- The Tsunami’s Ripple Effect
- Space Duct Tape Could Confuse Mars Rover
- Turn Your Cellphone Into a High-Powered Scientific Microscope
- Earthquake Is Biggest in Japan’s Recorded History
- Laser-Powered Tractor Beam Could Move Tiny Particles
- GOP Assault on Environment Defeated — For Now
- Best Mars Images From Orbiter’s First 5 Years
Posted: 12 Mar 2011 12:27 PM PST
I'm in southern South America preparing to lead a geological field trip and am just now catching up on the huge earthquake in Japan, the subsequent tsunami, and news about the devastation. My thoughts are with all the people directly affected by this disaster. There's obviously a lot of news out there to read about this event. Many of the geoscience bloggers are covering the geological aspects of this event — I don't have the time on this slow wi-fi connection to summarize it all so here are just a few:
Me and a couple colleagues have been down in this region for a few days checking out the outcrops and talking with locals to prepare for the trip. The participants are all arriving today and flying into the city of Punta Arenas, Chile, along the coast on the Strait of Magellan, which is where I sit right now. Earlier today there was talk of tsunami warning and potential evacuations but this has since been lifted. I don't know the details but am assuming a 'better safe than sorry' precaution was behind the alert. I'm all for that. I have no time for those who get upset about authorities "crying wolf" when it comes to this stuff.
What's amazing — and quite scary — is how much of the planet is affected by an event like this. Here I am at the southern tip of South America, more than 10,000 miles from the earthquake's epicenter, and we had to keep an eye on what was going on. Incredible.
Posted: 11 Mar 2011 02:02 PM PST
The NASA equivalent of duct tape could leak enough methane to confuse the next Mars rover's life-detecting sensors.
Astrobiologists found evidence for three distinct plumes of methane flowing from beneath the planet's surface, like swamp gas or a burp, in January 2009. The gas could simply mean that Mars is more geologically active than previously thought. But because much of Earth's methane is a byproduct of life, the plumes could point to something living, eating or breathing methane beneath the Martian surface.
To settle the question of the methane's origin, the next Mars rover, called Mars Science Laboratory or Curiosity, will launch in late 2011 equipped with a suite of instruments capable of sniffing out one molecule of methane in a billion other molecules.
But some of the materials in the rover itself could also release methane and confuse the sensors. In a paper in press in the journal Icarus, microbiologist and veteran Mars simulator Andrew Schuerger of the University of Florida and colleagues show that the tape used to hold the rover's joints together could release enough methane to be a problem.
"I think it's a valid concern,"said planetary scientist Adam Johnson of Indiana University, who has investigated which Earth microbes could hitchhike to Mars but was not involved in the new work. "We're sending a very very sensitive instrument, and we are able to produce concentrations of methane that are orders of magnitude above the detection limits for that instrument."
Schuerger and colleagues placed 18 materials in the Mars Simulation Chamber, a stainless steel cylinder whose interior mimics the atmosphere, dustiness, sunlight, temperature and pressure at the Martian surface.
"Andrew's simulation setup in his chamber is state of the art, the best simulation chamber in the world," Johnson said. "As far as simulation of the Mars conditions, you can't ask for much better."
The researchers tested a variety of biological materials, including amino acids, DNA and spores of a common soil-dwelling bacterium. They also checked several materials used to build the rover itself, including vacuum grease, a small sundial like the one rovers Spirit and Opportunity use to calibrate colored images, and kapton tape, the space industry equivalent of duct tape.
"I kind of think of it as electrical tape on Mars," Johnson said. "It's used for everything on there."
After eight hours in the chamber, all the organic materials tested emitted some amount of methane, though not enough to worry about in most cases. The methane comes from the interaction of sunlight with materials that contain a methyl group, one carbon atom attached to three hydrogen atoms. Ultraviolet radiation from the sun (or, in the simulation chamber, a special lamp) could rip methyl groups from the materials. The charged methyl groups could then steal an extra hydrogen atom from a neighboring molecule to form stable molecules of methane, which has one carbon and four hydrogens.
Surprisingly, the bacterial spores they tested leaked noticeable amounts of methane, even after they had been irradiated to death. But the standards for cleaning the rover before launch are so stringent that there probably won't be enough spores left on the rover by launch time to pose much of a problem.
