Science & TechnologyS


Fireball

'Every' meteorite fall on earth mapped

Or at least those we know about. And where are the known meteorite landing places on earth? These impact zones show where scientists have found meteorites, or the impact craters of meteorites, some dating back as far as the year 2,300BC. The data is from the US Meteorological Society and doesn't show those places where meteorites may have fallen but not been discovered.

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© The Guardian

Comment: Note the falls appear to concentrate over populated areas. While this could be explained by saying that naturally more meteorites will be found in areas where there are more people, we have to wonder if masses of people can act as some sort of 'attractor' for these things...

To find out more, check out Comets and the Horns of Moses.


Fireball

Russian fireball won't be last surprise asteroid attack

meteorito en Rusia
© Reuters
The world will have to live with surprise asteroid attacks on the scale of Friday's Russian fireball, at least for a while.

The meteor that exploded over the Russian city of Chelyabinsk without warning Friday (Feb. 15), damaging hundreds of buildings and wounding more than 1,000 people, was caused by a space rock about 50 feet (15 meters) wide, researchers said.

Asteroids of this size are both difficult to detect and incredibly numerous, so it will take a long time for astronomers to find and map out the orbits of all the potentially dangerous ones. Besides, researchers have bigger fish to fry.

"Defending the Earth against tiny asteroids such as the one that passed over Siberia and impacted there is a challenging issue that is something that is not currently our goal," Paul Chodas, a scientist with the Near Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., told reporters Friday (Feb. 15).

"We are focusing on the larger asteroids first," Chodas added. "They are the ones that are the most hazardous."

Fireball 4

Third largest asteroid impact crater discovered in Southern Australia

Impact Crater
© Joao Virissimo/Shutterstock
A massive asteroid that crashed into Earth left behind a large impact crater in Australia and changed the entire landscape of the planet, scientists from the Australian National University (ANU) and University of Queensland claim in a recently-published study.

According to Stuart Gary of ABC News in Australia, the impact zone is centered in the East Warburton Basin in the northeastern part of South Australia.

It was created by an asteroid believed to be more than twelve miles (20 km) wide that crashed into the planet sometime between 360 million and 298 million years ago, the authors reported in the latest edition of the journal Tectonophysics.

Info

Quaoar, a rocky world orbiting beyond Neptune

Quaoar
© VegaStar CarpentierArtist’s impression of 50000 Quaoar, Neptune and our sun by VegaStar Carpentier in Paris. Thank you, VegaStar!
VegaStar Carpentier in Paris passed along this artist's impression of 50000 Quaoar, a small rocky world with its own moon, located in the outer solar system. It's massive enough to be considered a dwarf planet - much as Pluto is now considered a dwarf planet - under new guidelines from the International Astronomical Union (IAU). But the IAU hasn't recognized Quaoar as a dwarf planet, yet. VegaStar wrote:
This is an artistic view in the foreground Quaoar, Neptune, and our sun ..
What is Quaoar?

Michael Brown and Chadwick Trujillo of the California Institute of Technology in Pasadena discovered this object in 2002. It is extremely faint as seen from Earth, but they used the large Palomar 48-inch telescope to notice it creeping in front of the star background. Its motion in front of the stars showed that it is closer to us than the stars, a member of our own solar system. From the first, Quaoar appeared relatively bright for such a distant object, but it was too small for even large telescopes to see in any detail.

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Images & animations of 2012 DA14 close approach

Asteroid 2012 DA14 had a close approach with Earth at 1925 UT on 2013 Feb. 15. at about 0.09 LD (Lunar Distances = ~384,000 kilometers) or 0.0002 AU (1 AU = ~150 million kilometers). For more info about this asteroid and its close approach see our previous post.

Below you can find a selection (in chronological order) of our images & animations taken before, during and after the close approach.

Image of 2012 DA14 taken remotely from Australia on February 15, 2013 at 17:40UT. Exposure time 5 seconds with a 0.50-m f/6.8 astrograph + CCD + f/4.5 focal reducer from Q62 (iTelescope Observatory, Siding Spring). The asteroid was then of magnitude ~9.5 and moving at ~1140 "/min and less than 2 hours before its close approach of 19:25UT.
DA14 Asteroid
© Remanzacco Observatory
Here you can see a short animation made by using 3x5-second exposures.

