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Does Pluto Have Buried Oceans

December 7, 2017 by  
Filed under Around The Net

Our solar system may harbor many more potentially habitable worlds than scientists had thought.

Subsurface oceans could still slosh beneath the icy crusts of frigid, faraway worlds such as the dwarf planets Pluto and Eris, kept liquid by the heat-generating tug of orbiting moons, according to a new study. 

“These objects need to be considered as potential reservoirs of water and life,” lead author Prabal Saxena, of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “If our study is correct, we now may have more places in our solar system that possess some of the critical elements for extraterrestrial life.”  

Underground oceans are known, or strongly suspected, to exist on a number of icy worlds, including the Saturn satellites Titan and Enceladus and the Jovian moons Europa, Callisto and Ganymede. These oceans are kept liquid to this day by “tidal heating”: The powerful gravitational pull of these worlds’ giant parent planets stretches and flexes their interiors, generating heat via friction.

The new study suggests something similar may be going on with Pluto, Eris and other trans-Neptunian objects (TNOs).

Many of the moons around TNOs are thought to have coalesced from material blasted into space when objects slammed into their parent bodies long ago. That’s the perceived origin story for the one known satellite of Eris (called Dysnomia) and for Pluto’s five moons (as well as for Earth’s moon). 

Such impact-generated moons generally begin their lives in relatively chaotic orbits, team members of the new study said. But over time, these moons migrate to more-stable orbits, and as this happens, the satellites and the TNOs tug on each other gravitationally, producing tidal heat.

Saxena and his colleagues modeled the extent to which this heating could warm up the interiors of TNOs — and the researchers got some intriguing results.

“We found that tidal heating can be a tipping point that may have preserved oceans of liquid water beneath the surface of large TNOs like Pluto and Eris to the present day,” study co-author Wade Henning, of NASA Goddard and the University of Maryland, said in the same statement.

As the term “tipping point” implies, there’s another factor in play here as well. It’s been widely recognized that TNOs could harbor buried oceans thanks to the heat produced by the decay of the objects’ radioactive elements. But just how long such oceans could persist has been unclear. This type of heating peters out eventually, as more and more radioactive material decays into stable elements. And the smaller the object, the faster it cools down.

Tidal heating may do more than just lengthen subsurface oceans’ lives, researchers said.Next Up

“Crucially, our study also suggests that tidal heating could make deeply buried oceans more accessible to future observations by moving them closer to the surface,” said study co-author Joe Renaud, of George Mason University in Virginia. “If you have a liquid-water layer, the additional heat from tidal heating would cause the next adjacent layer of ice to melt.” 

The new study was published online last week in the journal Icarus

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Arecibo Observatory To Keep Ticking

December 6, 2017 by  
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Scientists’ reactions range from joy to cautious optimism at the news that the iconic Arecibo Observatory — often used to pose the question, “Are we alone?” — will continue operations after enduring a powerful hurricane and dramatic budget constraints.

The Arecibo Observatory in Puerto Rico celebrated its 50th anniversary in 2013. During its long history, Arecibo has served as the home base to large-scale astronomical research projects and has joined the search for extraterrestrial intelligence with programs like the “Arecibo Message” of 1974, which was the first interstellar message sent from Earth that was intended for alien life-forms who may have been capable of listening. In 1993, Joseph Hooton Taylor Jr. and Russell Hulse won the Nobel Prize in physics for using Arecibo to make the first-ever observation of a binary pulsar star system. The study of the circling stellar cores from Arecibo provided early, indirect evidence of gravitational waves, which are currently in the scientific spotlight.

In popular fiction, Arecibo is the well-known setting of Carl Sagan’s book “Contact” (Simon & Schuster, 1985) and the subsequent 1997 film by the same name, about humanity’s interaction with aliens. It was also the scene of James Bond’s climactic fight in the film “GoldenEye” (1995).

Until recently, the observatory also functioned as the largest radio dish telescope in the world, with a diameter of 1,000 feet (305 meters).

Arecibo’s legacy of prominence also includes the first use of radar ranging to determine an asteroid’s distance from Earth when crossing the planet’s orbit, early mapping of several objects in the solar system and the first detections of planets in orbit around other stars, according to Stanford Research Institute International, which manages the observatory alongside the National Science Foundation (NSF), the Universities Space Research Association and the Universidad Metropolitana in San Juan.

But in the last few years, Arecibo has been at risk of losing funding from NSF, which, according to the foundation, stems from budget constraints. Then on Sept. 20, Hurricane Maria hit the island of Puerto Rico as a Category 4 storm, causing the entire facility to lose power and adding to concerns that operations might permanently shut down, due to the cost of recovery.

“I am extremely happy to hear about the decision to continue scientific operations at Arecibo,” Jason W. T. Hessels, associate scientist at the Netherlands Institute for Radio Astronomy (ASTRON), told Space.com in an email. “This facility has a long and storied scientific history, and remains on the cutting edge in many areas.”  

“Arecibo Observatory is uniquely capable of performing many atmospheric studies that cannot be conducted at any other facility worldwide,” Frank T. Djuth, president of Geospace Research. in El Segundo, California, told Space.com in an email. “These include the continuous passage of acoustic gravity waves over the Observatory and instabilities in the photoelectrons produced in the upper atmosphere. Although Arecibo will remain open, there is concern that federal funding of Arecibo research will disappear.”