The most trouble could come from kapton tape, which is ubiquitous and unavoidable on the rover. Schuerger's team found that in the first few Martian days of the mission, the sensors in Curiosity's Tunable Laser Spectrometer could pick up a few tens of methane molecules per million other molecules, about 100 times above the instrument's detection limits.
This is especially worrisome given that Curiosity uses about 3 square meters of kapton tape, more than any previous rover.
"It's a big monster rover," said NASA planetary scientist Paul Mahaffy, who is in charge of MSL's Sample Analysis at Mars (SAM) instrument. "They use the appropriate level of tape to secure that stuff down. There's just more of it than there might have been on [Spirit and Opportunity]."
The rover team already has a few low-tech solutions in mind to find the true Martian methane, Mahaffy said. First, they'll take measurements at night, when ultraviolet radiation will be at a low.
"My best guess is, once you rotate into the dark, methane production stops pretty fast," Mahaffy said. "By sampling at night we'd get a much cleaner sniff of the Martian atmosphere."
The rover will also rotate the sensors into the wind to get the strongest whiff of the Martian atmosphere. Schuerger and colleagues suggest coming up with more detailed models of how much methane kapton tape will produce, and where on the rover it's likely to show up. They also note that kapton tape gives off less and less methane as time goes on, so methane detections in the later parts of the mission should be more reliable.
"By no means does is nullify the measurement we're trying to do on [Mars Science Laboratory]," Mahaffy said.
Still, the study is "very useful," Mahaffy said. "It will help us do a better job of sorting out what's really there on Mars, and what we might bring along from Earth. The last thing we want to do is have a false positive."
Images: 1. Engineers assemble the Mars Science Laboratory ("Curiosity"), using rolls of shiny kapton tape. (NASA/JPL-Caltech) 2. The Mars Simulation Chamber. (Schuerger et al./Icarus)
Posted: 11 Mar 2011 10:14 AM PST
Using tape, rubber and a tiny glass ball, researchers transformed an iPhone into a cheap, yet powerful microscope able to image tiny blood cells. They've also added a clinical-grade cellphone spectroscope that might be able to measure some vital signs.
And with a few dollars and some patience, you can do the same to your own phone. (See instructions below.)
"It still amazes me how you can build near-research-grade instruments with cheap consumer electronics," said physicist Sebastian Wachsmann-Hogiu of the University of California at Davis, leader of a study March 2 in PLoS ONE. "And with cellphones, you can record and transmit data anywhere. In rural or remote areas, you could get a diagnosis from a professional pathologist halfway around the world."
Similar laboratory devices can cost thousands of dollars and be extremely bulky. Other researchers have created cellphone laboratory kits, but this new microscope is the most compact, simple and inexpensive design created so far. The team's other new device — a light-splitting spectrometer — looks crude but may have high enough resolution to measure blood oxygen levels, for example.
Electrical engineer Aydogan Ozcan of the University of California at Los Angeles, who helped develop an award-winning $10 microscope for cellphones, said the simplicity of the new prototypes is a big advantage.
"They're further miniaturizing this stuff. But we also need to focus on getting these innovative designs out in the field, tested, improved and saving the lives of people," said Ozcan, who wasn't involved in the new study. "In that sense, all of us working on this technology are in the same boat."
Two existing cellphone-microscope designs inspired the new iteration, including Ozcan's and another called CellScope, designed by bioengineer Daniel Fletcher at the University of California at Berkeley. Because both models protrude from the cellphone's camera and have several delicate parts, Wachsmann-Hogiu set out to create a simpler and more compact design.
The team tucked a 1-mm-wide glass ball into a ring of rubber and slipped it over iPhone and iPhone 4 cameras. The images are magnified 350 times, but have a very thin plane of focus. To combat the resulting blur, the team created software able to stitch the sharp parts together into one crisp photo. They also made a prototype cellphone spectrometer (based on a patent they found) using narrow PVC tubing, electrical tape and a special grating able to split light into its component colors.
It costs about $20 to create the microscope and a few dollars to make the spectrometer, but Wachsmann-Hogiu said costs could easily drop below $10 for both. The tiny lenses could be made out of plastic instead of glass, and economies of scale could eventually kick in.
The team is working on improving the imagery of their microscope prototype and giving it the capability to detect microbes by fluorescence. They're also building a phone-based app to stitch images together, count blood cells and determine blood oxygenation levels.
Ozcan said he looks forward to new consumer technology as an opportunity to make an even cheaper and more powerful laboratories-on-a-chip.
