Discoveries
Has the day shortened because of the Chile earthquake? NASA seems to think so. (NEWSCOM)
Chile earthquake shortened Earth's day? NASA thinks so.
Earth's days may have gotten a little bit shorter since the massive earthquake in Chile, but don't feel bad if you haven't noticed.
The difference would be only about one-millionth of a second.
Richard Gross, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and colleagues calculated that Saturday's quake shortened the day by 1.26 microseconds. A microsecond is one-millionth of a second.
IN PICTURES: Images from the magnitude-8.8 earthquake in Chile
The length of a day is the time it takes for the planet to complete one rotation — 86,400 seconds or 24 hours.
An earthquake can make Earth rotate faster by nudging some of its mass closer to the planet's axis, just as ice skaters can speed up their spins by pulling in their arms. Conversely, a quake can slow the rotation and lengthen the day if it redistributes mass away from that axis, Gross said Tuesday.
Gross said the calculated changes in length of the day are permanent. So a bunch of big quakes could add up to make the day shorter, "but these changes are very, very small."
So small, in fact, that scientists can't record them directly. Gross said actual observations of the length of the day are accurate to five-millionths of a second. His estimate of the effect of the Chile quake is only a quarter of that span.
"I'll certainly look at the observations when they come in," Gross said, but "I doubt I'll see anything."
IN PICTURES: Images from the magnitude-8.8 earthquake in Chile
The common fangtooth, Anoplogaster cornuta, is a deep sea fish like the blobfish, but has some of the largest teeth in the ocean. (Newscom)
Move over blobfish, the fangtooth is scarier
Last week a Chicago Tribune columnist opined that the "blobfish" is scarier than the Asian carp because of its potential to swim up rivers and ooze from your shower head.
No doubt that's frightening. But scarier than the fangtooth?
Blobfish? Pshah!
At least the blobfish has a human face. It's actually quite cuddly compared to the common fangtooth.
This one (photo above) looks like it could devour a goat in less than a minute. Maybe it could -- if it could find a goat. But where it lives, no goats roam. The fangtooth lives deep in the ocean depths. And it's got the largest teeth of any ocean fish proportionate to its size.
PHOTO GALLERY: The top 20 weirdest fish in the ocean
The front two fangs are so large that to close its jaws the fish has sockets for the teeth in the roof of its mouth.
Okay, so the fangtooth does only grow to be about six inches. But these guys, like piranhas, can travel in schools. Think packs of dracula fish.
Tempting fate?
Adult fangtooths typically feed on fish and are harmless to humans. So are sharks, relatively speaking.
Sharks sometimes confuse humans as prey, thinking our bodies look like a ready-made seal dinner. Who's to say the fangtooth won't confuse a human foot kicking gracefully for some sort of fish?
Well, you'd have to be a real deep swimmer. Fangtooths live in the pitch black dark of the ocean, about 3,000 feet to 16,000 feet down.
According to Extreme Science, 'They don't have any special lights or lures like the viper fish, so they move about 'blindly' in the darkness of the deep sea, basically grabbing onto whatever they run into in the dark - even if it's bigger than they are!'
As Marlin from 'Finding Nemo' said, 'Good feelings gone.'
PHOTO GALLERY: The 20 weirdest fish in the ocean
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Here's the mix of galaxy types in the local universe -- corresponding to the universe roughly at its current 13.8 billion-year-old age. The mix: 72 percent spirals, like the Milky Way; 15 percent spiral-elliptical hybrids; 10 percent "peculiar"; and 3 percent elliptical. But, six billion years ago... (next image, if you please) (Credit: NASA, ESA, Sloan Digital Sky Survey, R. Delgado-Serrano and F. Hammer (Observatoire de Paris))
Too early for Census results? Not if you're interested in galaxies!
The past six billion years of the universe's 13.8-billion-year history may have been more exciting than people thought.
If an international team of astronomers is correct, galaxy collisions and mergers happened far more frequently during that period than previous research has indicated.