Ellen Howell from the Lunar and Planetary Laboratory at the University of Arizona, has, like Djuth, performed research at Arecibo. Howell was pleased about NSF’s decision to continue managing the facility for the next five years. In an email to Space.com, Howell said she was a staff scientist at the observatory from 1999 to 2015 — almost 16 years — and continues to use the telescope for her research while collaborating with scientists currently working there.

While she was relieved, Howell remains concerned about Arecibo’s future: According to NSF’s earlier budget statement, the foundation will significantly reduce funding — from $8.3 million to just $2 million a year — by the end of the proposed five-year project period.

“In consideration of these reductions, operations and activities cannot be sustained at current levels without external sources of funding,” NSF officials said in the statement.

Howell believes that “the operation mode would have to change in a major way,” since the funding provides “critical support” for Arecibo’s infrastructure and operation.

“The science being carried out at Arecibo Observatory is unique,” added Howell, “particularly the solar system studies, and cannot be done at other facilities such as ALMA or the Chinese telescope FAST.” [Huge Earth-Passing Asteroid an ‘Entirely New Beast’]

Nevertheless, the scientific community remains hopeful that Arecibo can continue facilitating innovations in science.

“With continued operations,” Hessels said, “and hopefully also an increased budget to equip the telescope with new, state-of-the-art electronics in the coming years, Arecibo is bound to continue its heritage of fundamental discoveries.”

Courtesy-Space

A Planets Equator May Inhibit Astronomers From Finding Life

December 5, 2017 by  
Filed under Around The Net

Spotting signs of life in an alien planet’s atmosphere may be tougher than scientists had thought.

One prominent such “biosignature” target, ozone, may get trapped near the equators of Proxima b, TRAPPIST-1d and other potentially habitable worlds that orbit close to their host stars, making the gas hard to detect from afar, a new study suggests.

“Absence of traces of ozone in future observations does not have to mean there is no oxygen at all,” study lead author Ludmila Carone, of the Max Planck Institute for Astronomy in Heidelberg, Germany, said in a statement. “It might be found in different places than on Earth, or it might be very well hidden.”

Ozone is an unstable molecule that consists of three oxygen atoms. Here on Earth, the stuff is generally produced in the atmosphere after ultraviolet (UV) radiation from the sun splits “normal” diatomic oxygen (O2). 

The vast majority of Earth’s O2 is generated by living organisms — plants and photosynthetic microbes — so ozone serves as a sort of secondary biomarker, at least for Earth-like life.

Earth’s atmospheric flows distribute most ozone relatively evenly into our planet’s famous ozone layer, which helps shield life from harmful UV radiation. So hypothetical aliens studying Earth from afar with powerful telescopes would have a good chance of detecting the gas.

But the situation is likely different on Proxima b, TRAPPIST-1d and other tidally locked worlds — those that always show the same face to their parent stars, and therefore have a “dayside” and a “nightside” — according to Carone and her colleagues. (Tidal locking is a consequence of a very tight orbit; TRAPPIST-1d and Proxima b complete one lap around their stars every four Earth days and 11 Earth days, respectively.)

Modeling work performed by the researchers indicates that, on planets with orbital periods of 25 Earth days or less, airflows tend to concentrate ozone (and other photochemically produced molecules) in an equatorial band.

“We all knew from the beginning that the hunt for alien life will be a challenge,” Carone said. “As it turns out, we are only just scratching the surface of how difficult it really will be.”

The new results also suggest that worlds like Proxima b don’t have a global ozone layer. That may or may not have a significant negative effect on their habitability, Carone said.

“Proxima b and TRAPPIST-1d orbit red dwarfs, reddish stars that emit very little harmful UV light to begin with,” she said in the statement. (Tidally locked planets pretty much have to orbit dim dwarf stars to be habitable; worlds that orbit so close to sunlike stars are far too hot to host life as we know it.) 

“On the other hand, these stars can be very temperamental, and prone to violent outbursts of harmful radiation, including UV,” she added. “There is still a lot that we don’t know about these red dwarf stars. But I’m confident we will know much more in five years.”

In five years, astronomers will have a lot more data — from telescopes such as NASA’s $8.8 billion James Webb Space Telescope, which is scheduled to launch in early 2019 — to inform their inferences about the habitability of red-dwarf planets. And advances in modeling techniques over this time span should help as well, study team members said.

The new study will appear in the Feb. 1, 2018, issue of the journal Monthly Notices of the Royal Astronomical Society.

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Does Space Dust Transport Life Around The Galaxy

November 29, 2017 by  
Filed under Around The Net

It may not take an asteroid strike to transport life from one planet to another.

Fast-moving dust could theoretically knock microbes floating high up in a world’s atmosphere out into space, potentially sending the bugs on a trip to another planet — perhaps even one orbiting a different star, according to a new study.

“The proposition that space-dust collisions could propel organisms over enormous distances between planets raises some exciting prospects of how life and the atmospheres of planets originated,” study author Arjun Berera, a professor in the School of Physics and Astronomy at the University of Edinburgh in Scotland, said in a statement.  

“The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life,” Berera added.

Berera isn’t the first person to propose that organisms could hop from world to world throughout the cosmos. That basic idea, known as panspermia, has been around for thousands of years. It has received renewed interest recently, however, as scientists have demonstrated that some organisms — such as certain bacteria, and micro-animals known as tardigrades — can survive for extended periods in space.

But researchers have generally regarded comet or asteroid impacts as the only viable way to get simple life-forms off a planet and into space, whence they could perhaps blunder their way to a different habitable world. (We won’t consider here the “directed panspermia” idea, which posits that intelligent aliens have seeded the galaxy with life or its building blocks.)