"There are dreamlike components in consumer electronics," Ozcan said. "It's orders of magnitude more amazing than the science community could have imagined just decades ago."
DIY instructions to turn your own cellphone into a microscope are below.
Image: Standard microscope images (top row) compared to a iPhone microscope images (bottom row). Sickle-cell anemia blood is at left, and crystals are at right. (PLoS ONE/Sebastian Wachsmann-Hogiu et al./Center for Biophotonics at the University of California at Davis)
Citation: "Cell-Phone-Based Platform for Biomedical Device Development and Education Applications." Zachary J. Smith, Kaiqin Chu, Alyssa R. Espenson, Mehdi Rahimzadeh, Amy Gryshuk, Marco Molinaro, Denis M. Dwyre, Stephen Lane, Dennis Matthews and Sebastian Wachsmann-Hogiu. PLoS ONE, Vol. 6, Issue 3. March 2, 2011. DOI: 10.1371/journal.pone.0017150
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Cellphone Microscope - Step 1
Grab any cellphone with a camera, but note models that use touchscreen focusing and/or have manual focus options are best.
Find some thin, dark, rubbery material and poke a small hole in it (less than 1 millimeter in diameter). This can be done using a pin or needle.
Image: Zach Smith/Kaiqin Chu/Sebastian Wachsmann-Hogiu. Instructions adapted from text by Zach Smith and Sebastian Wachsmann-Hogiu.
Posted: 11 Mar 2011 09:40 AM PST
The magnitude 8.9 quake that struck off Japan's coast on March 11 will go down as one of the country's largest earthquakes.
Even if its magnitude is downgraded in the coming days, as sometimes happens as more data are analyzed, the quake will remain a benchmark in a country that has seen many major quakes. It ranks fifth on the list of biggest quakes this past century. The Indonesian earthquake that spawned 2004's devastating Indian Ocean tsunami was a magnitude 9.1.
Japan's monster earthquake struck at 2:46 p.m. local time, about 150 km off the coast of the island of Honshu. Japan is one of the world's most prepared societies when it comes to earthquakes, and a recently established early warning system broadcast alerts in many areas, including Tokyo, before the shaking began.
Seismic activity in the region began with a magnitude 7.2 quake on March 3. Major aftershocks continue to rattle the area. The death toll is unknown.
Japan owes its lively seismic existence to its precarious geologic setting. The islands of Japan formed where one great plate of Earth's crust, the Pacific plate, dived beneath the Eurasian and Philippine plates. The collision is part of the "Ring of Fire" of earthquake and volcanic activity around the Pacific Ocean.
Chikyu, a deep-sea drilling vessel operated by the Japan Agency for Marine-Earth Science and Technology, is in the midst of a many-years study drilling into the seafloor off Japan's coast to study the genesis of big quakes there.
The deadliest quake in Japan's history came in 1923, when more than 140,000 people perished in the magnitude 7.9 Great Kanto Earthquake. That tremor was centered southwest of Tokyo Bay. The March 11 quake struck more to the north, offshore from the city of Sendai.
"Fortunately for Tokyo it's a bit further north than the great Kanto earthquake was, which means the damage in Tokyo is likely to be much less," Kevin McCue, a Canberra-based seismologist at CQUniversity in Australia, said in a statement.
Tsunami warnings spread across the Pacific in the hours after the earthquake; earthquakes generate tsunamis when the ground rupture displaces massive amounts of water. The size of the Japanese quake, plus its relatively shallow depth of 24 km, meant that it was primed to trigger tsunamis.
Honshu's east coast had essentially no time to prepare for the waves, but other locations around the Pacific set into gear preparation and evacuation plans polished after the 2004 Indian Ocean tsunami. Hawaii was reporting waves of 1 meter or less.
Japan Earthquakes Tsunami A computer model for the tsunami created by an 8.9-magnitude earthquake that struck 80 miles east of Honshu, Japan on March 11, 2011. Credit: NOAA/PMEL/Center for Tsunami Research
Image: A forecast for the tsunami caused by a magnitude-8.9 earthquake that struck off the coast of Japan on March 11, 2011. Heat-map colors show maximum tsunami height within the first 24 hours. (NOAA/PMEL/Center for Tsunami Research) [high-resolution version available]
Video: A computer model of tsunami propagation for the magnitude-8.9 earthquake that struck off the coast of Japan on March 11, 2011. (NOAA/PMEL/Center for Tsunami Research)
Posted: 10 Mar 2011 03:43 PM PST
Another piece of Star Trek technology has become a reality. Captain Kirk would instantly recognize new blueprints developed by a team of Chinese scientists as plans for a tractor beam.
