossible. While the rotational axes of the planets would quickly change and have more chaotic climates, he said, life could still evolve — it just might take a longer time.

Kane’s methodology involved studying the influences of two parameters: the Hill radius, or the area in space in which a planet exerts gravitational influence based on its mass and distance from the host star, and the Roche limit, which identifies where the gravitational effect near a planet is too strong for a moon to survive.

“A moon can only exist around a planet if it lies between these two boundaries: too close and it will be destroyed, too far away and it will escape the gravitational influence of the planet,” Kane said. “The results of the study described in my paper show that, for most planets in compact planetary systems, the Hill radius and Roche limit are close enough to each other that there is no space in which a moon can exist and so such planets cannot have moons in orbit around them.”

Courtesy-Fud

Do Any Trappist 1 Planets Have Moons

May 19, 2017 by  
Filed under Around The Net

While we know of thousands of exoplanets and exoplanet candidates, the search for moons outside of our solar system is just beginning. We don’t have a confirmed exomoon discovery yet, but they’re bound to be out there.

Finding exomoons will help us better understand habitability on Earth. Some experts say a reason that life arose is our own moon is so close to the size of our planet, which stabilized its axis rotation. However, other studies (such as this 2011 American Astronomical Society paper quoted in a NASA Astrobiology story) argue that the gravitational influence of other planets in our solar system provide enough stability.

A new study looks at the possibilities of large moons in TRAPPIST-1, a notoriously crowded exoplanet system that may have habitable planets within it. Earlier this year, observations from NASA’s Spitzer Space Telescope indicated that seven planets here could be rocky and have liquid water on their surfaces, making TRAPPIST-1 the system with the most potentially habitable planets.

But even before NASA’s discovery, TRAPPIST-1 was known and pondered by scientists, including the author of the new paper, Stephen Kane, an associate professor of astronomy at San Francisco State University who specializes in exoplanets.

“I have several publications now on exomoons, and for many years I’ve been thinking about how the ability of a planet to host a moon scales with the presence of nearby planets and proximity to the host star,” Kane said in an e-mail. “The discovery of the TRAPPIST-1 system prompted me to finally calculate whether or not planets in compact planetary systems can actually harbor moons.”

Kane cautioned that scientists can’t overly attribute Earth’s habitability to our moon, because Earth is the only known habitable planet. However, the moon does have an important role: It creates significant tides on Earth, which probably helped create the tidal pools in which early biochemistry could occur.

“The presence of the moon has helped to stabilize changes in the tilt of the Earth’s rotational axis, which in turn creates longer periods of climate stability,” Kane added. “So although it’s difficult to say what the Earth would be like without a moon, we can certainly describe ways in which it has positively influenced our present environment.”

For TRAPPIST-1, Kane found that the planets are so tightly packed together that large moons would likely be impossible. While the rotational axes of the planets would quickly change and have more chaotic climates, he said, life could still evolve — it just might take a longer time.

Kane’s methodology involved studying the influences of two parameters: the Hill radius, or the area in space in which a planet exerts gravitational influence based on its mass and distance from the host star, and the Roche limit, which identifies where the gravitational effect near a planet is too strong for a moon to survive.

“A moon can only exist around a planet if it lies between these two boundaries: too close and it will be destroyed, too far away and it will escape the gravitational influence of the planet,” Kane said. “The results of the study described in my paper show that, for most planets in compact planetary systems, the Hill radius and Roche limit are close enough to each other that there is no space in which a moon can exist and so such planets cannot have moons in orbit around them.”

Courtesy-Space

Is Ridley Scott Right About An Alien Encounter

May 16, 2017 by  
Filed under Around The Net

Film director Ridley Scott, who delights in terrifying moviegoers with his cinematic blend of horror and science fiction, suggested in a recent interview that the scary prospect of belligerent invading aliens might transcend the realm of sci-fi. According to Scott, hundreds of alien species are “out there” on distant worlds, and Earth’s inhabitants should prepare for the worst if they ever decide to visit our planet.

One scientist, though, says that Scott’s information about such hostile, and abundant, aliens is off-base and unsupported.

Scott told Agence France-Presse (AFP) about his belief in “superior beings,” while fielding questions about his latest movie, “Alien: Covenant,” opening in theaters in the U.S. on May 19. He warned that any extraterrestrial travelers who are technologically advanced enough to show up on our doorstep would likely be very intelligent and very hostile. And unlike the scenarios that dominate movies — if we go toe-to-toe with these invaders, we probably won’t be the victors, he said.

