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Mon, 25 Sep 2017
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Nebula

100K nearby galaxies show no signs of advanced technological civilizations, lack technosignatures

© unknown
After examining some 100,000 nearby large galaxies in 2015 a team of researchers lead by The Pennsylvania State University astronomer Jason Wright concluded that none of them contain any obvious signs of highly advanced technological civilizations. Turning his focus closer to home this past spring of 2017, Wright proposed that an advanced civilization-an indigenous technological species could have arisen in the solar system before Earth-bound life did. Wright suggests that traces of its technology-"technosignatures"-may have survived, provided they were made of material not easily degraded by erosion or time and may remain hidden awaiting discovery under the surface of Venus and Mars.

"As we improve our understanding of ancient Earth and the history of our solar system, perhaps we may someday uncover evidence that suggests the activity of another technological civilization right here in our neighborhood," said Andrew Siemion, the director of Berkeley's SETI Research Center.


Galaxy

Astronomers find Milky Way's satellite galaxies to be unusually quiet

© Alamy stock photo
Early results from the Satellites Around Galactic Analogs (SAGA) Survey indicate that the Milky Way's satellites are much more tranquil than other systems of comparable luminosity and environment.
We might be more special than thought, astronomers have revealed.

A new study has discovered the Milky Way, which is home to Earth and its solar system, could in fact be an outlier, and not a 'normal' galaxy as they had previously thought.

Early results from the Satellites Around Galactic Analogs (SAGA) Survey indicate that the Milky Way's satellites are much more tranquil than other systems of comparable luminosity and environment.

The Milky Way, which is home to Earth and its solar system, is host to several dozen smaller galaxy satellites which orbit around the Milky Way and are useful in understanding the Milky Way itself.

Many satellites of those 'sibling' galaxies are actively pumping out new stars, but the Milky Way's satellites are mostly inert, the researchers found.

This is significant, according to the researchers, because many models for what we know about the universe rely on galaxies behaving in a fashion similar to the Milky Way.

'We use the Milky Way and its surroundings to study absolutely everything,' said Yale astrophysicist Marla Geha, lead author of the paper, which appears in the Astrophysical Journal.

'Hundreds of studies come out every year about dark matter, cosmology, star formation, and galaxy formation, using the Milky Way as a guide.

Blue Planet

Scientists hypothesize heat-pipe cooling was involved in evolution of all terrestrial planets including early Earth

© University of Hong Kong
Scientists have long been intrigued by the surfaces of terrestrial bodies other than Earth which reveal deep similarities beneath their superficially differing volcanic and tectonic histories.

A team of scientists from NASA, Hampton University and the University of Hong Kong propose a new way of understanding the cooling and transfer of heat from terrestrial planetary interiors and how that affects the generation of the volcanic terrains that dominate the rocky planets. Based on the present dynamics of Jupiter's tidally heated moon, Io, the scientists hypothesize that the geological histories of the solar system's terrestrial bodies, specifically Mercury, Venus, Moon and Mars, are consistent with a mode of early planetary evolution involving heat-pipes. They further propose that heat-pipe cooling is a universal process that may explain the common features seen on the surfaces of terrestrial planets.

The team's findings are discussed in a paper recently published in Earth and Planetary Science Letters.

Life Preserver

End-of-life chatbot can help you with difficult final decisions

© Hero Images/Getty
A chatbot could help
Could chatbots lend a non-judgemental ear to people making decisions about the end of their life? A virtual agent that helps people have conversations about their funeral plans, wills and spiritual matters is set to be trialled in Boston over the next two years with people who are terminally ill.

People near the end of their lives sometimes don't get the chance to have these important conversations before it's too late, says Timothy Bickmore at Northeastern University in Boston, Massachusetts. So Bickmore and his team - which included doctors and hospital chaplains - built a tablet-based chatbot to offer spiritual and emotional guidance to people that need it. "We see a need for technology to intervene at an earlier point," he says.

Info

Neanderthal kids brains grew more slowly than humans

© Paleoanthropology Group MNCN-CSIC
Skeleton of the Neanderthal boy recovered from the El Sidrón cave in Asturias, Spain.
The brains of Neanderthal children developed more slowly than those of anatomically modern humans, according to an analysis of a 49,000 year-old juvenile skeleton found in a cave in northwestern Spain.

The analysis was conducted by a team led by palaeobiologist Antonio Rosas of the Museo Nacional de Ciencias Naturales in Madrid, and published in the journal Science.

The scientists found that the Neanderthal child, reliably established to have been 7.7 years old at death, had a brain that was about 87.7% the size of an adult. Human children have a brain 95% of adult size by the same age.

The team also found that some of the child's vertebrae had not fused, while in humans the same bones are fully fused between the ages of four and six.