The proposed device hasn't yet been built. But a similar one conceived by an American physicist was tested last year. Each device would fulfill the science fiction dream of reeling in objects using light — though neither could move anything bigger than a bacterium, much less a starship.
The Chinese plan, reported online Feb. 24 at arXiv.org, would use a laser to produce what is called a Bessel beam. This beam, unusual because it remains focused over large distances, could induce electric and magnetic fields in an object in its path. The spray of light scattered forward by these fields could push the object backward, against the movement of the beam itself. "This analysis established that light can indeed pull a particle…. Under appropriate conditions a [Bessel beam] can act as an 'optical tractor beam,'" write physicist Jun Chen of Fudan University in Shanghai and colleagues.
Physicist David Grier of New York University believes that the Chinese plan would work. And Grier should know: he designed his own tractor beam and built it, demonstrating for the first time that a beam of light can tug objects over long distances. His paper was published in the March 29, 2010, Optics Express.
"Both of these papers give us new tools," says Phil Jones, a physicist at University College London. "Something like this would have useful applications for moving particles. The effects are also quite size-dependent, so they might also be useful for sorting particles of different sizes."
A beam of light that can pull is counterintuitive to physicists, who have spent centuries studying light's ability to push.
"You normally think of light as being like a fire hose that just blows you downstream," says Grier. That's because when particles of light strike an object, they rebound like Ping-Pong balls and give a weak nudge. This radiation pressure is thought to shape the tails of comets and is useful for pushing solar sails in space.
The invention of the laser provided scientists with a stronger source of light and a push that could do useful work on Earth. Researchers now routinely use optical tweezers based on this push to pin down and manipulate atoms and small objects. But turning this push into a pull required more sophisticated optics — in Grier's case, a solenoid beam. Unlike traditional lasers, which are bright in the middle and dimmer at the edges, a solenoid beam contains a bright spiral of intense energy.
This corkscrew of energy tends to attract small spheres made of silica. The light in the corkscrew can then be tilted at an angle that kicks the spheres backward even as the beam itself moves forward. Like a tennis player sprinting away from the net while deftly lobbing the ball back at an opponent, this tilt can potentially push an object all the way back to the beam's source. Or it can be rotated to push forward. Switching between these states allows Grier to move objects back and forth.
The force of this push and pull, limited by the laser's strength and the speed of light, is small. But it's enough to tug 1.5-micrometer-wide spheres a distance of about eight micrometers — with much larger distances theoretically possible.
"You'd need a terawatt [or trillion-watt] laser to pull a person," says Grier. Being struck by that much energy, though, would likely incinerate the person being pulled. "It would be a short trip."
In a new paper to appear in an upcoming issue of Optics Express, Grier describes new schemes for his tractor beam that even Mr. Scott couldn't imagine. Instead of pulling objects along a simple straight line, Grier has begun to explore curves, loops and even knotted paths that cross themselves.
As a first demonstration, he guided spheres around ring-shaped tracks tilted in different three-dimensional orientations. This particle puppeteering, he says, could be useful in generating plasma currents to stabilize fusion power-generation technologies.
Video: Unlike traditional laser beams, solenoid beams in proposed tractor-beam devices contain a bright spiral of energy woven into their light. (David Grier/New York University/Science News/Vimeo)
Image: A new tractor-beam design tilts the angle of light within a laser beam to switch from pushing (left) to pulling (right) an object. Gray arrows show the angle of this tilt. Sang-Hyuk Lee, Yohai Roichman, and David G. Grier, "Optical solenoid beams," Opt. Express 18, 6988-6993 (2010)
Posted: 10 Mar 2011 12:50 PM PST
No limits on neurotoxic pollution by cement plants. No protecting endangered fish in San Francisco Bay. And no regulation of greenhouse gases.
Those are just some of the "riders" tacked onto HR1, the GOP spending bill defeated Wednesday in the Senate — but sure to return as Congress negotiates how the U.S. government will be supported.
The bill would have funded the government for the remainder of Fiscal Year 2011, which began last October and has been defined by the failure of Congress to agree on a budget.
As would be expected in any legislation this massive and urgent, HR1 contained hundreds of fine-print amendments that had little or nothing to do with federal spending, but reflected ideological wishes or political favors.