“If you are stupid enough to challenge them you will be taken out in three seconds,” Scott told AFP. [Greetings, Earthlings! 8 Ways Aliens Could Contact Us]

In the interview, Scott explained that “the experts” estimate there are “between 100 and 200 entities” on other planets, following what could be a similar evolutionary path to ours. And if they get here first, our best bet would be to “run for it,” AFP reported.

The possibility of intelligent, technologically adept alien life has intrigued science-fiction writers and readers since the French writer Voltaire published his short story “Micromégas” in 1752, describing two extraterrestrial visitors to Earth — one from the planet Saturn and one from a planet orbiting the star Sirius.

Scott has made his own contributions to the genre, most notably with his string of “Alien” movies, which imagine a highly adaptable and morphologically flexible alien species. The so-called xenomorphs breed quickly and are ruthlessly efficient at overpowering humans, either swiftly dismembering them or cultivating them as hosts for their young — luckily, in isolated locations that are far from our home planet.

But though Scott is a skilled sci-fi yarn-spinner, his assessment of real-world alien threats could use a script doctor, according to Seth Shostak, senior astronomer with the SETI Institute, a research institution dedicated to the search for communication signals produced by intelligent extraterrestrial life.

To begin with, Scott’s “expert” estimate of 100 to 200 “entities” is entirely unsubstantiated, Shostak told Live Science.

“We have absolutely no data that would tell you what that number might be,” he said.

In fact, estimates based on data about known planets and galaxies suggest that the actual number of intelligent extraterrestrial life forms could, in fact, be significantly higher. With approximately 1 trillion planets in our galaxy alone, and about 2 trillion more galaxies, that adds up to…well, it’s a lot of planets, Shostak said.

To narrow the search a bit, scientists could start by just looking at the trillion planets in our own galaxy, he said. Only a fraction of those planets might be capable of supporting life — perhaps 1 in 10. And maybe only 1 in 1,000 could produce and support life more complex than bacteria, he said.

That gives us about a billion planets in our galaxy that might harbor some type of intelligent life. But over time, life on many of those planets could have already waxed and waned — self-destructed or been wiped out. Perhaps only one planet in a million of those intelligent-life-harboring worlds still support life capable of contacting humans. That adds up to about 1,000 planets that could potentially hold intelligent, extraterrestrial species, Shostak told Live Science.

However, if a planet is more than 70 light-years from Earth, it hasn’t yet received any radio signals from us. Its residents, no matter how technologically adept, wouldn’t know humans exist yet. Even if long-distance observations of Earth told them we had oxygen in our atmosphere — and thereby some form of life — they’d be very unlikely to travel all this way to look at what might amount to just a lot of bacteria, Shostak added. 

Neither would extraterrestrials be likely to invade our solar system merely to steal our resources, he said. If a civilization is advanced enough that they’ve exhausted all the resources of their entire star system — every planet, moon and asteroid — and are all out of natural materials, they’re probably at a stage where they could create what they needed from simpler materials in their own backyard, rather than traveling across the galaxy for a very limited supply, Shostak said.

It’s equally unlikely they’d be showing up because they thought humans would make an excellent addition to their diet, he said.

“To do that, they would have to know that we had something interesting within our bodies that they could metabolize, and their body chemistry would probably be very different from ours,” Shostak said.

But Scott did get one thing right: If extraterrestrials are capable of building spacecraft that can transport them to our planet, they certainly would be technologically “superior” to people, Shostak said. And if he saw a spaceship suddenly appear, Shostak admitted that he’d probably do as Scott suggested — and just “run for it.”

Courtesy-Space

Is Oxygen Needed To Support Alien Life?

May 4, 2017 by  
Filed under Around The Net

The hot springs of Yellowstone National Park may be extreme environments, but they are host to a diversity of microbes that could shed light on the evolution of life on Earth and, perhaps, what lurks on distant planets. 

While photosynthetic life cannot tolerate the high temperatures of hot springs, microorganisms that are chemosynthetic — meaning they rely solely on chemicals, rather than sunshine, as their energy source — do well there. Many of these peculiar microbes are believed to be the closest modern relatives to the earliest life on our planet. 

“Chemosynthetic microorganisms provide useful models for understanding how life might persist in extraterrestrial systems, like the subsurface of Europa, for instance, where light energy will not be available but abundant sources of chemical energy might be,” said Daniel Colman, a geomicrobiologist at Montana State University in Bozeman.

In 2014, Colman and his colleagues collected samples from chemosynthetic microbial communities in 15 hot springs in Yellowstone National Park. Hot springs are complex environments, where nutrient availability varies widely, even within the same hot spring. Colman analyzed how these variations might shape the kinds of chemosynthetic communities that might exist at any given spot. 

