70,000 years ago a Star passed through our Solar System



An alien star passed through our Solar System just 70,000 years ago, astronomers have discovered.





Eric E. Mamajek1, Scott A. Barenfeld2, Valentin D. Ivanov3,4, Alexei Y. Kniazev5,6,7, Petri Väisänen5,6,Yuri Beletsky8, and Henri M. J. Boffin3

Published 2015 February 12© 2015. The American Astronomical Society. All rights reserved.
The Astrophysical Journal Letters, Volume 800, Number 1


Passing stars can perturb the Oort Cloud, triggering comet showers and potentially extinction events on Earth. We combine velocity measurements for the recently discovered, nearby, low-mass binary system WISE J072003.20-084651.2 (“Scholz’s star”) to calculate its past trajectory. Integrating the Galactic orbits of this ~0.15 M binary system and the Sun, we find that the binary passed within only 52+23−14 kAU (0.25+0.11−0.07 pc) of the Sun 70+15−10 kya (1σuncertainties), i.e., within the outer Oort Cloud. This is the closest known encounter of a star to our solar system with a well-constrained distance and velocity. Previous work suggests that flybys within 0.25 pc occur infrequently (~0.1 Myr−1). We show that given the low mass and high velocity of the binary system, the encounter was dynamically weak. Using the best available astrometry, our simulations suggest that the probability that the star penetrated the outer Oort Cloud is ~98%, but the probability of penetrating the dynamically active inner Oort Cloud (<20 kAU) is ~10−4. While the flyby of this system likely caused negligible impact on the flux of long-period comets, the recent discovery of this binary highlights that dynamically important Oort Cloud perturbers may be lurking among nearby stars.


Perturbations by passing stars on Oort cloud comets have previously been proposed as the source of long-period comets visiting the planetary region of the solar system (Oort 1950; Biermann et al. 1983; Weissman 1996; Rickman 2014), and possibly for generating Earth-crossing comets that produce biological extinction events (Davis et al. 1984). Approximately 30%, of craters with diameters <10 km on the Earth and Moon are likely due to long-period comets from the Oort Cloud (Weissman 1996). Periodic increases in the flux of Oort cloud comets due to a hypothetical substellar companion have been proposed (Whitmire & Jackson 1984); however, recent time series analysis of terrestrial impact craters are inconsistent with periodic variations (Bailer-Jones 2011), and sensitive infrared sky surveys have yielded no evidence for any wide-separation substellar companion (Luhman 2014). A survey of nearby field stars with Hipparcosastrometric data (Perryman et al. 1997) by García-Sánchez et al. (1999) identified only a single candidate with a pass of within 0.9 pc of the Sun (Gl 710; 1.4 Myr in the future at ~0.34 pc); however, it is predicted that ~12 stars pass within 1 pc of the Sun every Myr (García-Sánchez et al. 2001). A recent analysis by Bailer-Jones (2014) of the orbits of ~50,000 stars using the revisedHipparcos astrometry from van Leeuwen (2007), identified four Hipparcos stars whose future flybys may bring them within 0.5 pc of the Sun (however, the closest candidate HIP 85605 has large astrometric uncertainties; see discussion in Section 3).

A low-mass star in the solar vicinity in Monoceros, WISE J072003.20-084651.2 (hereafter W0720 or “Scholz’s star”) was recently discovered with a photometric distance of ~7 pc and initial spectral classification of M9 ± 1 (Scholz 2014). This nearby star likely remained undiscovered for so long due to its combination of proximity to the Galactic plane (b = +2fdg3), optical dimness (V = 18.3 mag), and low proper motion (~0farcs1 yr−1). The combination of proximity and low tangential velocity for W0720 (Vtan sime 3 km s−1) initially drew our attention to this system. If most of the star’s motion was radial, it was possible that the star may have a past or future close pass to the Sun. Indeed, Burgasser et al. (2014) and Ivanov et al. (2014) have recently reported a high positive radial velocity. Burgasser et al. (2014) resolved W0720 as a M9.5+T5 binary and provided a trigonometric parllax distance of 6.0+1.2−0.9 pc. Here we investigate the trajectory of the W0720 system with respect to the solar system, and demonstrate that the star recently (~70,000 years ago) passed through the Oort Cloud.