The skeleton was recovered from the El Sidron cave system in Asturias in Spain, a hotspot for Neanderthal research that has so far produced more than 2,500 remains of seven adults and six juveniles.

Comet 2

Unique 'ring comet' discovered by Hubble telescope

© ESA/Hubble
With the help of the NASA/ESA Hubble Space Telescope, a German-led group of astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet. The research is presented in a paper published in the journal Nature today.

In September 2016, just before the asteroid 288P made its closest approach to the Sun, it was close enough to Earth to allow astronomers a detailed look at it using the NASA/ESA Hubble Space Telescope [1].

The images of 288P, which is located in the asteroid belt between Mars and Jupiter, revealed that it was actually not a single object, but two asteroids of almost the same mass and size, orbiting each other at a distance of about 100 kilometres. That discovery was in itself an important find; because they orbit each other, the masses of the objects in such systems can be measured.

But the observations also revealed ongoing activity in the binary system. "We detected strong indications of the sublimation of water ice due to the increased solar heating - similar to how the tail of a comet is created," explains Jessica Agarwal (Max Planck Institute for Solar System Research, Germany), the team leader and main author of the research paper. This makes 288P the first known binary asteroid that is also classified as a main-belt comet.

Telescope

NASA's Hubble spots 'unique' binary asteroid between Mars and Jupiter

© hubblesite.org/NASA
Astronomers, with the aid of the Hubble Space Telescope, have discovered a unique binary object lurking in the asteroid belt between Mars and Jupiter.

The object, an asteroid first discovered by Spacewatch back in 2006, was reexamined again last September. Hubble took a number of images of the asteroid, designated 288P, just before it made its closest approach to the sun.

Upon studying the images, boffins realised that it was not one but two asteroids of roughly the same size and mass, orbiting each other at a distance of about 60 miles, sporting a comet-esque tail, making 288P the first known binary asteroid that is also classified as a main-belt comet.


Comet

A solar eruption 'photobombed' the Mars encounter with Comet Siding Spring

© Don Davis / IUVS Team
An artist's conception of the martian meteor shower due to Comet Siding Spring. The comet has passed the planet in this image, and is shown left and above the planet, heading towards the outer solar system. The planet's atmosphere is exaggerated to highlight the presence of a coherent group of meteors due to the comet's debris stream.
When Comet C/2013 A1 (Siding Spring) passed just 140,000 kilometres from Mars on 19th October 2014, depositing a large amount of debris in the martian atmosphere, space agencies coordinated multiple spacecraft to witness the largest meteor shower in recorded history. It was a rare opportunity, as this kind of planetary event occurs only once every 100,000 years. However, scientists analysing the data have found that a very powerful Coronal Mass Ejection (CME) launched by the Sun also arrived at Mars 44 hours before the comet, creating significant disturbances in the martian upper atmosphere and complicating analysis of the data. Results describing the combined effects of the comet and the CME throughout the martian atmosphere are being presented in a special session at the European Planetary Science Congress (EPSC) 2017 in Riga on Thursday, 21st September.

Snowflake Cold

Data shows massive Arctic Ice gain over past five years

"Science is the belief in the ignorance of the experts" - Richard Feynman

Arctic sea ice extent is up 40% from this date five years ago.
© National Snow and Ice Data Center
Sea extent ice comparisons: 2012 2017

Greenland's surface gained ten times as much ice as it did five years ago, and was the fifth highest on record.
© polarportal.org

Comment: The real story is more nuanced. It is possible to have both Arctic ice gain and melting permafrost, if you don't try to ascribe them to the same mechanisms.

Melting permafrost is associated with methane pockets bubbling up to the surface. This implies heating from within, such as undetected movements of magma and, there can still be a general cooling trend if one looks to solar activity as a driver, instead of man's puny effect on the atmosphere.


Archaeology

Neanderthals may have died out due to competition with homo sapiens for food resources

© Martin Meissner/Associated Press
The findings showed that just like the Neanderthals, early modern humans or our ancestors had mainly mammoth and plants on their plates, creating a battle for food that Neanderthals lost.
Early modern humans and Neanderthals shared a similar diet -- consisting mainly of mammoth and plants -- and also competed for food which led to their downfall, new research has claimed.

"According to our results, Neanderthals and the early modern humans were in direct competition in regard to their diet, as well -- and it appears that the Neanderthals drew the short straw in this contest," said Dorothee Drucker, biogeologist from the University of Tubingen in Germany.

The first representatives of Homo sapiens colonized Europe around 43,000 years ago, replacing the Neanderthals there approximately 3,000 years later.

"Many studies examine the question of what led to this displacement -- one hypothesis postulates that the diet of the anatomically modern humans was more diverse and flexible and often included fish," added Herve Bocherens from the University of Tubingen.