‏إظهار الرسائل ذات التسميات natural. إظهار كافة الرسائل
‏إظهار الرسائل ذات التسميات natural. إظهار كافة الرسائل
الخميس، 30 يناير 2014

It's raining, it's pouring...molten iron: Scientists create first ever weather map of a 'brown dwarf'

Luhman 16B is the nearest brown dwarf to Earth, and the third nearest star system to our solar system

Scientists have created the first ever weather map of an unusual category of star known as a ‘brown dwarf’, unveiling in the process a new contender for the title of ‘worst weather in the universe’.
The surface of Luhman 16B is pelted with molten iron rain that falls from clouds made up of a gaseous form of the metal alongside other minerals. Temperatures are equally hellish, touching around 2,000F or 1,100C.
Scientists involved in the study described the planet as “extremely inclement".
At a distance of 6.5 light years from Earth, Luhman 16B is the nearest brown dwarf to our planet. These unusual objects are sometimes known as failed stars: they’re larger than gas giant planets such as Jupiter, but they’re still too small to achieve the cycle of nuclear fusion that defines a true star. The first brown dwarf was only confirmed by astronomers just 20 years ago.
"Previous observations have inferred that brown dwarfs have mottled surfaces, but now we can start to directly map them," said Ian Crossfield of the Max Planck Institute for Astronomy, lead author of one of the two new studies, in an official statement.
Surface map of Luhman 16B recreated from VLT observations. Credit: ESO / I. Crossfield
"What we see is presumably patchy cloud cover, somewhat like we see on Jupiter."
Crossfield and his team at the Max Planck institute used a technique known as Doppler imaging to create a weather map of Luhman 16B using the European Southern Observatory’s Very Large Telescope.
"In the future, we will be able to watch cloud patterns form, evolve and dissipate — eventually, maybe exo-meteorologists will be able to predict whether a visitor to Luhman 16B can expect clear or cloudy skies," said Crossfield in a statement.
A second study headed by Beth Biller of the University of Edinburgh went to greater depths, examining brighter and darker clouds as the planet rotated (each rotation takes four hours) and using their observations to recreate what happens at different layers of the atmosphere.
“The exciting bit is that this is just the start,” said Biller. “With the next generations of telescopes, and in particular the 39 m European Extremely Large Telescope, we will likely see surface maps of more distant Brown Dwarfs – and eventually, a surface map for a young giant planet."
The results of the first study will appear in the journal Nature, whilst detailed atmospheric data will feature in the Astrophysical Journal Letters.
الثلاثاء، 28 يناير 2014

New species of river dolphin discovered in the Amazon


New species of river dolphin

discovered in the Amazon

Meet the Araguaian Boto, the first species of river dolphin discovered in nearly a century.



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The Amazon river dolphin (Inia geoffrensis) - the closest relative of the Araguaian Boto (Inia araguaiaensis) (Wikimedia Commons)
Scientists are always discovering new species — around 15,000 per year — and you can read all about the highlights of 2013 here. Today, we learned about a new species that's promising to be a highlight of 2014.
A team of scientists from the Federal University of Amazonas in Manaus, Brazil have discovered a new species of freshwater river dolphin in the Amazon, the BBC reports. The small group of dolphins was living in the Araguaian basin, where they were assumed to be Amazon river dolphins (Inia geoffrensis) that had broken off from the larger population.
Not so, the scientists reported in the journal Plos One. DNA tests showed that the population of dolphins were genetically distinct from their dolphin cousins and that the species likely diverged more than two million years ago.
River dolphins are extremely rare, and the Araguaian Boto is the first new species to be discovered since 1918, when scientists found the Yangtze river dolphin (Lipotes vexillifer) in China.
The Yangtze river dolphin became extinct in 2006, and the Araguaian Boto population faces its own threats. The scientists who discovered the new dolphin recommended that the International Union for Conservation of Nature (IUCN) classify the new species as "vulnerable."
The world is so cool.
http://www.globalpost.com/dispatch/news/science/140123/new-species-river-dolphin-discovered-the-amazon

German cows cause methane blast in Rasdorf

German cows cause methane blast in Rasdorf

Farmer and his cows (library image) Cows each produce hundreds of litres of methane a day, and methane can have explosive potential if it reaches the right concentrations

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Methane gas released by dairy cows has caused an explosion in a cow shed in Germany, police said.
The roof was damaged and one of the cows was injured in the blast in the central German town of Rasdorf.
Thanks to the belches and flatulence of the 90 dairy cows in the shed, high levels of the gas had built up.
Then "a static electric charge caused the gas to explode with flashes of flames" the force said in a statement quoted by Reuters news agency.
Emergency services attended the farm and took gas readings to test for the risk of further blasts, said local media.
Cows are believed to emit up to 500 litres of methane - a potent greenhouse gas - each per day.


Russian squirrel pack 'kills dog'

Black squirrel (archive)
Local people suggest hunger is driving squirrels to extremes
Squirrels have bitten to death a stray dog which was barking at them in a Russian park, local media report.

Passers-by were too late to stop the attack by the black squirrels in a village in the far east, which reportedly lasted about a minute.
They are said to have scampered off at the sight of humans, some carrying pieces of flesh.
A pine cone shortage may have led the squirrels to seek other food sources, although scientists are sceptical.
The attack was reported in parkland in the centre of Lazo, a village in the Maritime Territory, and was witnessed by three local people.
A "big" stray dog was nosing about the trees and barking at squirrels hiding in branches overhead when a number of them suddenly descended and attacked, reports say.

"They literally gutted the dog," local journalist Anastasia Trubitsina told Komsomolskaya Pravda newspaper.
"When they saw the men, they scattered in different directions, taking pieces of their kill away with them."
Mikhail Tiyunov, a scientist in the region, said it was the first he had ever heard of such an attack.
While squirrels without sources of protein might attack birds' nests, he said, the idea of them chewing a dog to death was "absurd".
"If it really happened, things must be pretty bad in our forests," he added.
Komosmolskaya Pravda notes that in a previous incident this autumn chipmunks terrorised cats in a part of the territory.
A Lazo man who called himself only Mikhalich said there had been "no pine cones at all" in the local forests this year.
"The little beasts are agitated because they have nothing to eat," he added.