A Medieval Remedy that Kills MRSA (Methicillin Resistant Staphylococcus Aureus)







A 1,000-Year-Old Antimicrobial Remedy with Antistaphylococcal Activity

Freya Harrison,a Aled E. L. Roberts,a Rebecca Gabrilska,b Kendra P. Rumbaugh,b Christina Lee,c Stephen P.

Digglea Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom a ; Department of Surgery, Texas Tech University Health Sciences Center, School of Medicine, Lubbock, Texas, USA b; School of English and Centre for the Study of the Viking Age, University of Nottingham, University Park, Nottingham, United Kingdom c


Plant-derived compounds and other natural substances are a rich potential source of compounds that kill or attenuate pathogens that are resistant to current antibiotics. Medieval societies used a range of these natural substances to treat conditions clearly recognizable to the modern eye as microbial infections, and there has been much debate over the likely efficacy of these treatments. Our interdisciplinary team, comprising researchers from both sciences and humanities, identified and reconstructed a potential remedy for Staphylococcus aureus infection from a 10th century Anglo-Saxon leechbook. The remedy repeatedly killed established S. aureus biofilms in an in vitro model of soft tissue infection and killed methicillin-resistant S. aureus (MRSA) in a mouse chronic wound model. While the remedy contained several ingredients that are individually known to have some antibacterial activity, full efficacy required the combined action of several ingredients, highlighting the scholarship of premodern doctors and the potential of ancient texts as a source of new antimicrobial agents. IMPORTANCE While the antibiotic potential of some materials used in historical medicine has been demonstrated, empirical tests of entire remedies are scarce. This is an important omission, because the efficacy of “ancientbiotics” could rely on the combined activity of their various ingredients. This would lead us to underestimate their efficacy and, by extension, the scholarship of premodern doctors. It could also help us to understand why some natural compounds that show antibacterial promise in the laboratory fail to yield positive results in clinical trials. We have reconstructed a 1,000-year-old remedy which kills the bacteria it was designed to treat and have shown that this activity relies on the combined activity of several antimicrobial ingredients. Our results highlight (i) the scholarship and rational methodology of premodern medical professionals and (ii) the untapped potential of premodern remedies for yielding novel therapeutics at a time when new antibiotics are desperately needed.

Integrated fish and plant farming




Food and Agriculture Organization of the United Nations
Rome, 2014


Somerville, C., Cohen, M., Pantanella, E., Stankus, A. & Lovatelli, A. 2014.
Small-scale aquaponic food production. Integrated fish and plant farming.
FAO Fisheries and Aquaculture Technical Paper No. 589. Rome, FAO. 262 pp.

Aquaponics is a symbiotic integration of two mature disciplines: aquaculture and hydroponics. This technical paper discusses the three groups of living organisms (bacteria, plants and fish) that make up the aquaponic ecosystem. It presents management strategies and troubleshooting practices, as well as related topics, specifically highlighting the advantages and disadvantages of this method of food production. This publication discusses the main theoretical concepts of aquaponics, including the nitrogen cycle, the role of bacteria, and the concept of balancing an aquaponic unit. It considers water quality, testing and sourcing for aquaponics, as well as methods and theories of unit design, including the three main methods of aquaponic systems: media beds, nutrient film technique, and deep water culture. The publication includes other key topics: ideal conditions for common plants grown in aquaponics; chemical and biological controls of common pests and diseases including a compatible planting guide; common fish diseases and related symptoms, causes and remedies; tools to calculate the ammonia produced and biofiltration media required for a certain amount of fish feed; production of homemade fish food; guidelines and considerations for to establishing aquaponic units; a cost-benefit analysis of a small-scale, media bed aquaponic unit; a comprehensive guide to building small-scale versions of each of the three aquaponic methods; and a brief summary of this publication designed as a supplemental handout for outreach, extension and education. Aquaponics is an integrated approach to efficient and sustainable intensification of agriculture that meets the needs of water scarcity initiatives. Globally, improved agricultural practices are needed to alleviate rural poverty and enhance food security. Aquaponics is residue-free, and avoids the use of chemical fertilizers and pesticides. Aquaponics is a labour-saving technique, and can be inclusive of many gender and age categories. In the face of population growth, climate change and dwindling supplies of water and arable land worldwide, developing efficient and integrated agriculture techniques will support economic development.


Storing information digitally, forever (?)