The team, led by Paris Observatory astronomer Francois Hammer, found that 6 billion years ago, the universe contained far more "peculiar" galaxy shapes than appear in more recent times. In effect, the population of these oddballs declined at the same time the proportion of spiral galaxies like the Milky Way increased significantly.
The farther out in space you look, the older the objects are, because light travels at a constant speed. The team based its results on images of 148 galaxies whose distances correspond to the universe as it was about 6 billion years ago. And the group examined images of 116 local galaxies. The images the astronomers used to came from the Sloan Digital Sky Survey and NASA's Great Observatories Origins Deep Survey.
The results: Some 6 billion years ago, peculiar-shaped galaxies held the majority, at some 52 percent of the galaxy types in the sample. Spirals accounted for only 31 percent. Today, spirals make up some 72 percent of the sample, versus 10 percent for the peculiars. The proportion of the population in each sample accounted for by elliptical galaxies and spiral-elliptical hybrids remained virtually constant.
The dramatic drop in the number of peculiar galaxies was a surprise, according to Rodney Delgado-Serrano, a member of the team and the lead author of one of two papers reporting the results in a recent issue of the journal Astronomy and Astrophysics. You can find a plain-English version of the results here.
The results not only suggest that mergers and collisions, which would have led to the cosmic population shift, occurred more frequently more recently than previously thought. It also suggests mergers between peculiars and spirals – if both parties are rich in the gases from which stars form – appear to lead to the formation of large spiral galaxies, rather than ellipticals. In effect the disrupted disk rebuilds itself around its nucleus. That could be one reason why the local universe hosts so many spirals, the team suggests.
X marks the (moving) spot: NASA's Hubble Space Telescope has captured what astronomers are suggesting is a debris tail that formed from a recent collision between two asteroids. When the image was taken, the tail was 90 million miles from Earth and some 100 million miles from the sun. (NASA, ESA, and D. Jewitt (UCLA))
Has the Hubble Space Telescope spied asteroid-on-asteroid collision debris?
Astronomers appear to have offered iron-clad proof that two asteroids cannot occupy the same spot simultaneously.
That was never really in doubt, of course. But when you can grab an image of what appears to be fresh collision debris, it makes for an "oh, wow" moment.
Astronomer David Jewitt enlisted the help of the Hubble Space Telescope to observe the apparent collision debris -- a feature first detected in early January by the Lincoln Near-Earth Asteroid Research effort. (The US Air Force foots the bill for LINEAR, which is operated by MIT's Lincoln Laboratory in Lexington, Mass.) If Dr. Jewitt's interpretation holds up, it represents the first time astronomers have seen such a collision, or at least the recent aftermath of a collision.
The aftermath of ancient collisions? You can see it on very dark evenings in a feature called zodiacal light. The sun's rays bounce of space dust that appears along the orbital plane of the solar system's planets and contains tiny fragments from comets and from asteroid collisions. (For classic-rock fans, Queen lead guitarist Brian May finally got his PhD in astrophysics in 2007 on the strength of his studies of zodiacal dust.)
The new feature, dubbed P/2010 A2, looks a lot like a comet's tail, acknowledges Jewitt, a researcher at the University of California at Los Angeles. But it displays striking differences as well.
In effect, it's a headless tail -- it has no relatively uniform halo, or "coma," of dust at the leading end. The remains of the one of the asteroids -- now a kind of nucleus -- appears outside the halo, rather than inside. And spectroscopic studies using ground-based telescopes reveal no gases. Comets, on the other hand, spew copious amounts of gas as they approach the sun and the ices they contain turn from ice to a gas in a flash (do not pass liquid phase, do not collect $200).
Finally, Jewitt points out, the feature is orbiting the sun just inside the inner boundary of the main asteroid belt, between Mars and Jupiter.
Such collisions are very rare events within the life span of an astronomer. But over longer time spans? The two victims of this collision are believed to belong to a family of asteroids, touchingly named the Flora family. Astronomers trace this group's origin to a larger collision some 100 million years ago.
For all the asteroid belts sci-fi movies serve up -- densely packed obstacle courses that white-knuckled rocket jockeys try to negotiate -- our solar system's main asteroid belt is so diaphanous that you have to intentionally aim a spacecraft at one to stand a high chance of hitting it.