Comet or asteroid impacts do indeed blast rocks from planet to planet. Scientists have found numerous meteorites here on Earth that were once part of Mars — including one known as ALH84001, which some scientists think may preserve signs of ancient Red Planet life.

In the new study, Berera examined what likely happens when bits of interplanetary dust hit molecules and particles in Earth’s atmosphere. This space stuff rains down on us every day, hitting the planet at speeds of between 22,400 mph and 157,000 mph (36,000 to 253,000 km/h).

He calculated that small particles floating at least 93 miles (150 kilometers) above Earth’s surface could theoretically get knocked into space by this wandering dust. It’s unclear if microbes could survive such violent collisions; that’s an area ripe for future research, Berera wrote in the new paper, which has been accepted for publication in the journal Astrobiology. (You can read the study for free at the online preprint site arXiv.org.)

And even if these micro-impacts are invariably fatal, they could still help life get a foothold on other worlds by sending its building blocks — the complex molecules that make up a microbe corpse, for example — out into space, he added.

Courtesy-Space

Will The Arecibo Observatory Close

November 27, 2017 by  
Filed under Around The Net

Two months since Hurricane Maria wreaked havoc on Puerto Rico, most of the island is still recovering from the disaster — including the Arecibo Observatory, home of the world’s second-largest radio telescope. This week, the dozens of astronomers and other staff at the facility have some good news to celebrate: The Arecibo Observatory will remain open after years of being on the chopping block.

The National Science Foundation (NSF), which funds approximately two-thirds of the observatory’s annual budget of $12 million, announced on Thursday (Nov. 16) that it will not shut down the Arecibo Observatory. This decision comes after more than a decade of discussions about the future of the 54-year-old observatory.

However, this good news comes with one drawback: The NSF still plans to withdraw much of the funding it gives to the observatory, reducing its annual contribution from $8.2 million to $2 million over the next five years, the journal Nature reports. But instead of leaving the observatory high and dry, the NSF is working to secure new partnerships with other institutions that can take over the burden of funding and managing the facility. [Arecibo Observatory: Puerto Rico’s Giant Radio Telescope in Photos] 

“This is very good news for the Arecibo Observatory and a huge win for the scientific community in general,” Francisco Córdova, the observatory’s director, told Nature. “There is definitely a sense of relief in the air.”

The announcement brought a much-needed sigh of relief to the people who operate the observatory as well as many other members of the local community who found shelter and solace at the facility after losing their homes in Hurricane Maria.

While the Arecibo Observatory fared pretty well during hurricane compared to much of the rest of the island, it did sustain some minor damages. With the NSF already working on plans to reduce funding and potentially close the observatory, costly damages could have been the last straw. However, the damage turned out to be minimal. The NSF estimates that repairs should cost somewhere between $4 million and $8 million. 

“NSF remains deeply concerned about the impacts from recent hurricanes on Arecibo Observatory staff, the facility and all citizens of Puerto Rico,” NSF officials said in a statement, adding that the decision “arrives at a challenging time, but is necessary for the agency to secure a future for the observatory. It will allow negotiations to begin with potential collaborators who may take over management and operations as NSF funding for the observatory is reduced. 

“We were quite surprised by how little damage there was,” John Kelly, an investigator with SRI International, which helps to operate the observatory, told Space.com. “The reflector itself sustained minor damage when a couple of minor feed antennas broke and fell into the dish, damaging 15 or 20 of the panels. There are thousands of panels that make up that reflector, and only about 15 or 20 have been damaged. And they’re replaceable … I don’t think the damage is anywhere near what would be considered a justifiable reason for decommissioning the facility at this point,” Kelly said.

In addition to the NSF, SRI International and other research institutions, the Arecibo Observatory also receives funding from NASA to look for near-Earth asteroids that could pose a danger to the planet. Astronomers also use the facility to look for potentially habitable exoplanets and signs of extraterrestrial intelligence.

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Scientist Send Message To Alien Planet To Contact E.T.

November 24, 2017 by  
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If there are any intelligent aliens in the GJ 273 system, they can expect to hear from us about a dozen years from now.

Last month, scientists and artists beamed a message to GJ 273, a red dwarf also known as Luyten’s star that lies 12.36 light-years from Earth, project team members revealed today (Nov. 16). Luyten’s star hosts two known planets, one of which, GJ 273b, may be capable of supporting life as we know it.

Though the message was designed to provoke a response from the hypothetical denizens of GJ 273b, the main goal in sending the communication involved laying a foundation for the future, said team member Douglas Vakoch, president of METI (Messaging Extraterrestrial Intelligence) International, a San Francisco-based nonprofit.

“It is a prototype for what I think we would most likely need to do 100 times, or 1,000 times, or 1 million times,” Vakoch told Space.com. “To me, the big success of the project will come if, 25 years from now, there’s someone who remembers to look [for a response]. If we could accomplish that, that would be a radical shift of perspective.”

Indeed, humanity’s demonstrable penchant for short-term thinking has prompted some skepticism within the SETI (search for extraterrestrial intelligence) community about METI as a viable strategy, Vakoch said. (METI is also known as “active SETI.” “Traditional” SETI involves listening and looking for signals that could be from E.T.)

METI is controversial for another reason as well. Some critics — most famously, physicist Stephen Hawking — have suggested that the strategy could betray our existence to super-advanced hostile or resource-hungry aliens, with potentially dire consequences for humanity and the rest of the planet. will end in 14 seconds.

But beaming a message to Luyten’s star doesn’t increase the risk of an alien attack, Vakoch said. 