Colman and his team detailed their findings in the paper “Ecological differentiation in planktonic and sediment-associated chemotrophic microbial populations in Yellowstone hot springs” in the journal FEMS Microbiology Ecology.

The researchers looked at microorganisms that were either planktonic, that is, free-swimming, or those living in sediment, and then examined the chemistry of the water and the mineralogy of the sediments.

They focused on substances known as oxidants, which help organisms capture energy by stripping electrons from nutrients. Whereas humans and many other organisms rely on oxygen to act as their primary oxidant, chemosynthetic microbes rely on other oxidants that provide less energy, such as forms of iron and sulfur that are oxidized (oxidized materials have lost electrons).

The scientists found that planktonic communities in Yellowstone were dominated by bacteria that are microaerophiles, which need oxygen to survive but at concentrations lower than is present in Earth’s atmosphere. In contrast, sediment communities in Yellowstone were dominated by chemosynthetic microbes that rely on inorganic substances such as elemental sulfur or oxidized iron as their oxidants. 

These findings shed light on how and why hot spring microbes in sediments differ from those in the water. Microbes living in water that has been exposed to, and mixed with air, can use oxygen from the air as their oxidant, while microbes in sediments that are likely oxygen-poor have to make do with other kinds of oxidants. The researchers expect that early life on Earth was limited by the availability of oxidants and had to make do with what was around them. The same might be true of life elsewhere in the Universe.

“Understanding the present-day distributions of microorganisms as they relate to environmental factors can provide an idea of how life evolved in response to changing environments over Earth’s history and over the history of life’s evolution,” Colman said. 

Colman is especially interested in the subsurface microbial communities at Yellowstone, since they may, in some ways, resemble extraterrestrial settings on places like Europa. Nothing is known of the nature, or even existence of, a shallow, high-temperature subsurface biosphere in Yellowstone National Park, since drilling of any kind is prohibited on national park lands. 

NASA is interested in this research because developing an understanding of life in the hot springs of Yellowstone has the potential to shed light on how life may thrive in extraterrestrial environments that are similarly high in temperature and pressure and low in nutrients, Colman said. “These environments are understudied in astrobiology research, but hold tremendous promise as accessible analogs for extraterrestrial habitable environments that might be present on Enceladus, Mars, or Europa,” Colman said.

For instance, just as the sediments of Yellowstone’s hot springs are low in oxygen, “we would expect that life in other planetary body subsurface environments would likely be plagued by a chronic lack of oxidants, like oxygen, and would need to make do with oxidants that provide less energy,” Colman said.

Courtesy-Fud

Is Silicon Based Life Possible?

April 26, 2017 by  
Filed under Around The Net

Science fiction has long imagined alien worlds inhabited by silicon-based life, such as the rock-eating Horta from the original Star Trek series. Now, scientists have for the first time shown that nature can evolve to incorporate silicon into carbon-based molecules, the building blocks of life on Earth.

As for the implications these findings might have for alien chemistry on distant worlds, “my feeling is that if a human being can coax life to build bonds between silicon and carbon, nature can do it too,” said the study’s senior author Frances Arnold, a chemical engineer at the California Institute of Technology in Pasadena. The scientists detailed their findings recently in the journal Science.

Carbon is the backbone of every known biological molecule. Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.  

Still, researchers have long speculated that alien life could have a completely different chemical basis than life on Earth. For example, instead of relying on water as the solvent in which biological molecules operate, perhaps aliens might depend on ammonia or methane. And instead of relying on carbon to create the molecules of life, perhaps aliens could use silicon.

Carbon and silicon are chemically very similar in that silicon atoms can also each form bonds with up to four other atoms simultaneously. Moreover, silicon is one of the most common elements in the universe. For example, silicon makes up almost 30 percent of the mass of the Earth’s crust, and is roughly 150 times more abundant than carbon in the Earth’s crust. 

Scientists have long known that life on Earth is capable of chemically manipulating silicon. For instance, microscopic particles of silicon dioxide called phytoliths can be found in grasses and other plants, and photosynthetic algae known as diatoms incorporate silicon dioxide into their skeletons. However, there are no known natural instances of life on Earth combining silicon and carbon together into molecules.

Still, chemists have artificially synthesized molecules comprised of both silicon and carbon. These organo-silicon compounds are found in a wide range of products, including pharmaceuticals, sealants, caulks, adhesives, paints, herbicides, fungicides, and computer and television screens. Now, scientists have discovered a way to coax biology to chemically bond carbon and silicon together. 