A little math with some very crude assumptions -- like a perfectly flat asteroid belt, and an even distribution of asteroids, among others -- helps make the point (bear with me here). By some estimates, there are some 1.7 million objects in the asteroid belt at least 1 kilometer (0.62 miles) across. So let's just go for the big ones.
The highest concentration of asteroids falls within a swath of space ranging from 2.1 and 3.3 astronomical units (AU) from the sun. So that band comprises an area of roughly 20 square AU. One AU, the average distance between the Earth and sun, is about 93,000,000 miles. Take the math all the way to the end, and you get one asteroid in that size class for every 102 billion square miles -- or only one kilometer-plus-sized rock for every imaginary box nearly 320,000 miles on a side.
Lots of room to miss.
Jewelry: so easy a cave man can do it
Move over Tiffanys. It seems even a Neanderthal can make jewelry. The right shells, a little pigment, and, voilà, shell beads.
A team led by University of Bristol archaeologist João Zilhão has uncovered what it interprets as evidence that Neanderthals made rudimentary jewelery from sea shells and pigments – up to now a level of symbolic art associated with early modern humans. Many have held that Neanderthals were too mentally primitive to develop symbolic art before they vanished from the scene.
The team reports that it found several examples, all of which date to about 50,000 ago. The dating is important, the researchers say. Other workers have found what they claimed was evidence of Neanderthal adornment. But those finds were roughly 40,000 years old – dating to a period where Neanderthals and modern humans would have shared the European continent. This has led other researchers to argue that the purported Neanderthal artifacts represented mindless imitation or were from later periods, but they somehow got mixed into the wrong soil layers of the archaeological digs where they were uncovered. These latest artifacts, however, date to a time before modern humans arrived, the team reports.
They team says it found several similarities between the sites where symbolic art – again, body adornments – as appeared among early-modern humans and Neanderthals. In both cases, the sites were near ancient shorelines, where shells would have been abundant. And the sites are at relatively high elevations compared with the shorelines of the day. So whatever poked holes in the shells to be worn, it is highly unlikely that the holes came from wind and wave processes or from the actions of animals.
At one of the two sites the team worked, the artifacts are associated with a time when Neanderthals had all but vanished. So those don't dodge the overlap argument critics ave leveled at other finds. The second batch of artifacts, however, came from deposits dated to 50,000 years ago. "The association of this material with the Neanderthals is, literally, rock solid," the team writes in presenting its results in the upcoming issue of the Proceedings of the National Academy of Science.
In trying to piece together the story of humans' intellectual evolution, the team concludes, their finds add weight to the argument that modern anatomy and modern behavior do not necessarily go hand in hand. The emergence of modern behavior s more likely caused by a combination of technological development, population increases, and increasing social complexity.
Three-year-old Audrey Carson of Omaha samples unusually early snow in Omaha, Neb., Saturday, Oct. 10, 2009. Several inches of snow accumulated in Omaha. (Nati Harnik/AP)
Biggest news you've never heard: Earth isn't warming
How do you reconcile the early snow in Minneapolis, ski resorts already opening in Nevada, and that August chill in North Dakota with expert warnings about a warming climate?
You don’t. Why? The Earth isn’t warming right now, is why. It may even be cooling down somewhat.
Five major climate centers around the world agree that average global temperatures have not risen in the past 11 years, according to the BBC. In fact, in eight of those years, global average temperatures dipped a tad.
Yes, there have been several record heat spikes during that time period. The Southern Hemisphere this summer saw the highest land and water temperatures ever recorded, for instance. But overall? Steady as she goes.
Reasons cited range from a slightly cooling Pacific -- a major global heat trap -- as well as renewed questions about the sun’s role in warming (about which there is much debate). Also, it’s possible, some say, that warming itself causes CO2 levels -- which are associated with warming -- instead of the other way around.
As a result, “The depth of the cold of the coming winters will change the social and political climate in ways that only nature can orchestrate,” predicts meteorologist Art Horn.
