News Article | December 26, 2016
A new San Francisco-based organization called METI, or Messaging Extra Terrestrial Intelligence, plans to send signals to distant planets, rather than waiting for them to call Earth. By the end of 2018, the project aims to send some conversation-starters via radio or laser signals to a rocky planet circling Proxima Centauri, the nearest star other than the sun, and then to more distant destinations, hundreds or thousands of light years away. It would be the first effort to send powerful, repeated and intentional messages into space, targeting the same stars over months or years. "If we want to start an exchange over the course of many generations, we want to learn and share information," said Douglas Vakoch, president of METI and former director of Interstellar Message Composition at the Search for Extraterrestrial Intelligence Institute in Mountain View, Calif.,, known as SETI. Founded last year, METI will host two workshops next year, one in Paris and the other in St. Louis. It also plans to start raising the $1 million needed annually to staff and build or borrow a powerful transmitter in a remote location. Part of the mission will be to figure out how to craft the perfect message to say "Hello." Like much else in science, the project has turned controversial. Some ask: If aliens are hostile, do we really want them to know where we are? We shouldn't draw attention to ourselves, say science fiction writer David Brin and theoretical physicist Stephen Hawking. "We have almost zero idea of whether aliens are likely to be dangerous," physicist Mark Buchanan wrote in journal Nature Physics. Other experts say it's worth waiting until we're better conversationalists - and, then, use use well-established groups with international consultation. "Babbling babies are not always appreciated during adult conversation," said Andrew Fraknoi, chair of the astronomy department at Foothill College in Los Altos Hills. "Listening and learning is how children become adults, and why not try that for a while?" Others endorse the effort. "I'd be happy to see this done," said Seth Shostak, senior astronomer with the SETI Institute. "I think there's something to be learned, nothing to be feared, and at least the possibility of discovering something truly revolutionary: We have company nearby." "By reflecting on how we can communicate what it means to be human to someone who is not human, we view ourselves differently," said METI treasurer Dalia Rawson, a former dancer with Ballet San Jose and now managing director of the Silicon Valley Ballet. "By looking at our bodies, our movements, and our dance through the eyes of an alien, we gain a renewed appreciation of what it means to be uniquely human." There have been plenty of other efforts to connect with aliens, but they've come in fits and starts. There are no regulations for sending signals into space. In the early 1970s, NASA's Pioneer 10 and 11 spacecraft carried a message in the form of a gold plaque, then a phonograph record (stylus included). SETI's Frank Drake beamed a radio message that could be assembled into a pictogram of images. More recently, we've sent arithmetic, concerts of Vivaldi and Gershwin, and the Beatles song "Across the Universe." SETI and the $100 million Breakthrough Listen project at the University of California, Berkeley, funded by internet entrepreneur Yuri Milner, scans space in hope of finding some signature of alien technology. "If everyone who can send a message decides only to receive messages, it will be a very quiet galaxy," Fraknoi said. Explore further: Should we call the cosmos seeking ET? Or is that risky?
News Article | December 16, 2016
Some of the planets discovered around stars in our own galaxy could be very similar to arid Tatooine, watery Scarif and even frozen Hoth, according to NASA scientists. Sifting through data on the more than 3,400 confirmed alien worlds, scientists apply sophisticated computer modeling techniques to tease out the colors, light, sunrise and sunsets we might encounter if we could pay them a visit. Some of these distant worlds are even stranger than those that populate the latest Star Wars film, "Rogue One: A Star Wars Story." And others are eerily like the fictional planets from a galaxy far, far away. A real planet in our galaxy reminded scientists so much of Luke Skywalker's home planet, they named it "Tatooine." Officially called Kepler-16b, the Saturn-sized planet is about 200 light-years away in the constellation Cygnus. The reality of its two suns was so startling, George Lucas himself agreed to the astronomers' nickname for the planet. "This was the first honest-to-goodness real planetary system where you would see the double sunset as two suns," said Laurance Doyle, an astrophysicist with the Search for Extraterrestrial Intelligence Institute and Director of the Institute for the Metaphysics of Physics, who discovered the planet using NASA's Kepler space telescope. A person on Kepler-16b would have two shadows. In a storm, two rainbows would appear. Each sunset would be unique, because the stars are always changing their configuration. Building a sundial would require calculus. Astronomers have discovered that about half of the stars in our Milky Way galaxy are pairs, rather than single stars like our sun. So while Kepler-16b aka Tatooine is probably too cold and gaseous to be home to life, or a hopeful desert farm boy, it's a good bet that there might be a habitable Tatooine "twin" out there somewhere. George Lucas has a fondness for desert planets, and at least one NASA scientist thinks he's on the right track. "Desert planets are possible. We have one right here in our solar system in Mars. We think desert planets elsewhere could be even more habitable than Mars is," said Shawn Domagal-Goldman, an astrobiologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. He likes Lucas' proliferation of arid worlds because he believes it might reflect the galaxy we live in. "The recurring theme of desert worlds in 'Star Wars' is really interesting, because there is some research that shows that these would be likely habitable