'This week's debate is just a dress rehearsal for the big stuff.'
David Goldston, the House Committee on Science chief of staff under President George W. Bush who now directs government affairs at the Natural Resources Defense Council, broke down how riders work after HR1 passed the House in February.
Many of the anti-environmental riders that passed after what Goldston called a "weeklong carnival of destruction on the House floor" were dropped from the original House plan. But more than a dozen remained.
Several would have ordered the Environmental Protection Agency not to fulfill its duty, legally mandated by Congress and the Supreme Court, to regulate greenhouse gas emissions. Other bills currently under consideration by Congress would do the same thing.
But the assault didn't stop there. HR1 would have cut the EPA's budget by nearly one-third. The agency would have been prevented from limiting pollution from a laundry list of neurotoxins and carcinogens — mercury, arsenic, PCBs, dioxins, heavy metals — at cement plants.
As Goldston recounts on an NRDC blog rundown of HR1's anti-environmental riders, the EPA estimates that cement plant restrictions would cost industry several hundred million dollars. In exchange, it would annually prevent 2,500 premature deaths, 1,500 heart attacks and 17,000 cases of asthma. Those public health benefits, or the cost of their absence, are worth between $6.5 billion and $17 billion.
The EPA would also have been blocked from updating its standards on soot pollution, which is responsible for up to half of current global-temperature increases. Neither would the agency be permitted to apply Clean Air Act standards to oil drilling in Alaska.
In California's San Francisco Bay and delta ecosystem, endangered fish would no longer be protected by the Endangered Species Act. (Ditto wolves in parts of the Rocky Mountains.) The proposed restoration of the San Joaquin River would be halted, as would cleanup efforts in Chesapeake Bay.
Under HR1, the Clean Water Act could no longer be used to restrict water pollution that killed wildlife. The EPA would have been prevented from developing handling procedures for coal ash, a carcinogen, and prevented from enforcing restrictions on mountaintop removal mining.
Even Rep. Joe Barton (R-Texas), best known for apologizing to BP during the Deepwater Horizon disaster, said the EPA-gutting was going too far. Scott Slesinger, the NRDC's legislative director, called HR1 "the most anti-environmental bill in 40 years."
The bill was defeated, 44-56, but its provisions are likely to return in other spending bills. As Mitch McConnell (R-Kentucky) said after HR1's Senate defeat, "This week's debate is just a dress rehearsal for the big stuff."
Images: 1) The former Holmes Road Incinerator in Houston. (Marc St. Gil/Documerica — a photography project commissioned by President Richard Nixon after the Environmental Protection Agency was established in 1970.) 2) Contaminated water in a ditch behind the Pittsburgh Glass Company. (Marc St. Gil)
Posted: 10 Mar 2011 12:49 PM PST
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NASA's prolific Mars Reconnaissance Orbiter turns five Earth years old Thursday.
Since settling into orbit around the Red Planet on March 10, 2006, MRO has transmitted more data to Earth -- 131 trillion bits and more than 70,000 images so far -- than all other interplanetary missions combined.
After the orbiter finished all its initial science objectives in the first two years, NASA extended its lifetime twice. The extra time let MRO watch Mars change over two-and-a-half Martian years, giving a new picture of a shifting, dynamic planet.
"Each Mars year is unique, and additional coverage gives us a better chance to understand the nature of changes in the atmosphere and on the surface," said Rich Zurek of NASA's Jet Propulsion Lab in a press release. "We have already learned that Mars is a more dynamic and diverse planet than what we knew five years ago. We continue to see new things."
MRO carries six science instruments, including radar that peels back the layers of the Martian surface, a spectrometer that has mapped the mineral content of three-quarters of the planet, and a weather camera that monitors clouds and dust storms.
But the show stopper is the HiRise camera (High Resolution Imaging Science Experiment), which can resolve features the size of a beach ball from 180 miles away.
To date, HiRise has snapped more than 18,500 close ups of Mars' canyons, craters and dunes. In honor of MRO's fifth birthday, here are some of our favorites.
These twisty trails were traced by dust devils, spinning columns of rising air that pick up loose red dust grains and reveal darker, heavier sand beneath. Dust devils have been blamed for unexpectedly cleaning off the Mars rovers' solar panels. This image was taken Aug. 24, 2009.
Images: NASA/JPL/University of Arizona
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