“It’s really hard to imagine a scenario in which a civilization around Luyten’s star could have the capacity to come to Earth and threaten us, and yet they’re not able to pick up our leakage radiation,” he said, referring to the TV and radio signals that have been slipping out into the cosmos from Earth for more than half a century.

The Luyten’s star project, known as “Sónar Calling GJ 273b,” is a collaboration involving METI International; the Institute of Space Studies of Catalonia in Spain; and Sónar, a music, creativity and technology festival in Barcelona, Spain.

“Doing it in partnership with the Sónar festival is a way that we can respect the necessity of incorporating a scientific perspective but also to recognize that doesn’t capture the fullness of the human spirit,” Vakoch said.

Team members crafted a message that includes a scientific and mathematical “tutorial,” as well as 33 short musical compositions by artists in the Sónar community. The team beamed this message out in binary code at two different radio frequencies on Oct. 16, Oct. 17 and Oct. 18, using the 105-foot-wide (32 meters) European Incoherent Scatter Scientific Association (EISCAT) radio antenna in Tromsø, Norway.

Luyten’s star was chosen primarily for its proximity to Earth, which could theoretically lead to a relatively rapid response. The red dwarf is the nearest star visible from the Northern Hemisphere that’s known to host a potentially habitable planet, Vakoch said. (That planet, by the way is a “super-Earth” about three times more massive than our own.”

The ease of conversation has not always factored in to METI campaigns. In 1974, for example, Puerto Rico’s Arecibo Observatory beamed a message devised by Frank Drake, Carl Sagan and other researchers toward the globular cluster M13, which lies 25,000 light-years away from Earth. (This “Arecibo message” began its long space journey 43 years ago today, in fact.)

The October transmissions represented the first phase of “Sónar Calling GJ 273b.” The group also plans to send an “expanded tutorial” to Luyten’s star in April 2018 at several different radio frequencies, turning the EISCAT antenna into something like a musical instrument, team members said.

Courtesy-Space

Astronomers Find New Alien Planet Suitable For Life

November 21, 2017 by  
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A newfound exoplanet may be one of the best bets to host alien life ever discovered — and it’s right in Earth’s backyard, cosmically speaking.

Astronomers have spotted a roughly Earth-mass world circling the small, dim star Ross 128, which lies just 11 light-years from the sun. The planet, known as Ross 128b, may have surface temperatures amenable to life as we know it, the researchers announced in a new study that will appear in the journal Astronomy & Astrophysics.

Ross 128b is 2.6 times more distant from Earth than Proxima b, the potentially habitable planet found in the nearest solar system to the sun. But Proxima b’s parent star, Proxima Centauri, blasts out a lot of powerful flares, potentially bathing that planet in enough radiation to stunt the emergence and evolution of life, scientists have said. [10 Exoplanets That Could Host Alien Life]

Radiation is likely much less of an issue for Ross 128b, because its parent star is not an active flarer, said discovery team leader Xavier Bonfils, of the Institute of Planetology and Astrophysics of Grenoble and the University of Grenoble Alpes in France.

“This is the closest Earth-mass planet potentially in the habitable zone that orbits a quiet star,” Bonfils told Space.com

Bonfils and his colleagues found Ross 128b using the High Accuracy Radial velocity Planet Searcher (HARPS), an instrument at the European Southern Observatory’s La Silla Observatory in Chile.

As its name suggests, HARPS employs the “radial velocity” method, noticing the wobbles in a star’s movement induced by the gravitational tugs of orbiting planets. (NASA’s prolific Kepler space telescope, by contrast, uses the “transit” technique, spotting tiny brightness dips caused when a planet crosses its host star’s face from the spacecraft’s perspective.)

The HARPS observations allowed Bonfils and his team to determine that Ross 128b has a minimum mass 1.35 times that of Earth, and that the planet orbits its host star once every 9.9 Earth days.

Such a tight orbit would render Ross 128b uninhabitable in our own solar system. But Ross 128 is much cooler than the sun, so the newfound world is likely temperate, the researchers said. Determining whether  the planet is actually capable of supporting life as we know it, however, would require a better understanding of its atmosphere, Bonfils said.

“Ross 128b receives 1.38 times [more] irradiation than Earth from our sun,” he said. “Some models made by theorists say that a wet Earth-size planet with such irradiation would form high-altitude clouds. Those clouds would reflect back to space a large fraction of the incident light, hence preventing too much greenhouse heating. With those clouds, the surface would remain cool enough to allow liquid water at the surface. Not all models agree, though, and others predict this new planet is rather like Venus.

Though both Ross 128 and Proxima Centauri are red dwarfs — the most common type of star in the Milky Way galaxy — they are very different objects.

“Proxima Centauri is particularly active, with frequent, powerful flares that may sterilize (if not strip out) its atmosphere,” Bonfils said. “Ross 128 is one of the quietest stars of our sample and, although it is a little further away from us (2.6x), it makes for an excellent alternative target.”

And the star may indeed be targeted in the not-too-distant-future — by giant ground-based instruments such as the European Extremely Large Telescope, the Giant Magellan Telescope and the Thirty Meter Telescope, all of which are scheduled to be up and running by the mid-2020s.

Such megascopes should be able to resolve Ross 128b and even search its atmosphere for oxygen, methane and other possible signs of life, Bonfils said. (NASA’s $8.9 billion James Webb Space Telescope, which is scheduled to launch in early 2019, probably won’t be able to perform such a biosignature search, the researchers said in their discovery paper. If Ross 128b transited its host star from Webb’s perspective, it would likely be a different story, they added.)

