Thomas Hawk posted a photo:
CNN reports:
The popular theory that comets were crucial in kick-starting life on Earth billions of years ago may not hold up, according to new computer simulations that counter decades of scientific thinking. The finding suggests the fragile organic molecules supposedly carried by the icy objects would have been destroyed on impact, upending an established origin of life theory that dates back to at least 1961 [with earlier versions postulated in 1908]...
Early in its history — over 4 billion years ago — Earth may have experienced a period of heavy bombardment from more than 100,000 comets larger than 100 meters (328 feet), according to the new study, published Wednesday in the journal Scientific Reports. Those impacts, however, were mostly too heavy for life-starting molecules to withstand. The team used the latest models of comet formation and evolution to simulate this early planetary period 100,000 times. "Given what we know about surface environments on the early Earth, on average, our simulations found that there were no successful impacts," said lead study author Richard Anslow, who conducted the research while completing his doctorate at the Institute of Astronomy of the University of Cambridge in the United Kingdom... "The typical velocities of these comets when they impact the Earth meant that actually very few, if any, would have been able to deliver intact organic molecules, so comets actually don't seem to be as useful for prebiotic chemistry as was previously thought," Anslow said.
More precisely, 54% of the simulations showed no impact at all, while the remaining 46% had at least one and a "tiny minority" returned up to three collisions, Anslow said. "We can't rule out confidently that there was never a successful impact — there could have been one of these fluke impacts." However, such flukes had to occur in a "perfect location" that already met several important conditions, including the presence of liquid water and other chemicals needed to support life. That combination makes the overall process unlikely, he added.
The article notes his argument that even if a successful impact occurred, it's unlikely an important chemical like hydrogen cyanide (HCN) could survive the impact, and would've dissolved in an ocean impact. Plus, "many other precursor molecules are also needed, such as compounds that contain phosphorus and sulfur, but these are not routinely found in comets, Anslow said."
An alternative cosmic source of organic material could have been asteroids, which typically struck Earth more slowly and in greater numbers. Anslow pointed to recent findings on samples from asteroids Bennu and Ryugu, which contain the majority of protein-building amino acids. The recent study also raises another intriguing possibility: While Earth may not have had the ideal conditions to foster HCN from comet impacts, ancient Mars might have been better suited. "Because Mars is much smaller than Earth and further away from the sun, the typical impact velocity of comets is much lower, so while these impacts on Earth were destroying most of the HCN, this wasn't the case so much for Mars," Anslow said. This idea could add another dimension to the long-standing question of whether the red planet once supported life.
While the authors closely analyzed how HCN could have survived comet impact, the chemical may have undergone reactions before the icy bodies entered Earth's atmosphere, said Queenie Chan, an associate professor of Earth sciences at Royal Holloway University of London, who was not involved with the study. This process could have created biologically important compounds, such as those protein building blocks, that are less volatile and more likely to survive.
The popular theory that comets were crucial in kick-starting life on Earth billions of years ago may not hold up, according to new computer simulations that counter decades of scientific thinking. The finding suggests the fragile organic molecules supposedly carried by the icy objects would have been destroyed on impact, upending an established origin of life theory that dates back to at least 1961 [with earlier versions postulated in 1908]...
Early in its history — over 4 billion years ago — Earth may have experienced a period of heavy bombardment from more than 100,000 comets larger than 100 meters (328 feet), according to the new study, published Wednesday in the journal Scientific Reports. Those impacts, however, were mostly too heavy for life-starting molecules to withstand. The team used the latest models of comet formation and evolution to simulate this early planetary period 100,000 times. "Given what we know about surface environments on the early Earth, on average, our simulations found that there were no successful impacts," said lead study author Richard Anslow, who conducted the research while completing his doctorate at the Institute of Astronomy of the University of Cambridge in the United Kingdom... "The typical velocities of these comets when they impact the Earth meant that actually very few, if any, would have been able to deliver intact organic molecules, so comets actually don't seem to be as useful for prebiotic chemistry as was previously thought," Anslow said.
More precisely, 54% of the simulations showed no impact at all, while the remaining 46% had at least one and a "tiny minority" returned up to three collisions, Anslow said. "We can't rule out confidently that there was never a successful impact — there could have been one of these fluke impacts." However, such flukes had to occur in a "perfect location" that already met several important conditions, including the presence of liquid water and other chemicals needed to support life. That combination makes the overall process unlikely, he added.
The article notes his argument that even if a successful impact occurred, it's unlikely an important chemical like hydrogen cyanide (HCN) could survive the impact, and would've dissolved in an ocean impact. Plus, "many other precursor molecules are also needed, such as compounds that contain phosphorus and sulfur, but these are not routinely found in comets, Anslow said."
An alternative cosmic source of organic material could have been asteroids, which typically struck Earth more slowly and in greater numbers. Anslow pointed to recent findings on samples from asteroids Bennu and Ryugu, which contain the majority of protein-building amino acids. The recent study also raises another intriguing possibility: While Earth may not have had the ideal conditions to foster HCN from comet impacts, ancient Mars might have been better suited. "Because Mars is much smaller than Earth and further away from the sun, the typical impact velocity of comets is much lower, so while these impacts on Earth were destroying most of the HCN, this wasn't the case so much for Mars," Anslow said. This idea could add another dimension to the long-standing question of whether the red planet once supported life.
While the authors closely analyzed how HCN could have survived comet impact, the chemical may have undergone reactions before the icy bodies entered Earth's atmosphere, said Queenie Chan, an associate professor of Earth sciences at Royal Holloway University of London, who was not involved with the study. This process could have created biologically important compounds, such as those protein building blocks, that are less volatile and more likely to survive.