worlds to find," said Domagal-Goldman, who is, among other things, a climate scientist. Desert worlds are not only a very real possibility, but they are probably very common, he said. They could be hot, like Tatooine and Jakku, or cold, like Mars and Jedha in "Rogue One." "The lack of water on a desert planet might be what makes it more habitable. Water amplifies changes to climates and can cause planets to end up being really hot like Venus, or really cold like Europa," said Domagal-Goldman. There is a world named Hoth in our galaxy—an icy super-Earth discovered in 2006. It reminded scientists so much of the frozen Rebel base they unofficially nicknamed it after the planet that appears in "The Empire Strikes Back." The planet's scientific designation is OGLE 2005-BLG-390L, after the Optical Gravitational Lensing Experiment (OGLE) that found it. Our galaxy's Hoth is too cold to support life as we know it. But life may evolve under the ice of a different world, or a moon in our solar system. On Earth, it's been found inside volcanoes, deep ocean trenches, even the frozen soil of Antarctica. NASA is currently designing a Europa mission to look for life under the crust of Jupiter's icy moon Europa. And Saturn's moon Enceladus also contains an underground ocean that could harbor alien life. For the scientists who characterize exoplanets, the most important planet to study is Earth-the only known planet with life. And life on Earth began in the ocean. "We need Earth climate science to help us understand planetary habitability and the potential diversity of life on exoplanets," said astrobiologist Nancy Kiang, a research scientist at NASA's Goddard Institute for Space Studies. As an astrobiologist, her job is to model the kind of plant life that might exist on planets around other stars—also known as exoplanets. We haven't confirmed the existence of ocean worlds like the perpetually rainy Kamino in "Attack of the Clones," or worlds with oceans, like the beachy Scarif from "Rogue One." But we have found frozen ocean worlds in our solar system, in the moons Europa and Enceladus. We may even be able to glimpse an ocean on an exoplanet in the not-so-distant future. "Ocean glint can be detected over large distances," said Victoria Meadows, a professor at the University of Washington and director of the NASA Astrobiology Institute's Virtual Planetary Laboratory. Such a glint was first observed reflecting from the liquid methane seas on Titan, the largest moon of Saturn. Both the forest moon of Endor, from "Return of the Jedi," and Takodana, the home of Han Solo's favorite cantina in "The Force Awakens," are green like our home planet. But astrobiologists think that plant life on other worlds could be red, black, or even rainbow-colored. A few months ago, astronomers from the European Southern Observatory announced the discovery of Proxima Centauri b, a planet only 4 light-years away from Earth, which orbits a tiny red star. "The star color would be peachy to the human eye," Meadows said. "And the planet would appear dark purple to light purple, looking at it from a spacecraft." From the surface of Proxima b, the sky would appear to be periwinkle. The light from a red star, also known as an M dwarf, is dim and mostly in the infrared spectrum, as opposed to the visible spectrum we see with our sun. The planet also doesn't have sunrises or sunsets like Earth: one side always faces its sun. "If you have photosynthetic organisms, they would always get fixed amounts of light all the time. It would be a permanent sunset around the planet. You would see a gradation of color," Kiang said. Just as seaweed changes color from green to dark brown as you dive deeper into the ocean, plants on a red dwarf planet may brilliantly change color from the day side to the night side. And that could mean rainbow plant life. Just about any 'Star Wars' planet In the "Star Wars" universe, Lucas and company envision scores of worlds bustling with intelligent beings. In our galaxy, we know of only one such world so far-Earth. But NASA exoplanet scientist think we have a fighting chance of finding life beyond our solar system. The next few years will see the launch of a new generation of spacecraft to search for planets around other stars. The Transiting Exoplanet Survey Satellite (TESS) and NASA's James Webb Space Telescope will attempt to determine what's in the atmospheres of other planets. Then, in the next decade, the Wide Field Infrared Survey Telescope (WFIRST) will bring us images of exoplanets around sun-like stars. That's one step closer to finding life. "The idea of life on other planets resonates with people on a very personal level," Doug Hudgins, NASA's program scientist for exoplanet exploration, said of the "Star Wars" films' enduring popularity. "They portray this image of a universe that is teeming with life." "We are at our heart explorers," he said. "We want to know what's out there. Through the imaginings of George Lucas and Gene Roddenberry, we get to feel for a bit of time like we really can go out and explore the stars." Explore further: Tatooine worlds orbiting two suns often survive violent escapades of aging stars
Horneck G.,German Aerospace Center |
Klaus D.M.,University of Colorado at Boulder |
Mancinelli R.L.,Search for Extraterrestrial Intelligence Institute
Microbiology and Molecular Biology Reviews | Year: 2010
The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Wolfire M.G.,University of Maryland University College |
Hollenbach D.,Search for Extraterrestrial Intelligence Institute |
McKee C.F.,University of California at Berkeley
Astrophysical Journal | Year: 2010
The mass of molecular gas in an interstellar cloud is often measured using line emission from low rotational levels of CO, which are sensitive to the CO mass, and then scaling to the assumed molecular hydrogen H2 mass. However, a significant H2 mass may lie outside the CO region, in the outer regions of the molecular cloud where the gas-phase carbon resides in C or C+. Here, H2 self-shields or is shielded by dust from UV photodissociation, whereas CO is photodissociated. This H2 gas is "dark" in molecular transitions because of the absence of CO and other trace molecules, and because H2 emits so weakly at temperatures 10K