Earlier this year, by the way, radio astronomers detected a strange signal that seemed to be emanating from Ross 128. But further investigation revealed that the signal most likely came from an Earth-orbiting satellite, not an alien civilization.

Courtesy-Space

Does Proxima b Have Neighbors

November 10, 2017 by  
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The nearest alien planet to Earth may not be an only child.

Astronomers have spotted a dusty ring around the nearby star Proxima Centauri, hinting at the existence of other planets in addition to the famous Proxima b, a new study reports.

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“This result suggests that Proxima Centauri may have a multiple-planet system with a rich history of interactions that resulted in the formation of a dust belt,” study lead author Guillem Anglada, an astronomer at the Instituto de Astrofisica de Andalucia in Spain, said in a statement. “Further study may also provide information that might point to the locations of as-yet unidentified additional planets.” [Proxima b: Closest Earth-Like Planet Discovery in Pictures]

Proxima Centauri is a red dwarf that lies about 4.2 light-years from Earth, in the southern constellation of Centaurus (The Centaur). In 2016, researchers spotted Proxima b, an apparently Earth-size world orbiting the star in what seems to be the habitable zone, the region where liquid water could exist on the surface. The star itself is about the same age as the sun. (Coincidentally, the team that discovered Proxima b was led by Guillem Anglada-Escudé of Queen Mary University of London, a part of Anglada’s team but no relation to the author of the new research.)

Anglada and his colleagues studied Proxima Centauri using the Atacama Large millimeter/submillimeter Array (ALMA), a network of telescopes in Chile. The researchers discovered a belt of dusty material containing about 1 percent the mass of Earth. The belt — which lies a few hundred million kilometers from the star, far beyond Proxima b’s orbit — has a temperature of about minus 328 degrees Fahrenheit (minus 230 degrees Celsius), roughly the same temperature of the solar system’s Kuiper Belt, researchers said.

The dusty material might range in size from grains of only a few millimeters to asteroid-like bodies several kilometers across, study team members said. Dust belts like this are thought to be the remains of material that didn’t manage to clump together to form planets, they added.

ALMA also spotted signs of a possible second dust ring, about 10 times farther from the star than the other one, though this feature awaits confirmation. If the outer ring does indeed exist, its material would be very cold, lying so far from a star that is much smaller and dimmer than the sun.

The faint outer belt could prove useful to astronomers: Studying its shape could yield a better understanding of Proxima b’s mass, which is not known very well at the moment, the researchers said.  

And then there’s the exploration angle. The $100 million Breakthrough Starshot project aims to send sail-equipped, laser-driven microprobes zooming past Proxima b in the not-too-distant-future, and mapping out the system’s dust environment could be key to the success of such a mission, study team members said.

“These first results show that ALMA can detect dust structures orbiting around Proxima. Further observations will give us a more detailed description of Proxima’s planetary system,” study co-author Pedro Amado, also from the Instituto de Astrofiscia de Andaluicia, said in the same statement. “What we are seeing now is just the appetizer compared to what is coming!”

The new study has been accepted for publication in Astrophysical Journal Letters.

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Planet Star Duo Puzzles Astronomers

November 3, 2017 by  
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A giant planet has been found orbiting an ultracool dwarf star — the largest planet compared to its star ever found — leaving scientists baffled at how the duo could have formed.

The planet NGTS-1b is situated 600 light-years from our solar system, according to a statement from the University of Warwick, and it is a gas giant about the size of Jupiter. Its star, on the other hand, is just half the mass and radius of the sun. The planet orbits its star at 3 percent the distance from the Earth to the sun, and it whips around a full orbit every 2.6 Earth days.

An international collaboration of researchers found the planet using the Next-Generation Transit Survey, an array of 12 telescopes at the Paranal Observatory in northern Chile that searches for a telltale dimming in distant stars that would indicate planets passing by. [7 Ways to Discover Alien Planets]

“The discovery of NGTS-1b was a complete surprise to us — such massive planets were not thought to exist around such small stars,” Daniel Bayliss, lead author on the new work and a researcher at University of Warwick in the United Kingdom, said in the statement. “This is the first exoplanet we have found with our new NGTS facility, and we are already challenging the received wisdom of how planets form.”

The system’s star is a small, dim M-dwarf, which is the most common type of star in the sky. Red dwarfs burn their fuel much more slowly than sun-like stars, so they can have lifetimes of trillions of years. According to the new work, this is the third time a gas giant has been seen orbiting an M-dwarf — but this planet is by far the largest.

While it can be tricky enough just to spot planets orbiting M-dwarfs, researchers are much more used to seeing M-dwarfs orbited by rocky planets, according to a statement from the Royal Astronomical Society. In February, for instance, researchers found seven rocky planets orbiting the small, dim TRAPPIST-1. NGTS-1 is larger than TRAPPIST-1, but researchers are still unsure how the star could have gathered enough material to build a large gas giant during the system’s formation, they said in the statement.

To find NGTS-1b, the Next-Generation Transit Survey monitored certain spots in the sky for months with red-sensitive cameras to catch any changes in brightness to stars in its field of view, according to the statement from the University of Warwick. Researchers saw the particular M-dwarf dipping in brightness every 2.6 days, suggesting it had a planetary companion. Then, they confirmed the planet’s gargantuan size by measuring its radial velocity — how much the star “wobbles” during each orbit from its companion’s gravitational pull. 

“NGTS-1b was difficult to find, despite being a monster of a planet, because its parent star is small and faint,” Bayliss said. “Small stars are actually the most common in the universe, so it is possible that there are many of these giant planets waiting to be found.”

