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Category Archives: astronomy

Ice and "complex organic materials" on Mercury’s poles

This is one of those perplexing astronomical news that make history and I can’t but mention. US scientists have found, with the help of scout satellite MESSENGER,  that not just suspected Mercury’s polar water ice (in shadowed craters) is indeed that but also that confusing dark regions around it are complex organic materials, possibly darkened by the intense solar radiation that bathes the small inner planet. 

The team found that the probe’s reflectance measurements, taken via laser altimetry, matched up well with previously mapped radar-bright regions in Mercury’s high northern latitudes. Two craters in particular were bright, both in radar and at laser wavelengths, indicating the possible presence of reflective ice. However, just south of these craters, others appeared dark with laser altimetry, but bright in radar.

This confused scientists for a while but eventually they realized that the puzzling regions actually hold water ice at a meter’s depth into the soil, where the heat of the sun can’t reach so easily. 
Radar-reflectant regions (ice) show in yellow
The most interesting part however is that the astronomers are almost certain now that the dark material must be complex organic matter, darkened by the extreme solar radiation.
Is there life in Mercury? 
Source: Science Daily.
Ref studies: 
  1. David A. Paige, Matthew A. Siegler, John K. Harmon, Gregory A. Neumann, Erwan M. Mazarico, David E. Smith, Maria T. Zuber, Ellen Harju, Mona L. Delitsky, and Sean C. Solomon. Thermal Stability of Volatiles in the North Polar Region of Mercury. Science, 29 November 2012 DOI: 10.1126/science.1231106
  2. Gregory A. Neumann, John F. Cavanaugh, Xiaoli Sun, Erwan M. Mazarico, David E. Smith, Maria T. Zuber, Dandan Mao, David A. Paige, Sean C. Solomon, Carolyn M. Ernst, and Olivier S. Barnouin. Bright and Dark Polar Deposits on Mercury: Evidence for Surface Volatiles. Science, 29 November 2012 DOI: 10.1126/science.1229764
 
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Posted by on November 30, 2012 in astronomy, biology, chemistry, science, Solar System

 

Echoes from the Past (Nov 1)

Happy calaca day to all Mexicans. I have a bunch of interesting news items stored in the “to do” folder and it’s time to release them in bulk and, in a sense, get rid of them that way. Hope you find them interesting.
Prehistory and proto-history:

Abalone ochre container from Blombos
I already commented in the previous ‘Echoes’ edition but the 100,000 years-old paint containers made-out-of-shells found in Blombos (South Africa) have been echoing through various media, each with a  slightly different twist ··> The Heritage Journal, MSNBC, SD.
Nail in the coffin for ‘Clovis first’ theory: mammoth bone spear point in mammoth leg bone dated precisely to pre-Clovis times: 13,800 years ago (there are older dates out there anyhow) ··> BBC.
Jaw bone found near Kennewick Man’s site (and controversy on native insistence on reburial) ··> KPLU.

Cishan-Peligang pottery
Chinese Neolithic may be almost as old as West Asian one. Evidence of millet cultivation in Hebei (North China) dates to c. 10,000-8,700 years ago, within the Cishan culture (notice that Pengtoushan culture in South China overlaps with these dates and could be even quite older) ··> Xinhua
Bronze Age take-out windows found in Iran (Godin Tepe) ··> Unreported Heritage News, Live Science.
A new report on Iruña-Veleia Roman era graffiti supports their authenticity ··> Ostraka euskalduna[eu], where you can download the PDF in Spanish language by M. Thomson.
Also mentioned recently but still hitting the news, controversy on the reopening of Altamira cave, dubbed the Magdalenian Sistine Chapel, to the public ··> SD.