Paper; Grass, R. N., Heckel, R., Puddu, M., Paunescu, D. and Stark, W. J. (2015), Robust Chemical Preservation of Digital Information on DNA in Silica with Error-Correcting Codes. Angew. Chem. Int. Ed., 54: 2552–2555. doi:10.1002/anie.201411378


Robust Chemical Preservation of Digital Information on DNA in Silica with Error-Correcting Codes


Information, such as text printed on paper or images projected onto microfilm, can survive for over 500 years. However, the storage of digital information for time frames exceeding 50 years is challenging. Here we show that digital information can be stored on DNA and recovered without errors for considerably longer time frames. To allow for the perfect recovery of the information, we encapsulate the DNA in an inorganic matrix, and employ error-correcting codes to correct storage-related errors. Specifically, we translated 83 kB of information to 4991 DNA segments, each 158 nucleotides long, which were encapsulated in silica. Accelerated aging experiments were performed to measure DNA decay kinetics, which show that data can be archived on DNA for millennia under a wide range of conditions. The original information could be recovered error free, even after treating the DNA in silica at 70 °C for one week. This is thermally equivalent to storing information on DNA in central Europe for 2000 years.



Five years in space for NASA’s Solar Dynamics Observatory

February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory, which provides incredibly detailed images of the whole sun 24 hours a day. Capturing an image more than once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the sun grow and erupt ever since its launch on Feb. 11, 2010. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.

In honor of SDO’s fifth anniversary, NASA has released a video showcasing highlights from the last five years of sun watching. Watch the movie to see giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the sun’s surface.

The imagery is an example of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths – and therefore different temperatures – scientists can watch how material courses through the corona, which holds clues to what causes eruptions on the sun, what heats the sun’s atmosphere up to 1,000 times hotter than its surface, and why the sun’s magnetic fields are constantly on the move.

Five years into its mission, SDO continues to send back tantalizing imagery to incite scientists’ curiosity. For example, in late 2014, SDO captured imagery of the largest sun spots seen since 1995 as well as a torrent of intense solar flares. Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the sun, achieves escape velocity and heads off into space. In this case, the sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.

Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.

Half of all DNA present on the NYC subway’s surfaces matches no known organism



The Paper;

Geospatial Resolution of Human and Bacterial Diversity with City-Scale Metagenomics


In Brief
Afshinnekoo et al. describe a city-scale molecular profile of DNA collected from a city’s subway system, public surfaces, and one waterway. These data enable a baseline analysis of bacterial, eukaryotic, and aracheal organisms in the built environment of mass transit and urban


  • Almost half of all DNA present on the subway’s surfaces matches no known organism.
  • Hundreds of species of bacteria are in the subway, mostly harmless. More riders bring more diversity.
  • One station flooded during Hurricane Sandy still resembles a marine environment.
  • Human allele frequencies in DNA on surfaces can mirror US Census data.


The panoply of microorganisms and other species present in our environment influence human health and disease, especially in cities, but have not been profiled with metagenomics at a city-wide scale. We sequenced DNA from surfaces across the entire New York City (NYC) subway system, the Gowanus Canal, and public parks. Nearly half of the DNA (48%) does not match any known organism; identified organisms spanned 1,688 bacterial, viral, archaeal, and eukaryotic taxa, which were enriched for harmless genera associated with skin (e.g.,Acinetobacter). Predicted ancestry of human DNA left on subway surfaces can recapitulate U.S. Census demographic data, and bacterial signatures can reveal a station’s history, such as marine-associated bacteria in a hurricane-flooded station. Some evidence of pathogens was found (Bacillus anthracis), but a lack of reported cases in NYC suggests that the pathogens represent a normal, urban microbiome. This baseline metagenomic map of NYC could help long-term disease surveillance, bioterrorism threat mitigation, and health management in the built environment of cities.

The News:

Researchers at Weill Cornell Medical College released a study on Thursday that mapped DNA found in New York’s subway system — a crowded, largely subterranean behemoth that carries 5.5 million riders on an average weekday, and is filled with hundreds of species of bacteria (mostly harmless), the occasional spot of bubonic plague, and a universe of enigmas. Almost half of the DNA found on the system’s surfaces did not match any known organism and just 0.2 percent matched the human genome.

“People don’t look at a subway pole and think, ‘It’s teeming with life,’ ” said Dr. Christopher E. Mason, a geneticist at Weill Cornell Medical College and the lead author of the study. “After this study, they may. But I want them to think of it the same way you’d look at a rain forest, and be almost in awe and wonder, effectively, that there are all these species present — and that you’ve been healthy all along.”