“Our challenge is to now find out how common these types of planets are in the galaxy, and with the new NGTS facility, we are well-placed to do just that,” he added.

The new work, currently available on arXiv.org, has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

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Is Another Mission To Pluto Being Planned

October 31, 2017 by  
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A grassroots movement seeks to build momentum for a second NASA mission to the outer solar system, a generation after a similar effort helped give rise to the first one.

That first mission, of course, was New Horizons, which in July 2015 performed the first-ever flyby of Pluto and is currently cruising toward a January 2019 close encounter with a small object known as 2014 MU69.

New Horizons got its start with letter-writing campaigns in the late 1980s, and the new project hopes to duplicate that success, said campaign co-leader Kelsi Singer, a New Horizons team member who’s based at the Southwest Research Institute (SwRI) in Boulder, Colorado.   

Nearly three dozen scientists have drafted letters in support of a potential return mission to Pluto or to another destination in the Kuiper Belt, the ring of icy bodies beyond Neptune’s orbit, Singer told Space.com.Next Up

These letters have been sent to NASA planetary science chief Jim Green, as well as to the chairs of several committees that advise the agency, she added.

“We need the community to realize that people are interested,” Singer said. “We need the community to realize that there are important, unmet goals. And we need the community to realize that this should have a spot somewhere in the Decadal Survey.”

That would be the Planetary Science Decadal Survey, a report published by the National Academy of Sciences that lays out the nation’s top exploration priorities for the coming decade.

“This is the way it normally works,” said New Horizons principal investigator Alan Stern, who’s also based at SwRI.

“First it bubbles up in the community and then, when there’s enough action, the agency starts to get behind it,” Stern, who has been the driving force behind New Horizons since the very beginning, told Space.com. “Then it lets the Decadal Survey sort things out.”

Stern contributed a letter to the new campaign, and he has voiced support for a dedicated Pluto orbiter. Singer would also be happy if NASA went back to the dwarf planet.

“Pluto just has so much going on,” she said.

But there are other exciting options available as well, Singer said. For example, NASA could do a flyby of a different faraway dwarf planet — Eris, perhaps — to get a better idea of the variety and diversity of these intriguing worlds.

Or the agency could target Kuiper Belt objects (KBOs) that have diameters of a few hundred kilometers or so, she added. New Horizons has flown by one “big” KBO (Pluto) and will soon see a small one — 2014 MU69 is just 20 miles (32 km) or so across — but there are no plans at the moment to study anything of an intermediate size up close.

The last Decadal Survey was put out in 2011, and it covers the years 2013 to 2022. The next one is due out in five years, and it will help map out NASA’s plans for the 2020s and early 2030s. So Singer knows she and her colleagues must be patient, even if their letter-writing campaign ultimately bears fruit.

“I would say 25 years is the longest I think about,” she said, referring to how long it may be before another Kuiper Belt mission gets to its destination. “And I hope it may be more like 15 years.”

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Does Proxima Centauri b Have A Shiny Green Tint

October 17, 2017 by  
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A world orbiting the sun’s closest stellar neighbor may have a shiny green tint to it — and not necessarily because it’s covered in leafy plants. 

Researchers have found a way to characterize potential auroras on the nearby exoplanet Proxima Centauri b and found that, if the planet sports oxygen in its atmosphere, the auroras may give the atmosphere a greenish cast. 

“The northern and southern lights [on Proxima Centauri b] would be at least 100 times brighter than on Earth,” Rodrigo Luger, a postdoctoral student at the University of Washington, who led the study of how the planet’s auroras could be spotted from Earth, told Space.com by email. Luger said the auroras might be so bright as to be visible with very powerful telescopes.

The active star Proxima Centauri lies only 4.2 light-years from the solar system. A small world orbits in the star’s habitable zone, the region where liquid water could survive on the surface. Its radius remains a mystery. However, scientists know it is about 1.3 times as massive as the Earth, which its initial discovers said suggests a rocky planet. 

Proxima Centauri is a small star, dimmer than Earth’s sun, so its habitable zone is closer to the star than the habitable zone of the sun. As a result, Proxima Centauri b is 20 times closer to its star than Earth is to the sun, and completes an orbit every 11.2 Earth-days. The red dwarf star is more active than Earth’s sun, firing off far more frequent flares that may douse the planet in radiation that could be harmful for potential life. 

Those same flares may help scientists better understand the planet. If Proxima Centauri b has a magnetic field, it may capture the charged particles in the flares and funnel them toward the poles, creating brilliant auroral displays. 

Observing the auroras can help researchers characterize the planet’s atmosphere. On Earth, the different color glow of the northern and southern lights corresponds to reactions with different molecules in the atmosphere. According to Luger, who presented the results at the Astrobiology Science Conference in Mesa, Arizona, in April, if Proxima Centauri b is a terrestrial world with an Earth-like atmosphere and a magnetic field, the green light of the oxygen auroras would grow 100 times stronger than on Earth.

Because of the potential for green light, the researchers dubbed such a world “the pale green dot,” a nod to Carl Sagan’s categorization of Earth as a pale blue dot.

Periods of intense stellar activity could make the auroras even brighter. While coronal mass ejections and flares have the strongest impact on generating auroras, Luger said, they aren’t really predictable in advance.

“But the sun certainly has periodic activity cycles, so if we understand those of Proxima Centauri, we might be able to use that to our advantage,” he said.

He went on to say that the extreme activity of the star may make such knowledge unnecessary — astronomers could simply count on a high likelihood that the star would flare and cause the auroras to brighten.