Replica of the Altamira ceiling (fragment)

Genetics:
Sardinian genetics point to pre-Neolithic origins according to new research (this I want to discuss in some greater detail but I’m sadly leaving for tomorrow again) ··> Daniela Contu et al. at PLoS ONE (open access). 
Researchers claim that mtDNA age estimates support pre-Neolithic dates for major East Asian population expansion ··> Hong-Xiang Zheng et al. at PLoS ONE (open access).
Fractal analysis of the human genome. You would think that putting together the words fractal and human genetics would appeal to my interest a lot. I must be getting old because it only does somewhat. A reason may be that while the methodology is intriguing and innovative no particular conclusion is proposed ··> Pedro A. Moreno et al. at BMC Genomics (open access).
Extra copies of SRGAP2 gene may be one reason behind human unique intelligence ··> Science News.
Human brains designed by the same fixated genes, regardless of race or individual differences. This is one of a list of novel findings on how the genome expresses in the brain along human life ··> SD.
Epigenetically modified nucleotide (“sixth letter” 5-hydroxymethylcytosine) in neuronal genomes is key to their behavior as such ··> SD.
Propensity for longer life inherited epi-genetically through generations. This so much coveted trait is inherited by lab roundworms even if the initial epigenetic modification has vanished ··> SD.
Other anthropology news:
Human children, but not chimpanzees, prefer to collaborate in order to solve tasks ··> Science Daily.
IQ is not totally fixed by genetics and can indeed change, specially in adolescence ··> BBC.
Other science news:
Comet storm detected in nearby stellar system (may increase chances of life by feeding planets like ours with water) ··> SD.
Nature laws may vary across the universe. At least electromagnetic constants seem to behave that way ··> PhysOrg.
Highly efficient (10x) hydrolysis catalyst found, helping to pave the way for easier production of hydrogen for fuel instead of dirty oil ··> SD.
Global warming is for real (in case you still had any doubt) ··> SD.

 

Echoes from the past (Sep 24)

And all the rest of the cool stuff in short headlines:

Archaeology and hominin evolution:
Robust australopithecines were indeed relatives, shows CT scan ··> SD.
Neanderthals also exploited seafood resources, as early as H. sapiens ··> El Neandertal tonto ¡qué timo![es].
Looters and bureaucracy destroy a Solutrean site in Andalusia (Higueral-Guardia cave). Sadly enough, it was a lot easier for looters to access the unprotected cave illegally than for archaeologists to do so legally ··> Pileta de Prehistoria[es].
What more classical troglodyte imagery than skulls on sticks? Sadly archaeology had never produced such artifacts… until now: Epipaleolithic Swedes had them ··> Pileta de Prehistoria[en].

Fascinating ‘Nazca lines’ found in Arabia ··> Live Science.

More Neolithic remains from Yesilova (Izmir, Turkey) ··>  Daily News.
Remember the first pampooty shoe (or abarka) found in Areni 1 cave (Armenia)? It has now also produced a skirt ··> News.am.
Bronze Age’s stone anchors from the Black Sea ··> Novinite.

Fscinating 3D reconstructions of Stonehenge, Woodhenge, etc. ··> The Heritage Journal.

Stanton Drew reconstruction
Cahokia Mounds researched in some depth finally ··>  BND.
Clay disks from Alaska ··> Art Daily.
 
Genetics:
A. thaliana
Bronze Age haploid DNA from North China yields no surprises (mtDNA: D4, D*, M7c, A4, F1b, G1a, M9a, M10 and M8z; Y-DNA: N1c and O3) ··> Dienekes.
First Aboriginal Australian genome sequenced ··> Dienekes.
Epigenetic evolution: Arabidopsis thaliana does it all the time, what about humans? ··> SD.
Other sciences:
Quite impressive stuff these days:
Speed of light may not be the ultimate speed limit: neutrinos found going faster. It also challenges the unidirectionality of time ··> Al Jazeera, BBC.
LHC, where the barriers of science are broken
Dark matter challenged by dwarf galaxies ··> BBC.

Dwarf galaxy getting cocky

Special thanks to Stone Pages’ Archaeo News section.