To be sure, it’s way too early to close one’s ears to those who predict more global warming and sea level rises. The UN's climate agency predicts that from 2010 to 2015 at least half the years will be hotter than the current hottest year on record, which was 1998. And as most of us know, the Earth warmed at historic rates in the latter half of the 20th century, leading to ice cap melts and ecological implications around the globe.
But the warming stall, some experts say, is giving at least some credence to the contrarian (and not always scientifically sound) notion that it may be natural and solar forces contributing as much, or more, than man-made CO2. At the very least, a delay in warming even as total CO2 emissions increase, throws some doubt on the cause-and-effect relationship between mankind’s activities and mean global temperatures.
Climate specialists say their models incorporate all this, and insist their predictions for continued warming will still hold true. (Here’s some data from the Guardian about why the “global warming is taking a break” theme may be off-base.)
Meteorologists at the UK’s Hadley Centre, for instance, point out that global temperatures aren’t linear, and that all data sets -- including solar phenomenon and ocean temperatures -- indicate that warming will soon pick up again.
But as Paul Hudson, the BBC’s environment reporter, points out, Mojib Latif, a member of the UN’s Intergovernmental Panel on Climate Change, agrees that the Earth may, in fact, continue to cool for another 10 to 20 years. Mr. Latif says that doesn’t make him a climate change skeptic, just a scientist. Eventually, he says, “the overwhelming force of man-made global warming reasserts itself,” according to the BBC.
Obviously, climate change has global ecological and political implications. The cap-and-trade bill and new auto emissions rules in the US are direct responses to climate implications of CO2. December’s Copenhagen climate conference will try to seek renewed global commitment to CO2 reduction.
Taken together, what does it all mean?
“Climate change -- no matter how benign or severe a course it takes -- makes legislating during the 21st century one of the most complicated and complex tasks for elected officials in human history,” writes Morgan Josey Glover in the Greensboro, N.C., News-Record newspaper.
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Artist's impression of LCROSS watching the Centaur upper stage it guided smash into the moon. After the first collision, the instruments on LCROSS will measure the properties of the material the collision kicks up. Then it too smacks into the moon. (Reuters)
NASA moon bombing successful. Did we find water?
NASA did it. NASA bombed the moon.
Its LCROSS mission punched two new craters in the moon this morning, and only about a minute behind schedule (see video below).
As for whether LCROSS kicked up evidence for water on the moon (the object of the exercise), the jury is still out.
It will take scientists a couple of weeks to figure out if the shadowed area of Cabeus crater holds any water ice. Visually, not much seemed to happen. Michael Bicay, the science director a NASA's Ames Research Center said: "It's hard to tell what we saw here."
But if the science team does find water? How do you get at it, especially if it's covered with moon dust? Just nuke it in a microwave!
That's an approach Ed Ethridge and his colleagues are experimenting with at NASA's Marshall Space Flight Center in Hunstville, Ala. It's a way of turning radio waves into a wringer.
Using simulated moon dirt, they found that under very cold, moon-like temperatures and in a vacuum, a standard household microwave oven would heat the lunar soil, causing ice that had condensed on the soil's grains to change directly from solid directly to gas. By trapping and cooling the gas, they got liquid water.
The approach clearly isn't ready for prime time, Dr. Ethridge cautioned during a phone chat. But it is a proof of principle, he says.
If it works on real lunar soil, it could eliminate the need to dig up icy soil with heavy machinery and run it through energy-hunger water-removal equipment.
Typically, when you cook with a microwave, he says, the microwaves are heating up the water molecules in the food -- cooking from the inside out. But heating ice itself is a different issue. Take that frozen chicken you defrosted as an example. It took several minutes. That's because the oven is operating at less than full power. But it also takes time because ice doesn't respond to microwaves as readily as liquid water does, Ethridge explains.
In the case of lunar soil, the microwaves heated it just enough, even at liquid-nitrogen temperatures, to warm the ice, which then vaporized.
Dr. Etheridge's team extracted 99 percent of the simulated soil's water content.