“We wanted to see if we could use what biology already does to expand into whole new areas of chemistry that nature has not yet explored,” Arnold said. [Facts About Silicon]

The researchers steered microbes into creating molecules never before seen in nature through a strategy known as ‘directed evolution,’ which Arnold pioneered in the early 1990s. Just as farmers have long modified crops and livestock by breeding generations of organisms for the traits they want to appear, so too have scientists bred microbes to create the molecules they desire. Scientists have used directed evolutionary strategies for years to create household goods such as detergents, and to develop environmentally-friendly ways to make pharmaceuticals, fuels and other industrial products. (Conventional chemical manufacturing processes can require toxic chemicals; in contrast, directed evolutionary strategies use living organisms to create molecules and generally avoid chemistry that would prove harmful to life.)

Arnold and her team — synthetic organic chemist Jennifer Kan, bioengineer Russell Lewis, and chemist Kai Chen — focused on enzymes, the proteins that catalyze or accelerate chemical reactions. Their aim was to create enzymes that could generate organo-silicon compounds. 

“My laboratory uses evolution to design new enzymes,” Arnold said. “No one really knows how to design them — they are tremendously complicated.  But we are learning how to use evolution to make new ones, just as nature does.”

First, the researchers started with enzymes they suspected could, in principle, chemically manipulate silicon. Next, they mutated the DNA blueprints of these proteins in more or less random ways and tested the resulting enzymes for the desired trait. The enzymes that performed best were mutated again, and the process was repeated until the scientists reached the results they wanted.

Arnold and her colleagues started with enzymes known as heme proteins, which all have iron at their hearts and are capable of catalyzing a wide variety of reactions. The most widely recognized heme protein is likely hemoglobin, the red pigment that helps blood carry oxygen. 

After testing a variety of heme proteins, the scientists concentrated on one from Rhodothermus marinus, a bacterium from hot springs in Iceland. The heme protein in question, known as cytochrome c, normally shuttles electrons to other proteins in the microbe, but Arnold and her colleagues found that it could also generate low levels of organo-silicon compounds. 

After analyzing cytochrome c’s structure, the researchers suspected that only a few mutations might greatly enhance the enzyme’s catalytic activity. Indeed, only three rounds of mutations were enough to turn this protein into a catalyst that could generate carbon-silicon bonds more than 15 times more efficiently than the best synthetic techniques currently available. The mutant enzyme could generate at least 20 different organo-silicon compounds, 19 of which were new to science, Arnold said. It remains unknown what applications people might be able to find for these new compounds.

“The biggest surprise from this work is how easy it was to get new functions out of biology, new functions perhaps never selected for in the natural world that are still useful to human beings,” Arnold said. “The biological world always seems poised to innovate.”

In addition to showing that the mutant enzyme could self-generate organo-silicon compounds in a test tube, the scientists also showed that E. coli bacteria, genetically engineered to produce the mutant enzyme within themselves, could also create organo-silicon compounds. This result raises the possibility that microbes somewhere could have naturally evolved the ability to create these molecules.

“In the universe of possibilities that exist for life, we’ve shown that it is a very easy possibility for life as we know it to include silicon in organic molecules,” Arnold said. “And once you can do it somewhere in the universe, it’s probably being done.” 

It remains an open question why life on Earth is based on carbon when silicon is more prevalent in Earth’s crust. Previous research suggests that compared to carbon, silicon can form chemical bonds with fewer kinds of atoms, and it often forms less complex kinds of molecular structures with the atoms that it can interact with. By giving life the ability to create organo-silicon compounds, future research can test why life here or elsewhere may or may not have evolved to incorporate silicon into biological molecules.

In addition to the astrobiology implications, the researchers noted that their work suggests biological processes could generate organo-silicon compounds in ways that are more environmentally friendly and potentially much less expensive than existing methods of synthesizing these molecules. For example, current techniques for creating organo-silicon compounds often require precious metals and toxic solvents.

The mutant enzyme also makes fewer unwanted byproducts. In contrast, existing techniques typically require extra steps to remove undesirable byproducts, adding to the cost of making these molecules.

“I’m talking to several chemical companies right now about potential applications for our work,” Arnold said. “These compounds are hard to make synthetically, so a clean biological route to produce these compounds is very attractive.”

Future research can explore what advantages and disadvantages the ability to create organo-silicon compounds might have for organisms. “By giving this capability to an organism, we might see if there is, or is not, a reason why we don’t stumble across it in the natural world,” Arnold said.

The research was funded by the National Science Foundation, the Caltech Innovation Initiative program, and the Jacobs Institute for Molecular Engineering for Medicine at Caltech.

Courtesy-Space

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