News Article | January 26, 2017
Dwarf planet Ceres, the largest known object in the asteroid belt and the lone dwarf planet in the inner solar system, is camouflaged by a layer of dust that disguises the true composition of its surface, findings of a new study suggest. Data collected by NASA's Dawn spacecraft, which has been orbiting the extraterrestrial body for almost two years, and ground-based telescopes suggest that the surface of Ceres harbors water-bearing minerals such as clays and carbonates. Observations made by NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), a modified Boeing 747 jet equipped with a 100-inch-wide telescope, however, hint that Ceres is not necessarily a carbon-rich body. Using data collected by SOFIA, astronomers detected a substantial amount of material on the surface of the dwarf planet that appears to be the debris of other asteroids. The "interplanetary dust particles" that often blaze up meteors when they collide with Earth's atmosphere are known to accumulate on the surface of smaller asteroids but it appears that they also build up on Ceres. The findings suggest that the body is coated by material that has partly disguised its real makeup. Astronomer Franck Marchis, from the Search for Extraterrestrial Intelligence Institute, said that they found that the outer few microns of the dwarf planet's surface are partially cloaked with dry particles. The particles though do not come from Ceres itself but these are debris from asteroid impacts that may have happened millions of years ago. "The most plausible scenario is that Ceres' surface has been partially contaminated by exogenous enstatite-rich material, possibly coming from the Beagle asteroid family," the researchers wrote in their study, which was published in the Astronomical Journal on Jan. 16. Ceres and 75 percent of all identified asteroids are in composition class "C" based on their similar colors. The new data gathered by SOFIA, however, revealed that Ceres is substantially different from neighboring C-type asteroids, which challenges conventional knowledge about the relationship of the dwarf planet and smaller asteroids. The findings also offered hints on the history of the dwarf planet. "This scenario questions a similar origin for Ceres and the remaining C-types, and it possibly supports recent results obtained by the Dawn mission that Ceres may have formed in the very outer solar system," the researchers said. Researchers likewise said that the findings shed light on questions about surface materials of asteroids accurately reflecting their intrinsic composition. "Our results show that by extending observations to the mid-infrared, the asteroid's underlying composition remains identifiable despite contamination by as much as 20 percent of material from elsewhere," said Pierre Vernazza, from Laboratoire d'Astrophysique de Marseille. Researchers are studying Ceres as it may provide information on the processes involved in the formation of planet Earth and the solar system. Last year, astronomers revealed that early in its history, the dwarf planet was a water world. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | February 18, 2017
BOSTON—In less than a decade, NASA will send a spacecraft to Jupiter’s moon Europa. Once there, a lander will navigate the world’s icy surface for about 20 days and attempt to probe its hypothesized . In less than a decade, NASA will send a spacecraft to Jupiter’s moon Europa. Once there, a lander will navigate the world’s icy surface for about 20 days and attempt to probe its hypothesized vast subsurface ocean . But whether Europa contains life, how can we avoid contaminating it with our own? That was the focus of a session here yesterday at the annual meeting of AAAS, which publishes Part of the problem, said session speaker Norine Noonan, a biologist at the University of South Florida in Tampa who previous served as chair of NASA’s Planetary Protection Advisory Committee, is that humans are “autonomous microbial growth distribution systems.” Our bodies “spew fountains of bacteria,” she told attendees, and these microbes hitch rides on sensitive space equipment despite efforts to sterilize it. “If you take a $2 billion rover to Mars to study the organic microbes you brought with you, it’s not cost effective.” Such organic pollution isn’t just bad science. It also violates Article IX of the Outer Space Treaty of 1967 , which mandates the exploration of “the moon and other celestial bodies so as to avoid their harmful contamination and also adverse changes in the environment of the earth resulting from that introduction of extraterrestrial matter.” “Planetary protection doesn’t affect most of the proposals NASA’s going to get,” John Rummel, a biologist at the Search for Extraterrestrial Intelligence Institute in Mountain View, California, who organized the session, tells . “Just missions that want to bring back samples and flagship missions to Europa and Mars.” So how can we avoid bringing little green microbes to Europa’s little green men? Kevin Hand, an astrobiologist at NASA’s Jet Propulsion Laboratory in Pasadena, California, writes in an email that his team plans to build the Europa lander in a clean facility, then “bake out” any remaining microbes by bombarding it with high heat. The spacecraft is then wrapped in a biobarrier, an aluminum foil–like sheath that keeps out any errant contaminants until it reaches Jupiter's moon. These strategies have been “implemented before, so there is good heritage for our approach,” he says. According to Rummel, this is the first time since the Viking missions to Mars in 1975 that a full-system sterilization—meaning every component of the spacecraft—is planned for a planetary lander. “It probably costs about 10% more to design it [the spacecraft] like this,” he says. But the cost is worth it. “Whatever lands on the surface of Europa will have less than a one in 10,000 chance of contaminating its surface,” Hand told attendees. “We have to protect Europa for Europans.”