With data from the experiment well in hand, Ethridge says his group wants to measure the properties of true lunar soil archived at the Johnson Space Center. Then the team can plug that information into their computer models to gage how lunar soil would respond to microwaves.
Lunar-outpost designs call for recycling virtually everything possible, Ethridge notes. But those designs still envision loses -- to the tune of about a ton of water and a ton of oxygen a year.
If microwaving lunar soil proves practical, it could provide a relatively simple way to replenish those losses. And, he adds, "we wouldn't have to strip-mine the moon to do it."
Asteroid 'Apophis' will miss us this time; but 2068? Stay tuned
The asteroid Apophis is very unlikely to smack Earth in 2036. That's the good news from a large group of planetary scientists meeting this week in Puerto Rico (nice gig if you can get it!).
Astronomers discovered the asteroid in 2004. At the time, it looked as if it had a 2.7 percent chance of hitting us in 2029. Additional tracking enabled scientists to refine their calculations of the asteroid's orbit. Those calculations ruled out a smack-down in 2029, but left Apophis with a 1 in 45,000 chance of connecting with Earth in 2036.
New numbers released yesterday, however, now put the odds for an impact in 2036 at 1 in 250,000. As astronomers continue to track the asteroid, they say they expect the odds to shrink further.
At some 0.27 kilometers (about 0.2 miles) across, the object would be capable of widespread destruction on a regional scale, according to calculations made by scientists at the Sandia National Laboratory in Albuquerque, N.M.
"The refined orbital determination further reinforces that Apophis is an asteroid we can look to as an opportunity for exciting science and not something that should be feared," notes Don Yeomans, who heads the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
What about 2068? Astronomers are now keeping a close eye on the asteroid for any potential 2068 encounter. At the moment, they're giving it one chance in 3 million of nicking the third rock from the sun.
But University of Hawaii astronomer David Tholen says there's an interesting difference in the 2068 encounter.
To understand that difference, journey with me if you will to William Tell's archery range. We have an apple, and in lieu of a youngster's head to mount it on, we'll imagine it sitting somewhere in front of a target with its colorful concentric rings.
The likelihood that an arrow will hit the bulls-eye and split the apple depends on a couple of things: the accuracy of the archer's aim, and where the apple is located in relation to the bulls-eye.
In astronomical terms, the target and its rings represent what researchers call the uncertainty region. It's the circle in space where the asteroid is calculated to pass on a certain date and at a certain time, plus or minus a few target rings. That bit of slop-over exists because scientist may not have enough observations of the asteroid's travels across the sky to be able to shrink the uncertainty region.
If each new batch of observations and calculations put the Earth father and farther outside this region of uncertainty, the asteroid becomes a great night-time show for anyone with a telescope or set of binoculars.
But if additional calculations go the other way, pushing Earth into the uncertainty region, the probability of an unpleasant encounter starts to rise.
Based on what astronomers know now, "Earth is more nearly centered in the 2068 uncertainty region," Dr. Tholen explained in an email exchange. "So if further observations improve the orbit without changing it significantly, then the uncertainty region will shrink with Earth still inside it." If that's true, it could spell bad news for our planet's inhabitants.
When Apophis swings by in 2029, the earth's gravitational pull will significantly change the asteroid's orbit, he continues. "A tiny error in the orbit will get magnified a lot after 2029," he writes. "To know where it will be with reasonable accuracy in 2068, we need to know where it is now to incredibly high accuracy, and that's tough to do with only four years of observations."
For the record, Dr. Tholen and his colleagues made the observations on which Apophis's newest collision probabilities are based. And you can bet he and others will be doing more of the same. The next opportunity for observations comes next year, but only for a week because the asteroid is moving behind the sun. Conditions for observers get a bit easier in 2011, he writes.
In the end, many astronomers expect new observations to further reduce the likelihood of a 2068 encounter.
If you're interested in more information on near-Earth objects, visit the NEO page at NASA's Jet Propulsion Laboratory. You can check out projected close encounters for the next few months here.