Building the first digital life form. Open source.

If the brain is a collection of electrical signals, then, if you could catalog all those those signals digitally, you might be able upload your brain into a computer, thus achieving digital immortality.

While the plausibility—and ethics—of this upload for humans can be debated, some people are forging ahead in the field of whole-brain emulation. There are massive efforts to map the connectome—all the connections in the brain—and to understand how we think. Simulating brains could lead us to better robots and artificial intelligence, but the first steps need to be simple.

So, one group of scientists started with the roundworm Caenorhabditis elegans, a critter whose genes and simple nervous system we know intimately.



OpenWorm aims to build the first comprehensive computational model of the Caenorhabditis elegans (C. elegans), a microscopic roundworm. With only a thousand cells, it solves basic problems such as feeding, mate-finding and predator avoidance. Despite being extremely well studied in biology, this organism still eludes a deep, principled understanding of its biology.

Songs of Whales




The International Whaling Commission banned commercial hunting of humpbacks in 1966, followed by all baleen whales — some of which also sing — and sperm whales in 1986, a moratorium that still stands today. But while that helped several species dodge extinction, it couldn’t undo centuries of slaughter. The global humpback population has grown from about 5,000 in 1966 to more than 60,000 today, but roughly 1.5 million existed before the 19th century. Many other whales have had less success rebounding, including the North Atlantic right whale and the Western Pacific gray whale.

Biological Privacy


Biological surveillance is the means by which biological science is used to track, monitor, analyze, and turn bodies into data. It is the extraction of DNA and microbes from our skin, nails, hair and body fluids. It is the analysis of identifying body parts like faces, fingerprints and irises. It is the tracking of life itself by body heat, pulse, perspiration, and involuntary movement. It is the vulnerability we each face every day by the very situation of being human, by simply having a body. Biononymous.me fosters molecular resistance through the creation of a community to openly discuss, research, and develop potential solutions through art, science, technology, policy, and theory. Be Biononymous.

An ancient (11 billion years old!) extrasolar system with five sub-Earth-size planets


Its age is estimated to be more than 11 billion years old, far older than the Sun. These are old, old planets!


Paper: http://arxiv.org/abs/1501.06227

An ancient extrasolar system with five sub-Earth-size planets

T. L. Campante, T. Barclay, J. J. Swift, D. Huber, V. Zh. Adibekyan, W. Cochran, C. J. Burke, H. Isaacson, E. V. Quintana, G. R. Davies, V. Silva Aguirre, D. Ragozzine, R. Riddle, C. Baranec, S. Basu, W. J. Chaplin, J. Christensen-Dalsgaard, T. S. Metcalfe, T. R. Bedding, R. Handberg, D. Stello, J. M. Brewer, S. Hekker, C. Karoff, R. Kolbl, N. M. Law, M. Lundkvist, A. Miglio, J. F. Rowe, N. C. Santos, C. Van Laerhoven, T. Arentoft, Y. P. Elsworth, D. A. Fischer, S. D. Kawaler, H. Kjeldsen, M. N. Lund, G. W. Marcy, S. G. Sousa, A. Sozzetti, T. R. White
(Submitted on 26 Jan 2015)
The chemical composition of stars hosting small exoplanets (with radii less than four Earth radii) appears to be more diverse than that of gas-giant hosts, which tend to be metal-rich. This implies that small, including Earth-size, planets may have readily formed at earlier epochs in the Universe’s history when metals were more scarce. We report Kepler spacecraft observations of Kepler-444, a metal-poor Sun-like star from the old population of the Galactic thick disk and the host to a compact system of five transiting planets with sizes between those of Mercury and Venus. We validate this system as a true five-planet system orbiting the target star and provide a detailed characterization of its planetary and orbital parameters based on an analysis of the transit photometry. Kepler-444 is the densest star with detected solar-like oscillations. We use asteroseismology to directly measure a precise age of 11.2+/-1.0 Gyr for the host star, indicating that Kepler-444 formed when the Universe was less than 20% of its current age and making it the oldest known system of terrestrial-size planets. We thus show that Earth-size planets have formed throughout most of the Universe’s 13.8-billion-year history, leaving open the possibility for the existence of ancient life in the Galaxy. The age of Kepler-444 not only suggests that thick-disk stars were among the hosts to the first Galactic planets, but may also help to pinpoint the beginning of the era of planet formation.

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