While several studies have described searches for auroras on gas giant exoplanets that orbit close to their parent stars, none have been spotted on worlds beyond the solar system. But Luger remains confident.

“Proxima Centauri b is optimal for auroral detection,” he said.

He gave several reasons that auroras may be soon spotted on Proxima Centauri b. The planet is nearby — it’s the closest known exoplanet to Earth — making it easier for instruments to collect detailed observations. The extreme magnetic activity of the star, coupled with the planet’s close orbit, means Proxima Centauri b is bombarded with solar particles far more vigorously than Earth. At the same time, the star is faint, so a glowing green planet would show up more easily than it would around a sun-like star. Finally, the short orbit means that the world moves around its sun at a rapid clip; when a light source is moving toward or away from an observer, this motion can be observed through a phenomenon called redshift, or Doppler shift. Luger said the Doppler shift of the auroras’ light waves would be significantly larger than they would be on their own, making lines that would otherwise be hard to see more visible. That would make it easier to identify any oxygen in the atmosphere.

Unfortunately, this “pale green dot” won’t be spotted with current telescopes. NASA’s upcoming powerhouse telescope ― the James Webb Space Telescope ― will hunt for infrared light, so Luger said it won’t be able to detect the green oxygen aurora, which is in the visible light range.

“Our best bet for detection is the [Thirty-Meter Telescope] or similar next-generation extremely large telescopes,” he said.

The Thirty-Meter Telescope (TMT) — so-named because its primary mirror would be 30 meters (98 feet) wide — began construction on Hawaii’s Mauna Kea peak before it was halted in 2015 after protests over the sacred nature of the land. The project remains at a halt today, though some astronomers have lauded the benefits of moving the telescope to Spain’s Canary Islands.

But even TMT would take some time to identify the signature of oxygen from the auroras, with Luger estimating “tens of hours” of observation. The same is true for the Large UV/Opitcal/Infrared Survey (LUVOIR), a proposed design for a telescope with a primary mirror between 9 and 15 meters (30 and 50 feet). With telescope time extremely competitive, it could be hard to study the system so extensively.

In order to produce auroras, a planet must have a magnetic field. Out of the four terrestrial planets in Earth’s solar system, only two have a worldwide field — Earth and Mercury. Mars has a patchy field, and Venus has none. If Proxima Centauri b is similarly lacking, it might not produce auroras.

However, the planet may get a brightness boost from airglow, the faint emission of light from the atmosphere that keeps nighttime on Earth from ever being completely dark.

“The planet is likely also to have strong airglow, which is planetwide,” Luger said. “Airglow is not generated by magnetic fields, and is typically weaker than aurorae, so we did not calculate it. But it should be quite strong on Proxima Centauri b, and could cause the entire planet to glow green.”

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Astronomers Discover Water Mystery On Mars

October 9, 2017 by  
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A new examination of old data suggests that there might be ice hiding in the Martian equator, even though scientists previously thought that the substance couldn’t exist there.

Scientists uncovered an unexpected amount of hydrogen when looking at older data from NASA’s Mars Odyssey spacecraft dating back to between 2002 and 2009. At higher latitudes, hydrogen generally indicates buried water ice, but this was not believed possible at the equator, according to a statement from NASA.

If there is indeed water there, this would help with a future human mission to Mars, because it could mean the astronauts wouldn’t need to bring the substance with them for drinking, cooling equipment or watering plants, researchers said in the statement. Instead, the astronauts could live off the land to an extent, reducing the number of resources that need to be trucked (at higher cost) from Earth

Mars Odyssey’s first major discovery, in 2002, was also linked to water; the spacecraft found buried hydrogen at high latitudes, and the 2008 landing of the Phoenix Mars lander confirmed that there was water ice. However, at lower latitudes, measurements of hydrogen were explained as hydrated minerals (which other spacecraft have also observed). Researchers didn’t think water ice was thermodynamically stable in those areas.

For this new study, the researchers analyzed data collected using Mars Odyssey’s neutron spectrometer. The instrument is not designed to directly detect water, but by measuring neutrons, it can detect signatures of hydrogen, which can mark the presence of water or other hydrogen-bearing substances. 

The science team reduced the blurring or “noise” in Odyssey’s data using image-reconstruction techniques based on those used for other spacecraft and for medicine, according to the statement. This improved the spatial resolution of the data to 180 miles (290 kilometers), twice the previous resolution of 320 miles (520 km).

“It was as if we’d cut the spacecraft’s orbital altitude in half, and it gave us a much better view of what’s happening on the surface,” Jack Wilson, the study’s principal investigator and a postdoctoral researcher at the Johns Hopkins University Applied Physics Laboratory.

Their work focused on equatorial areas, particularly in zones around the Medusae Fossae formation, an area that includes material that is easy to erode. Previous observations from NASA’s Mars Reconnaissance Orbiter and the European Space Agency’s Mars Express orbiter suggested there might be volcanic deposits or water ice just below the surface. Scientists, however, were skeptical that it was water ice, because “if the detected hydrogen were buried ice within the top meter [3.3 feet] of the surface, there would be more than would fit into pore space in soil,” Wilson said.

The study’s scientists emphasized that more evidence is needed to conclude that the signature indeed comes from water ice. They’re not too sure how the water was preserved, they said; perhaps ice and dust flowing from the poles moved through the atmosphere when Mars had a steeper axis tilt than today. However, it’s been at least hundreds of thousands of years since those conditions existed, and the water ice deposited back then shouldn’t be around anymore, the researchers said. (This would be true even if, somehow, dust or a crust at the surface trapped the humidity underground, the scientists added.)