 

Echoes from the past (Sep 16)

A. sediba

Is Australopithecus sediba in fact Homo sediba? Both brain and hand (but also pelvis and ankle) make, in the opinion of some researchers, this australopithecine the best candidate for ancestor of our own principal ancestor: Homo erectus. Science Daily has a whole series on this theory and the facts that back it: 1, 2, 3 and 4 articles. Also at PhysOrg and some of the original papers at Science (pay per view of course): 1, 2, 3, 4, 5

More on the Southern Iberian Neolithic idols (in Spanish but with many nice photos) at Neolítico de la Península Ibérica.

The oldest ‘pub’ of Scotland? Chalcolithic or Neolithic (c. 4600 years ago) building at Jarlshof (Shetland) was at least a beer brewery and bakery. It is possible that the site was also used as tavern of some sort ··> Daily Record.

The Jarlshof brewery

Reproduction with Neanderthals was rare ··> France24 (and, update!, a criticism by John Hawks).

Ötzi, the Chalcolithic herder from La Lagozza culture, was also Y-DNA G2a according to a video reported by Dienekes. This is the second time that G2a (a relatively small haplogroup today of quite clear West Asian origins) has been reported in post-Cardial Neolithic peoples in Mediterranean Europe. Earlier this year it was reported in the majority of a related population of Occitania (SE French state), together with some I2a. It is notable that both populations were culturally related, not just because of their shared Cardium Pottery roots, but also because of the ChasseyLa Lagozza cultural fusion, which I’d dare suggest as precursor of the historical Ligures.

Still it is hard to explain the apparent high frequency of the lineage back then and the low one today (c. 5% on average across Europe). As for high tier exceptions, nowadays G (usually G2a in Europe) reaches 12% in mainland Italy,  14% in Sardinia (reaching as much as 21% in some locations), 12% in Corsica, 7% in Austrian Tyrol, up to 14% in some locations of Croatia, up to 11% in some locations of Greece, 13% in Moldova, 12% in Portugal and 8% in Spain. It may be a fluke that 2/3 known lineages from the Chassey-La Lagozza cultural complex are in this category (it is statistically quite reasonable) but we can’t of course avoid rising an eyebrow.

Caucasian and European peoples are not really very much related. A new paper confirms that Caucasus peoples are on their own (maybe related to Anatolia, not sampled) within the West Eurasian macro-population, clustering better with West Asians than Europeans in any case, even North Caucasus populations like Chechens and such. The paper by B. Yunusbayev is also PPV, so I’ll refer to Dienekes again, who includes nice, rather informative, graphs like this one:

Amber-trapped feathers show light on the evolution of birds and dinosaurs ··> BBC.

Astronomy and cosmology:

  • Preferred direction of spacetime challenges the Cosmological Principle which claimed that everything was equally boring ··> PhysOrg.
  • Fifty new exoplanets discovered in a row ··> BBC.
  • Star rips exoplanet to shreds with X rays ··> Discovery News.

And soon to come in this blog (in separate articles to be written later):

  • Is West African skull from Late Upper Paleolithic ‘archaic’ (meaning another species than Homo sapiens) ··> PLoS ONE.
  • Gene influences behavior but… culture influences the gene that influences behavior ··> Not Exactly Rocket Science.
 

Echoes from the past (Aug 29) – various interesting news

Follow here a series of links and comments on issues that are of some prehistoric or genetic interest (plus a well fed section of astronomy news this time), which I have got no time to deal with so far… or do not come with enough info to merit a separate entry… or are not of great interest to me.
Neanderthal trowel at Abric Romaní (Catalonia)

Print and reconstruction of the trowel
The almost hollow print of what once was a trowel (or similar) has been found at the important Paleolithic cave of Abric Romaní (Capellanes, Catalonia). The print came with some residues which indicate that the instrument was left at the fire when it was already off, so it did only burn superficially, later being deprived of oxygen by water and moss. 
The artifact’s length is of 32 cm, with a maximum width of 8 cm and may have been used to manage the fire. It is dated to 56,000 years ago.
··> El Mundo[es], Neanderfollia[cat].
More mammoth petroglyphs in North America
I recently mentioned a mammoth engraving from Florida, which should be from c. 13,000 BP. Another place where such engravings seem to exist is San Juan River, near Bluff (Utah).
That is what Ekkehart Malotki and Henry D. Wallace argue in a paper published at Stone Pages, which includes many images of petroglyphs, only a few of which look like mammoths, one of them very clearly so.

