Remembering the 343 New York City firefighters killed on 911

first_img Posted: September 6, 2019 Categories: Local San Diego News FacebookTwitter Remembering the 343 New York City firefighters killed on 9/11 September 6, 2019 Updated: 10:44 PMcenter_img KUSI Newsroom 00:00 00:00 spaceplay / pause qunload | stop ffullscreenshift + ←→slower / faster ↑↓volume mmute ←→seek  . seek to previous 12… 6 seek to 10%, 20% … 60% XColor SettingsAaAaAaAaTextBackgroundOpacity SettingsTextOpaqueSemi-TransparentBackgroundSemi-TransparentOpaqueTransparentFont SettingsSize||TypeSerif MonospaceSerifSans Serif MonospaceSans SerifCasualCursiveSmallCapsResetSave SettingsSAN DIEGO (KUSI) – In a few days, we will commemorate the anniversary of the 9/11 terror attacks.In Downtown Escondido, many are paying tribute to the nearly 3,000 innocent people who were killed in the attacks, as well as the sacrifices made by first responders. KUSI Newsroom, last_img read more

Simulation suggests nonwater based life could exist on Saturns moon Titan

first_img Explore further As scientists continue to search for life on other planets, more and more they are beginning to concede that if it does exist, it may not necessarily exist in the Goldilocks, or habitable zone. Such planets are all the “right” distance from their star, and hopefully, also have water. But recent evidence has suggested that some chemical reactions could lead to types of life forms where there is no water, which further suggests that it may exist outside of what is now considered the habitable zone. For life to come about in such places, researchers reason, there would likely need to be some sort of action going on—and that is why there has been so much focus on Titan; it is the only object in our solar system, besides Earth, that has both rainfall and erosion due to liquid movement. But the water it has is locked far underground and the moon is too cold to support an impact by water anyway. But, as the researchers with this new effort discovered after poring over data sent back by Huygens, the surface does have hydrogen cyanide in its sediment, brought down from the atmosphere by methane and ethane rain. It was those molecules that drove the design of the simulations—the team wanted to see if they could form the basis of reactions that could lead to the creation of polymers such as polyimine, which the team notes, are conducive to the formation of prebiotic reactions leading to a form of life. Their simulations showed that such reactions are possible and that the structures that came about were also able to absorb sunlight in the wavelengths present on the Titan surface.The researchers suggest their work, and that done by others indicates that a return to the planet by a new probe might be in order, one able to test for a different form of life, or at least its precursors. © 2016 Phys.org Life on other planets could be far more widespread, study finds An image of Titan’s surface, as taken by the European Space Agency’s Huygens probe as it plunged through the moon’s thick, orange-brown atmosphere on Jan. 14, 2005. Today, Cornell scientists have chemical evidence that suggests prebiotic conditions may exist there. Credit: ESA/NASA/JPL-Caltech/Univ. of Arizona This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Journal information: Proceedings of the National Academy of Sciences (Phys.org)—A team of researchers at Cornell University has built and run a simulation that showed prebiotic reactions could possibly occur on the surface of one of Saturn’s moons, Titan, suggesting the possibility of life evolving in a place where it is too cold for water to be a factor. In their paper published in Proceedings of the National Academy of Sciences, the team describes the simulation they created in response to the discovery (by the Huygens probe) that polymers such as polyimine might have already developed on the moon’s surface. Citation: Simulation suggests non-water based life could exist on Saturn’s moon Titan (2016, July 5) retrieved 18 August 2019 from https://phys.org/news/2016-07-simulation-non-water-based-life-saturn.html More information: Polymorphism and electronic structure of polyimine and its potential significance for prebiotic chemistry on Titan, PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1606634113AbstractThe chemistry of hydrogen cyanide (HCN) is believed to be central to the origin of life question. Contradictions between Cassini–Huygens mission measurements of the atmosphere and the surface of Saturn’s moon Titan suggest that HCN-based polymers may have formed on the surface from products of atmospheric chemistry. This makes Titan a valuable “natural laboratory” for exploring potential nonterrestrial forms of prebiotic chemistry. We have used theoretical calculations to investigate the chain conformations of polyimine (pI), a polymer identified as one major component of polymerized HCN in laboratory experiments. Thanks to its flexible backbone, the polymer can exist in several different polymorphs, which are relatively close in energy. The electronic and structural variability among them is extraordinary. The band gap changes over a 3-eV range when moving from a planar sheet-like structure to increasingly coiled conformations. The primary photon absorption is predicted to occur in a window of relative transparency in Titan’s atmosphere, indicating that pI could be photochemically active and drive chemistry on the surface. The thermodynamics for adding and removing HCN from pI under Titan conditions suggests that such dynamics is plausible, provided that catalysis or photochemistry is available to sufficiently lower reaction barriers. We speculate that the directionality of pI’s intermolecular and intramolecular =N–H…N hydrogen bonds may drive the formation of partially ordered structures, some of which may synergize with photon absorption and act catalytically. Future detailed studies on proposed mechanisms and the solubility and density of the polymers will aid in the design of future missions to Titan.Press releaselast_img read more

Life on exoplanets may give off a fluorescent glow

first_img Powered by Scientists at Cornell University say that life-bearing exoplanets may be detectable by their soft glow. Based on laboratory studies, the team led by Jack O’Malley-James at Cornell’s Carl Sagan Institute believes that a mechanism that protects organisms from hard ultraviolet radiation could make worlds beyond the solar system radiate a soft, detectable light.Anyone who has watched fireflies flitting about in the night sky is familiar with the idea of organisms producing light. Not only can some insects light up, but so can fish, squid, bacteria and many others, for a variety reasons that include attracting mates, camouflage, decoying prey, and marking territory. But there is another type of luminescence called “photoprotective biofluorescence,” which is a protective mechanism found in some species of undersea corals that live at a shallow enough depth for ultraviolet radiation from the Sun to penetrate. Normally, such radiation would be absorbed by the tissues, resulting in a nasty and possibly fatal case of marine sunburn, but these polyps have a trick up their non-existent sleeves.What happens is that biofluorescent proteins in the coral’s tissues absorb the UV radiation, exciting an electron and raising it to an unstable energy state. As the electron returns to its stable state it re-emits radiation in the visible band of the light spectrum. The result is that the UV is rendered harmless and the animal fluoresces. What occurred to the Cornell teams was that this mechanism could be handy to any extraterrestrial life that happened to evolve in a particularly nasty environment, such as in the habitable zone of M-type stars, where a large number of exoplanets have been found. M-type stars tend to emit ultraviolet flares, which is bad news for any organisms on planets orbiting them, but if they used biofluorescence to protect themselves, not only would this give them a fighting chance, it would also produce a biosignature that could be detected by telescopes when the flare hits the planet, causing it to temporarily fluoresce.To test this hypothesis, the team studied the spectral emissions of common fluorescent corals and used this to produce model spectra and colors that could be found on exoplanets orbiting M-type stars. They concluded that the strength of this glow could be enough to be detected by telescopes currently under development. “These biotic kinds of exoplanets are very good targets in our search for exoplanets, and these luminescent wonders are among our best bets for finding life on exoplanets,” says O’Malley-James.The research was published in the Monthly Notices of the Royal Astronomical Society.Source: Cornell University We recommend Google Analytics settings Privacy policy I consent to the use of Google Analytics and related cookies across the TrendMD network (widget, website, blog). Learn more Yes Nolast_img read more