“Perhaps the signature could be explained in terms of extensive deposits of hydrated salts, but how these hydrated salts came to be in the formation is also difficult to explain,” Wilson said. “So, for now, the signature remains a mystery worthy of further study, and Mars continues to surprise us.”

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Astronomers Find Carbon Star With Red Glowing Bubble

September 28, 2017 by  
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Gorgeous new imagery shows the enormous, glowing bubble that a strange, dying red star has blown around itself.

The huge star, known as U Antliae, lies about 900 light-years from Earth, in the southern constellation Antlia (the Air Pump). U Antliae has burned all the hydrogen and helium in its core and has therefore moved on to the “asymptotic giant branch” (AGB), the last major step in the life cycle of a sun-like star before it becomes superdense white dwarf. 

AdvertisementA few millennia ago, U Antliae erupted in a spasm of activity that generated a big bubble, a surprisingly thin structure that astronomers have now studied using the European Southern Observatory’s Atacama Large Millimeter/submillimeter Array (ALMA), a network of radio telescopes in northern Chile.

“Around 2,700 years ago, U Antliae went through a short period of rapid mass loss,” ESO officials wrote in a statement. “During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy gas clouds known as filamentary substructures.”

ALMA captured the bubble in multiple wavelengths of light, producing a 3D “data cube” that researchers have mined in detail. For example, the imagery shows gases in the bubble moving toward or away from the observer at different speeds, ESO officials said.

This image was created from ALMA data on the red carbon star U Antliae and its surrounding shell of material. The colors show the motion of the glowing material in the shell along the line of sight to the Earth. Blue material lies between us and the central star, and is moving toward us. Red material around the edge is moving away from the star, but not toward Earth. (For clarity, this view does not include the material on the far side of the star, which is receding from us in a symmetrical manner.)

Analyzing such stellar bubbles could help astronomers better understand the evolution of stars and galaxies, ESO officials added.

“Shells such as the one around U Antliae show a rich variety of chemical compounds based on carbon and other elements,” the officials wrote in the same statement. “They also help to recycle matter and contribute up to 70 percent of the dust between stars.”

The new ALMA imagery is part of a study, led by Franz Kerschbaum of the University of Vienna, that has been accepted for publication in the journal Astronomy & Astrophysics.

Courtesy-Space 

Does The Asteroid Belt Hold Key To The Building Blocks Of Planets

September 27, 2017 by  
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The asteroid belt may have started out empty, later becoming a “cosmic refugee camp” taking on leftovers of planetary formation from across the solar system, a new study finds.

The main asteroid belt, located between the orbits of Mars and Jupiter, makes up 0.05 percent the mass of Earth. The asteroids there can range greatly in mass, with the four largest ones — Ceres, Vesta, Pallas and Hygiea — holding more than half the belt’s mass.

To explain the dramatic range of sizes in the asteroid belt, previous models suggested that the primordial asteroid belt originally possessed a mass equal to at least that of Earth, and that its members had less disparity in mass. The gravitational pulls of the planets later helped whittle down this primordial belt, depleting asteroids of certain sizes more than others.  

However, these prior models of asteroid formation raised a question: how the belt could have lost more than 99.9 percent of its mass without losing all of it, said study lead author Sean Raymond, an astronomer at the University of Bordeaux in France.

“Our approach is the opposite. We asked the question, ‘Could the asteroid belt have been born empty?’,” Raymond told Space.com. “The answer is yes, effortlessly.”

The scientists developed computer models of an empty primordial asteroid belt to see whether leftovers from planetary formation could explain the belt’s current composition. The inner belt is dominated by dry S-type, or silicaceous, asteroids, which appear to be made of silicate materials and nickel iron and account for about 17 percent of known asteroids. The outer belt is dominated by water-rich C-type, or carbonaceous, asteroids, which consist of clay and stony silicate rocks and make up more than 75 percent of known asteroids.

The researchers found that an empty primordial asteroid belt could explain the mass and compositions of the current members of the asteroid belt. This model suggests that this zone between Mars and Jupiter is a repository of planetary leftovers, “a refugee camp housing objects that were kicked out of their homes and left to brave interplanetary space, finally settling onto stable orbits in the asteroid belt,” Raymond told Space.com. 

In this new model, the inner belt consists largely of rocky leftovers from the formation of the terrestrial planets — Earth, Mars, Venus and Mercury. In contrast, the outer belt is made up of remnants of the formation of the gas giant planets, such as Jupiter and Saturn.

“In terms of composition, Jupiter and Saturn grew in a region that was much colder than where the rocky planets grew,” Raymond said. “Being colder, their cores could incorporate ice and other volatiles. The C-types are about 10 percent water, whereas the S-types are much drier, having started off in the much hotter terrestrial planet zone.”

These findings suggest that the asteroid belt “is a treasure trove — it must contain relics of the building blocks of all the planets,” Raymond said. “There must be pieces of terrestrial building blocks out in the asteroid belt, as well as leftovers from building the giant planets’ cores.”

Future research can further test how well the various models of asteroid-belt formation match reality. Raymond hopes the team’s new concept “will help keep people’s minds open to potentially drastically different origins stories for the solar system, and for extra-solar planets, too.”

Raymond and his colleague Andre Izidoro at the University of Bordeaux detailed their findings online Sept. 13 in the journal Science Advances.

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Astronomers Ponder The Role Of Physics In Life

September 25, 2017 by  
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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.

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