The mammoth (left, eroded) has a bison partially superimposed (right)

Opium ritual and medicinal use in Iberian Neolithic

Ritual use was some times associated to these idols
The opium poppy grows spontaneously in most of Europe, specially in the Mediterranean. I was knowledgeable that Western Danubian farmers had grown and used this narcotic in Germany and nearby areas but this is the first explicit reference I know of its use in the Mediterranean basin or the Iberian peninsula.
Sadly this material is in Spanish language and I don’t have room nor time here to deal with it properly. Hopefully later on.
The evidence of use of this drug is analyzed in several sites, most of them in Andalusia but also from Catalonia…
Paleolithic findings from Triacastela, Galicia
Pileta de Prehistoria[es] also tells us of research in a relatively ill-documented region: Galicia. The findings at Triacastela are from the Middle Paleolithic (Neanderthals) and Upper Paleolithic (H. sapiens). From this last period a decorated dart has been found:

Documentary on destroyed archaeological site

The last bit I want to highlight from Pileta is a documentary (in Spanish) on the destruction by private businesspeople of the archaeological patrimony of the cave of Chaves (Aragon). I already mentioned this crime against humankind in 2010 at my old blog.
··> Chaves la Memoria expoliada (video at Pileta de Prehistoria, in Spanish, 55 mins).
Archaic immune introgression?
I mentioned in June some speculation on HLA (immune system) introgression from Neanderthals or other archaic Homo in Asia. The corresponding paper has been published with more data but is pay per view (supp. material is accessible however). Back in the day I thought it looked at least partly unlikely (as the corresponding haplotypes are in some cases found in Africa).
Przewalski horses at the origin of domesticated horse Y-DNA

While horse mtDNA is most diverse and suggests many origins, all known Y-DNA comes from a single lineage… which happens to be related to that of the Przewalski wild horses of Mongolia via an ancient intermediate lineage located at Tuva Republic.
Ancient wild horses from Siberia and Alaska however had much greater Y-DNA diversity.
··> Science Daily, Nature (PPV).
Tunisian lineages
Dienekes mentions two new papers on Tunisian Y-DNA (and one of them also on mtDNA), yet they are both pay per view and the announced results seem not really novel. Anyhow, for the reference, they are:
Snow White and the red apple

Artistic rendering of Snow White
Unnamed Dwarf Planet (Snow White 2007 OR10) gives us some new information on itself and the Kuiper Belt. To begin with Snow White happens to be red in fact, what requires some explanation. 
Mike Brown, the man who demoted Pluto and discovered Eris, Sedna and a host of other Transneptunian objects, explains it in detail in three successive entries at his blog: The redemption of Snow White (part 1, part 2 and part 3).
Also news story at Science Daily.

Panspermia? Yes but from Earth outwards

Panspermia is the theory that proposes that life (in its primitive forms) may have arrived to Earth from outer space. Modeling of meteorite impacts however suggest that the opposite may also be true. These impacts could well have ejected materials with terrestrial life such as bacteria or even those hardy water bugs known as tardigrades, which can withstand almost anything.
So ‘earthling’ life may already exist on Mars, Venus or other planets, moons or asteroids of the Solar System… and there was no need for human-made spacecrafts for them to make such journeys. 
Direct evidence will have to wait however: it is just a model.
··> BBC.
    Diamond planet
    Extremely compressed carbon seems to be what a planet, once a white dwarf star, is made of. That is like saying that the whole planet is the largest known diamond ever. 
    Sadly for those thinking about mining it, it lays at 4000 light-years of distance, 1/8 of the path from here to the Galactic Center.
    ··> SD.