Fireball

Smokescreen? NASA experts discuss Russia meteor in media teleconference today

NASA experts will hold a teleconference for news media at 4 p.m. EST today to discuss a meteor that streaked through the skies over Russia's Urals region this morning.

Scientists have determined the Russia meteor is not related to asteroid 2012 DA14 that will safely pass Earth today at a distance of more than 17,000 miles. Early assessments of the Russia meteor indicate it was about one-third the size of 2012 DA14 and traveling in a different direction.

Panelists for the teleconference are:
-- Bill Cooke, lead for the Meteoroid Environments Office at NASA's Marshall Space Flight Center in Huntsville, Ala.
-- Paul Chodas, research scientist in the Near Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

News media interested in participating should dial 888-843-7186 and use the passcode METEOR.

The teleconference will be carried live online. For detailed information concerning the Earth flyby of 2012 DA14, visit here.

Heart

Celestial Valentine

Generations of stars can be seen in this infrared portrait from NASA's Spitzer Space Telescope. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region).
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© NASA
Younger stars line the rims of the cavities, and some can be seen as pink dots at the tips of the elephant-trunk-like pillars. The white knotty areas are where the youngest stars are forming. Red shows heated dust that pervades the region's cavities, while green highlights dense clouds.

Info

Animal provides genetic clue to recent human evolution

Skull
© Flickr A clue for the incidence of recent human evolution has been discovered by researchers.
Scientists may have found a clue for discovering the incidence of recent human evolution. Researchers were able to find a single mutation that produces several traits common in East Asian peoples, from thicker hair to denser sweat glands.

The findings, published in the journal Cell, examined a mutation that had previously been identified as a strong candidate for positive selection. That is, the mutation would have given an evolutionary advantage to individuals.

The mutation itself was for an ectodysplasin receptor, or EDAR, which was part of a signaling pathway known to play a role in the development of hair, sweat glands and other skin features.

Although human populations in Africa and Europe had one, most East Asian populations had a variant of it called EDAR370A, which studies linked to thicker scalp hair and altered tooth shape in humans.

Fish

Anxiety drug found in rivers changes fish behaviour

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© AlamyThe effect of the drug on European perch (above) was similar to its effect on people, with potential evolutionary and ecological impacts.
Normally shy perch became bolder and more independent when exposed to a drug called oxazepam for treating anxiety

Drugs to treat anxiety in people may alter the behaviour of fish when the chemicals are flushed into rivers, according to scientists. Swedish researchers found that European perch exposed to tiny concentrations of a drug became less sociable, ate more and became more adventurous - all changes in behaviour that could have unexpected ecological impacts on fish populations.

When scientists at Umeå University in Sweden screened rivers for pharmaceuticals they found that a drug for treating anxiety, called oxazepam, was accumulating in fish. Many drugs and other synthetic chemicals used by humans in everything from pesticides to cosmetics can pass through waste water treatment and end up in wildlife, potentially accumulating to toxic levels.

But until now scientists had never studied the behavioural impacts of small quantities of contaminants. Tomas Brodin led a team that mimicked in the lab the concentrations of oxazepam found in the wild - around a microgram per kilogram of fish body weight - and watched for changes in how bold, sociable and active the fish were.

"Normally, perch are shy and hunt in schools," said Brodin. "This is a known strategy for survival and growth. But those who swim in oxazepam became considerably bolder."

Magnify

Researchers find new owl species in Indonesia

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© AFP Photo
Researchers in Indonesia unwittingly identified a new species of owl believed to be unique to the country, raising hopes of further new bird discoveries, a scientist said Thursday.

The brown-and-white Rinjani Scops owl was first spotted in 2003 on the island of Lombok, while researchers were looking for another nocturnal bird. It was formally identified by four scientists Wednesday in the online "Plos One" journal.

Prior to that, the bird had been mistaken for the related Moluccan Scops owl, found in the Maluku islands in central Indonesia.

"Ornithologists have long patted themselves on the back, believing that the taxonomy of birds was almost complete," researcher George Sangster from the Swedish Museum of Natural History, told AFP.