Read more of this story at Slashdot.
George Russell second on grid after qualifying
Antonelli well placed as he nears title confirmation
Even as Formula One’s young gun Kimi Antonelli remains on course to claim his first world championship on Sunday it was the veteran, seven-time champion Lewis Hamilton who gave a salutary reminder that there is very much fight left in the old dog yet as he claimed a spectacular pole position for the Mexico City Grand Prix.
Hamilton delivered a superb lap for Ferrari to secure his first pole for the team and just beat Mercedes’ George Russell into second. World champion in waiting Antonelli was in fourth place but remains in position to close out the title on Sunday, although Hamilton and Russell, who must win the race to have any hope of keeping the fight alive, have at least locked out the front row.
Continue reading...Prime minister says shake-up is vital to restore tribunal crippled by years of political disputes
Poland’s prime minister, Donald Tusk, has vowed to see through a contested overhaul of the country’s constitutional court, declaring that “in certain matters, there can be no compromise”.
In a prime-time television address on Saturday night, Tusk was defiant, despite overnight protests that saw riot police drafted to protect the court’s building, saying the shake-up was vital to restore a tribunal crippled by years of political disputes.
Continue reading...
Beste lezer van GeenStijl. Het is 1 november en op 1 november gaat GeenStijl ieder jaar op zwart. Nou ja, op zwart... Wee wee wee punt Geen Stijl punt en el werkt vandaag niet zoals alle andere dagen, want waar je ook klikt, je komt de hele tijd op deze tekst uit. Dat is omdat wij vieren dat wij exact acht jaar onafhankelijk zijn. Dat betekent dat wij kunnen schrijven wat we willen en doen wat we willen, zoals vandaag AAN JOU VRAGEN OM ONZE HELD TE WORDEN ALS GEENSTIJL PREMIUM LID EN ERVOOR TE ZORGEN DAT GEENSTIJL NOG HEEL LANG VLIJMSCHERP, ONGEFILTERD EN ONAFHANKELIJK BLIJFT.
Het afgelopen jaar versloegen we het wereldgebeuren van Venezuela tot Iran en van Ceuta tot aan Frankrijk en bleven we in Nederland roeren waar het stinkt. Onze topics leverden meer Kamervragen op dan ooit en zorgden tot twee keer toe zelfs voor een roze Vragenuur in Den Haag: het ministerie van Onderwijs gooide een aan GeenStijl gelekte taalgids in de prullenbak, een paar maanden later moest zelfs de D66-staatssecretaris van Justitie toegeven dat het niet bepaald wenselijk is dat de Syrische Mohammed K. met 114 politieregistraties op zijn naam zijn familie binnenkort over laat komen naar Nederland. En terwijl de systeemmedia na het aftreden van Dick Schoof opgelucht ademhaalden en hun kritische blik weer voor vier jaar in de ijskast legden, lieten wij ministers Boekholt-O'Sullivan en Letschert met hun mond vol tanden schutteren voor de roze plopkap van Tom Staal. Maar wij kunnen alleen maar blijven doen wat wij doen met jouw steun.Â
Want wij hebben geen overheidsmiljarden, geen Belgische miljoenen, en ook geen Belgische overheidsmiljoenen trouwens, achter de hand om algoritmisch goedgekeurde brand safety deugkots door je scherm te rammen. Wij zijn gewoon Spartacus, Mosterd, Ronaldo, Zorro, Dorbeck en Zilthaeck die ieder uur iets tikken waar we zelf om moeten lachen, huilen of onbedaarlijk woest grommen, en jullie gelukkig heel vaak ook. Dat is waarom wij iedere dag onze laptop weer aanslingeren en dat is waarom je nergens anders zo'n mix van keiharde satire, vlijmscherpe kritiek en ongefilterd nieuws tegenkomt als op GeenStijl.
En hee. Sinds een tijdje geven we je er ook nog iets extra's voor terug. Onze GeenStijl Premium Podcast met Spartacus en Talitha Muusse is namelijk alleen volledig te beluisteren voor Premium Leden. Want hun steun is de reden dat GeenStijl nog altijd onafhankelijk kan blijven bestaan. En het fijne is: nog nooit hebben we zoveel Premium Leden gehad als nu. Maar als we echt onafhankelijk willen blijven, dan hebben we er nog veel meer nodig.
Zorg daarom dat GeenStijl nĂłg eens acht jaar vlijmscherp en ongefilterd blijft en WORD PREMIUM LID VAN GEENSTIJL.
Hiep hiep hoera
Ben je al lid en wil je ons een tof verjaarscadeau geven? DANKJEWEL!!!
Doneer hierFRANKFURT (ANP/DPA) - De Duitse politie heeft zaterdagavond een belangrijke winkelstraat in het centrum van Frankfurt afgezet na plunderingen. Relschoppers hadden etalages ingeslagen, winkels leeggeroofd en agenten aangevallen.
De Zeil, een van de drukste winkelstraten in Duitsland, werd afgesloten voor nieuwe bezoekers. De politie sommeerde omstanders het gebied te verlaten. Er ontstonden chaotische taferelen op de winkelstraat. Journalisten van persbureau dpa zagen hoe mensen winkels binnendrongen en sportschoenen en andere spullen stalen.
Ook een gespecialiseerde wapenwinkel werd aangevallen, wat leidde tot verschillende arrestaties. Agenten waren snel ter plaatse en namen twee wapens in beslag.
Waterkanon
De politie meldde ook aanvallen op agenten, onder meer met molotovcocktails.
Het geweld brak uit nadat de politie een jongerenprotest had beëindigd na herhaalde aanvallen op agenten met onder meer vuurwerk. De politie zette een waterkanon in om het protest te beëindigen.