     

    Many more interesting short news

    Earliest known dog
    A lot of them, but not all, come via Stone Pages’ Archaeo News.
    Just to get you interested: oldest dog ever, oldest people in America… and the Bubbliverse!
    (Not drooling yet?! You’re reading the wrong blog then).
    Europe

    Spain: Andalusian caves were explored with bee wax lamps (candles) and not animal wax ones (which would have been cumbersome). Exposition on this matter on Aug. 10 in Puente Viesgo, Cantabria. ··> Pileta de Prehistoria[es].
    Wales: Tests confirm age of Wales rock art. (Direct communication of Prof. Nash to Stone Pages’ ArchaeoNews).
    Scotland: Sainbury site was sort of Epipaleolithic rest stop. ··> BBC.
    Bulgaria: Chalcolithic burial found in Pomorie ··> The Sofia Echo.
    Sardinia: 300 menhirs (standing stones) found. ··> L’Uninone Sarda[it], Sardegna 24[it].
    Italy: early Etruscan holy site, dated c. 1000 BCE, found near Viterbo. ··> ANSA, UPI.
    Asia
    Siberia: Earliest dog skull found in Altai, dated to 33,000 years ago. It has short snout like dogs but long fangs like wolves. ··> BBC, Daily Mail, PLoS ONE (I may write more later on this).
    Japan: Chinese style tools were introduced to Japan c. 25-20,000 years ago. ··> Xinhua.
    Jordan: Ancient city of Tell Qarqur could withstand massive drought c. 2000 BCE. ··> Live Science.
    India: Sebalpani rock paintings may be from historical period. ··> DNA India.
    America
    USA: Oldest evidence of human presence in all North America  found near Salado, Texas. The site has been dated to c. 15,500 BP and has yielded some 16,000 artifacts already. ··> WFAA.
    Canada: Evidence of human presence c. 10,000 years ago, near Penfield, New Brunswick. A highway’s design has been changed to preserve the site. ··> CBC.
    Mexico: Olmec relief 2800 years old found in Chalcatzingo, Morelos ··> Latin American Herald Tribune.
    Africa / human evolution
    Australopithecus sediba proposed missing link between australopithecines and humans. ··> National Geographic.
    Genetics & biology
    Alternative splicing to explain mammal brain capabilities. Genes alone cannot account for the improved mammal neural complexity. ··> Science Daily.
    Astronomy & cosmology
    Multiverse confirmed: our Universe just a bubble among many. Identification in the gamma radiation background by objective computer program adds weight to the idea that other bubble-universes have left their marks on ours. ··> Science Daily.

    Welcome to the Bubbliverse, earthlings!
     

    A one-dimensional universe at the Big Bang?

    This is so weird and intriguing that I can’t but make a quick comment on it. Two US scientists, Jonas Mureika and Dejan Stojovic, are proposing a radical rethink of what we understand as the basic physics of our universe: they suggest that, at the Big Bang, the Universe had only one dimension (like a line), acquiring then two dimensions (plane) and then three (space), and probably soon a fourth (if not already). 
    This radical rethink seems to have been pushed by the advances (and lack of them) in the fields of Physics and Astrophysics in the last decades, when questions have been piling up and convincing answers have been lacking instead. 
    These problems include the fundamental incompatibility between gravito-centric General Relativity and particle-centric Quantum Mechanics, the mystery of the Universe’s accelerating expansion (which seems to demand extra dimensions) and serious issues with the elusive (and maybe non-existent) Higg’s Boson. 
    By reflecting this new proposal I do not mean to adhere to it but I do like the principle they begin from: maybe something fundamental is wrong in the way we think Physics, so exploring radically new venues may be the way out of an otherwise unsolvable problem. 
    They are thinking out of the box and that is something I really like and that often brings real solutions in all fields. 
    The new theory has been published in the Physical Review Letter (pay per view) and is also discussed in its essentials at Science Daily.
     
    1 Comment

    Posted by on April 21, 2011 in astronomy, physics, science