Jenniskens P.,Search for Extraterrestrial Intelligence Institute
Journal of Spacecraft and Rockets | Year: 2010
Spectroscopic observations of the 2006 Stardust Sample Return Capsule entry are presented, obtained by means of a slitless miniature echelle spectrograph onboard NASA's DC-8 airborne laboratory. The data cover the wavelength range from 336 to 880 nm, at 0.14-0.9 nm resolution, and were obtained during the time interval when radiative heating was most important. The data contain a broadband continuum, presumably from the hot heat-shield surface, shock-layer air plasma emissions of N, O, and N2, and atomic hydrogen and CN molecular band emission from the ablating heat-shield material, a form of phenol-impregnated carbon ablator. Early in flight, there were also atomic line emissions of Zn, K, Ca+, and Na, presumably from a white Z-93P paint applied to the top of the phenol- impregnated carbon ablator. At each moment along the trajectory, the whole spectrum was recorded simultaneously, but broken into smaller segments. Key issues addressed in the data reduction and calibration are described. The interpretation of these data was given elsewhere.
Fairen A.G.,Search for Extraterrestrial Intelligence Institute
Nature Geoscience | Year: 2010
The northern plains of Mars are thought to have harboured an ocean more than 3.6 billion years ago. Delta deposits and river-valley termini ring the proposed seabed and define an equipotential palaeoshoreline. © 2010 Macmillan Publishers Limited. All rights reserved.
Cuzzi J.N.,NASA |
Estrada P.R.,Search for Extraterrestrial Intelligence Institute |
Astrophysical Journal, Supplement Series | Year: 2014
As small solid grains grow into larger ones in protoplanetary nebulae, or in the cloudy atmospheres of exoplanets, they generally form porous aggregates rather than solid spheres. A number of previous studies have used highly sophisticated schemes to calculate opacity models for irregular, porous particles with sizes much smaller than a wavelength. However, mere growth itself can affect the opacity of the medium in far more significant ways than the detailed compositional and/or structural differences between grain constituents once aggregate particle sizes exceed the relevant wavelengths. This physics is not new; our goal here is to provide a model that provides physical insight and is simple to use in the increasing number of protoplanetary nebula evolution and exoplanet atmosphere models appearing in recent years, yet quantitatively captures the main radiative properties of mixtures of particles of arbitrary size, porosity, and composition. The model is a simple combination of effective medium theory with small-particle closed-form expressions, combined with suitably chosen transitions to geometric optics behavior. Calculations of wavelength-dependent emission and Rosseland mean opacity are shown and compared with Mie theory. The model's fidelity is very good in all comparisons we have made except in cases involving pure metal particles or monochromatic opacities for solid particles with sizes comparable to the wavelength. © 2014. The American Astronomical Society. All rights reserved..
Brown A.J.,Search for Extraterrestrial Intelligence Institute
Icarus | Year: 2014
Scattering by particles significantly smaller than the wavelength is an important physical process in the icy and rocky bodies in our Solar System and beyond. A number of observations of spectral bluing (referred to in those papers as 'Rayleigh scattering') on planetary surfaces and cometary comas have been recently reported, however, the necessary mathematical modeling of this phenomenon has not yet achieved maturity. This paper is a first step to this effect, by examining the effect of grain size and optical index on the albedo of small conservative and absorbing particles as a function of wavelength. The conditions necessary for maximization of spectral bluing effects in real-world situations are identified. We find that any sufficiently narrow size distribution of scattering particles will cause spectral bluing in some part of the EM spectrum regardless of its optical index. We also investigate the effect of including a distribution of particle sizes. © 2014.