Saturday, January 23, 2016

BBC News - Cave paintings change ideas about the origin of art

BBC News - Cave paintings change ideas about the origin of art:

The artworks are in a rural area on the Indonesian Island of Sulawesi.
Until now, paintings this old had been confirmed in caves only in Western Europe.

"It is a really important find; it enables us to get away from this Euro-centric view of a creative explosion that was special to Europe and did not develop in other parts of the world until much later," he said.

Saturday, January 16, 2016

Seattle-area dig uncovers 10,000-year-old stone tools - SFGate

Seattle-area dig uncovers 10,000-year-old stone tools

By the time excavations were done, crews had unearthed more than 4,000 stone flakes, scrapers, awls and spear points crafted at least 10,000 years ago by some of the region’s earliest inhabitants.
“We were pretty amazed,” said archaeologist Robert Kopperl, who led the field investigation. “This is the oldest archaeological site in the Puget Sound lowland with stone tools.”
Kopperl and his colleagues published their initial analysis earlier this year in the journal PaleoAmerica. He’ll discuss the findings Saturday morning in a presentation sponsored by theRedmond Historical Society.
The discovery is yielding new insights into the period when the last ice age was drawing to a close and prehistoric bison and mammoths still roamed what is now Western Washington.
The site on the shores of Bear Creek, a tributary to the Sammamish River, appears to have been occupied by small groups of people who were making and repairing stone tools, said Kopperl, of SWCA Environmental Consultants.

Dwarf planet Ceres: water vapor in Occator crater

Dwarf planet Ceres: water vapor in Occator crater:

When the Sun shines into the Occator crater on the surface of the dwarf planet Ceres, a kind of thin haze appears above its brightest spot. This can be seen in images taken by the camera system aboard NASA's Dawn space probe, which researchers under the lead of the Max Planck Institute for Solar System Research published on 9 December, 2015 in Nature magazine.

The haze indicates that frozen water may exist near the surface . The bright spots in the Occator crater likely contain magnesium sulphates, a class of mineral salts. Many of the other bright areas on Ceres' surface most likely by now consist solely of dried mineral salts. The new results show that since the birth of the Solar System frozen water has been able to survive not only in its furthest reaches, but also in the comparatively close asteroid belt.

Saturday, January 9, 2016

Climate at -354 (Pluto)

Where Math Meets Pluto | Pluto New Horizons:

In hindsight, one wonders why we were so surprised. For instance, the triple point (the location on the temperature-pressure phase diagram in which a material can coexist as solid, liquid and gas) of both carbon monoxide and molecular nitrogen is in the vicinity of 63 Kelvin (- 346 Fahrenheit), a temperature that is achievable on Pluto, given its distance from the sun.  We know from the Earth that when a system is near its triple point (as in the case of water), interesting phases can manifest, such as flowing water, glaciers and vapor. This is one of the reasons why the Earth and its surface morphology is such a cool place—no pun intended.

When we look at Pluto we see the informally-named Sputnik Planum (SP), which is probably a giant nitrogen ice sea, with a lot of methane and carbon monoxide to share the space. It has the texture of toothpaste and has flow timescales on the order of dozens of years.  We see in the surrounding mountain ranges evidence of glacier ice flowing into the basin of SP. The ice within the plains appears to be undergoing so-called “solid-state convection,” the overturning of the ice layer because it’s warmer below than above, which causes it to buoyantly rise to the surface. We see perplexing textures that look like pits and worms on various parts of SP, a phenomenon possibly due to the strong sublimation of nitrogen or possibly even methane. We see globules of glacier ice that look like coagulated jelly in various locations near the glacier flows.

Wednesday, January 6, 2016

Giant comets could pose danger to life on Earth |

Giant comets could pose danger to life on Earth:

Centaurs are typically 30–60 miles (50–100 kilometers) across, or larger, and a single such body contains more mass than the entire population of Earth-crossing asteroids found to date. Calculations of the rate at which Centaurs enter the inner solar system indicate that one will be deflected onto a path crossing Earth’s orbit about once every 40,000–100,000 years. While in near-Earth space, they are expected to disintegrate into dust and larger fragments, flooding the inner solar system with cometary debris and making impacts on our planet inevitable.

Known severe upsets of the terrestrial environment and interruptions in the progress of ancient civilizations, together with our growing knowledge of interplanetary matter in near-Earth space, indicate the arrival of a Centaur around 30,000 years ago. This giant comet would have strewn the inner planetary system with debris ranging in size from dust all the way up to lumps several kilometers across.

Specific episodes of environmental upheaval around 10,800 BCE and 2,300 BCE, identified by geologists and paleontologists, are also consistent with this new understanding of cometary populations. Some of the greatest mass extinctions in the distant past, for example the death of the dinosaurs 65 million years ago, may similarly be associated with this giant comet hypothesis

Saturday, January 2, 2016

Megatsunami: Evidence of 800-Foot Wave Worries Experts : Environment : Nature World News

Megatsunami: Evidence of 800-Foot Wave Worries Experts : Environment : Nature World News:

Around 73,000 years ago, the towering predecessor of the Fogo volcano - one of the most active in the world - collapsed. As a result, a unbelievably massive tsunami rippled across the Atlantic Ocean, washing its destructive force over islands that now boast over 250,000 human residents. Experts now wonder if such a disaster is more common than we'd like.

That, as it turns out, is exactly what scientists working off the west African coast in the Cape Verde Islands have found. Several years ago Ricardo Ramalho, a researcher with Columbia University's Lamont-Doherty Earth Observatory, spotted unusual boulders lying as far as 2,000 feet inland and nearly 650 feet above sea level. They were kind of hard to miss -- big as delivery vans and completely out of place, lying on volcanic ground where limestone and basalt boulders do not belong.