The famed Sydney Opera House takes on an orange hue through the haze of dust that blew in from the outback on Wednesday. (Reuters)
Dust storm in Australia turns Sydney into Mars
When dust storms blow through Australia's outback, it's par for the course. When they turn Sydney into a Mars look-alike, it's time to sit up and take note.
A swath of eastern Australia labored Wednesday (Aussie time) under the worst dust storm in more than 70 years. Check out this photo gallery we put together.
Any way you look at it, the event is pretty extraordinary. According to Reuters, the storm carried an estimated 5 million tons of dust from the continent's interior to the east coast. A fair bit of that is priceless farm topsoil, according to the report. At one point, the storm was dumping an estimated 75,000 tons an hour into the Pacific off Sydney.
The country's eastern portion, particularly the farmland watered (at least at one time) by the Murray and Darling Rivers, is in its 12th year of severe drought. And forecasters say that it is likely to continue as El Nino strengthens through the rest of the year.
As for the virtually inevitable global-warming question: Researchers and forecasters are loathe to attribute any single storm to climate change. But the storm does represent one kind of weather phenomenon that is expected to become more frequent as the climate warms.
Once it's kicked up, the dust itself has effects on regional and local climate. The particles reflect sunlight back into space, cooling temperatures underneath it somewhat. Scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., published a study two years ago suggesting that dust-triggered cooling over the North Africa and the eastern Atlantic can affect sea-level air pressure and temperatures thousands of miles away. Others have noted that North African dust storms can retard hurricane formation in the Atlantic because its parasol effect keeps the ocean surface cooler than it might otherwise be.
Northeastern Asia, with dry regions such as the Gobi Desert, represent another big source of atmospheric dust. North Africa sends dust out across the Atlantic, over the Caribbean, and into the eastern Pacific Ocean. In the United States, the single largest source for mineral dust smaller than 10 microns is eastern California's Owens Lake, according to the US Geological Survey. Los Angeles emptied the lake, once criss-crossed by steamboats, during the first half of the 20th century.
In this photo released by Beluga Shipping on Friday, Sept. 11, 2009, a pair of German merchant ships are seen as they traverse the fabled Northeast Passage. Two German ships have traversed the fabled Northeast Passage, having arrived in Siberia from South Korea by traveling around Russia's Arctic coast line. Global warming and melting ice made the journey possible. (AP Photo/Beluga Shipping)
Arctic continues to skate on thin ice
The Arctic Ocean's summertime sea-ice melt season is ending, and the ice's expanse fell to the third lowest level since satellites began tracking sea-ice conditions in 1979.
Scientists with the National Snow and Ice Data Center in Boulder, Colo., noted this week that this year's retreat of summer sea ice was not as bad as last year's for two reasons: The summer there was cooler this year than last, especially so in a couple of specific regions; and wind patterns favored a smaller loss of summer ice.
Good news? Signs that global warming is over, if it ever was happening in the first place? Not so fast, scientists say. Yes, 2009 is shaping up to be the second year in a row where summer sea-ice extent has grown compared with the previous year -- following its satellite-record low in 2007. You can find the trends plotted on the second image in the series of images at the top of the page.
But before anyone breaks out the confetti or wags an I-told-you-so finger, the peak extent this summer is still some 24 percent below the 1997-2000 average. And it's 20 percent below the 1979-2008 average.
Moreover the ice that's there consists mostly of relatively thin ice rather than the thick multi-year ice that is less vulnerable to a complete meltdown during the summer. NASA's ICESat satellite has been tracking those trends. You can see the results in the third of the series of images at the top of the page.
Why does the ice matter? From a climate standpoint, all that white reflects sunlight back into space. If ice covers less ocean surface during the summer, the 24/7 sunlight heats more of the ocean. That heat content slows the return of ice in the fall and can continue to thin the remaining ice from underneath.
And while the water is exposed, the oceans warmth can take the chill off well inland (think about the Gulf Stream's moderating effect on temperatures during European winters). Researchers are increasingly concerned that this moderating effect from warmer coastal waters could reinforce the melting of permafrost on land, releasing methane -- molecule for molecule, a far more potent greenhouse gas than carbon dioxide.
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