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Tue, 17 Jan 2017
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Mars

Giant 'wave' traversed Venus in December 2015 - Largest-ever observed in solar system

© Planet-C
The Japanese probe Akatsuki has observed a massive gravity wave in the atmosphere of Venus. This is not the first time such a wave was observed on the Solar System's second planet, but it is the largest ever recorded, stretching just over 6,000 miles from end to end. Its features also suggest that the dynamics of Venus' atmosphere are more complex than previously thought.

An atmospheric gravity wave is a ripple in the density of a planet's atmosphere, according to the European Space Agency. (This isn't a gravitational wave, which is a ripple in space-time.) We have these waves in Earth's atmosphere, too; they interfere with weather and cause turbulence. Scientists have observed atmospheric gravity waves on Venus before: the European Space Agency's Venus Express spotted several before the end of its mission in 2014. Since its initial observations, Akatsuki has spotted several smaller structures with its infrared cameras in April and May 2016.

Akatsuki spotted this particular gravity wave, described in a paper published today in Nature Geoscience, when the probe arrived at the planet on December 7th, 2015. The spacecraft then lost sight of it on December 12th, 2015, because of a change in Akatsuki's orbit. When the probe returned to a position to observe the bow-shaped structure on January 15th, 2016, the bright wave had vanished.

Comment: They don't actually know that it's a gravity wave, contrary to the certitude in the above article. From the New York Times:
In a paper published Monday by the journal Nature Geoscience, scientists working on the mission describe their observations in detail and suggest it was a "gravity wave" — a disturbance in the winds caused by the underlying topography that propagated upward.

The bow-shape arc appeared above Aphrodite Terra, a highland region about the size of Africa that rises up to three miles from the surface. Scientists working on data from the European Space Agency's Venus Express reported finding a similar disturbance in the atmosphere.

The authors of the new paper said that numerical simulations provided preliminary support for the idea, but that they still could not explain how the gravity wave forms and propagates in the lower atmosphere. Or why the prominent smile was seen in December 2015 and not since.

In October 2014, Comet Siding-Spring passed so close to Mars that it caused that planet's atmosphere to glow.

Also, sometime between 2012 and 2014, Mars acquired 400+ fresh meteor craters.

Back in March/April 2012, 'clouds' were spotted on Mars for the first time (in what 'should have been' an 'impossibility').

We don't know how this all connects, but we suggest that these events (and more besides) all indicate significant changes taking place at a solar system-wide level.


Magnify

Military spy laser concept aims to transform Earth's atmosphere into a giant magnifying glass to snoop on enemies

© BAE Systems
BAE Systems is working on a new type of directed energy laser and lens system, which could allow the military to spy on enemy activity, as well as form a 'deflector shield' to protect aircraft from enemy attacks
The idea of a laser that can turn Earth's atmosphere into a giant magnifying glass may sound like science fiction.

But engineers say that this could be a reality within the next 50 years.

BAE Systems has come up with a concept for a laser that creates structures in the Earth's atmosphere with similar properties to lenses.

This could help it spy on enemies as well as act as form a 'deflector shield' to protect aircraft from enemy attacks.

Windsock

George Will: "Academia may now be beyond satire"

Note to readers: This Sunday column by George Will appeared in my local newspaper this week, and I thought it relevant to repeat the headline and excerpts of it here, because what Will discusses is relevant to the fractured state of climate science. Peer review has turned into "pal review" due to the small population of qualified researchers in climate, and many of the same lessons taught by an exercise in taunting the peer review process in 1996 are germane to the publication of climate science today, where there seems to be an air of "anything goes as long as it goes with our thinking". On the opposite side, we have garbage papers accepted by people who transposed their names to get past what they feared would be gatekeeping.

Publishing a paper in a peer reviewed journal is by no means a guarantee of accuracy. Just look what happened to Eric Steig with his much ballyhooed front cover paper espousing warming in Antarctica in the world's most prestigious journal Nature, in 2009. Climate skeptics soon discovered that the warming in Antarctica was nothing more than a mathematical artifact of some shonky Mannian-style methodology (Michael Mann was a co-author), due to familiar problems Mann had with his hockey-stick methods, and the paper was quite rightly trounced by a rebuttal paper. But, it took a huge amount of work, ten months of peer-review, and the headlines that original flawed paper received still reverberate today.

Comment: Going back to 2007, and all but forgotten:

New Peer-Reviewed Study Finds 'Global Warming is naturally caused and shows no human influence'

For a different take on the issue of climate and other aspects of our world, have a read from Pierre Lescaudron (Author) and Laura Knight-Jadczyk (Contributor) book: Earth Changes and the Human Cosmic Connection: The Secret History of the World.

As for George Will, the Pulitzer Prize columnist (a little removed from the discussion of peer review), you can get a sense of where he is coming from with his college commencement speech, which was never heard on campus:

The speech every 2015 college grad needs to hear




Mars

The Search for DNA - On Mars

Astrobiologist alumna Alexandra Pontefract, PhD'13 (Geology), knows finding DNA on the Red Planet will be no easy feat. But it is possible. What's more, if DNA is found, it's not far-fetched to think it would be proof of shared ancestry between Earth and Mars.

"There is a really good argument for the fact that if there was life on Mars, it would have shared ancestry with Earth. That's because back towards the origins of the solar system, between 4.1 and 3.8 billion years ago, Earth and Mars had formed, and there is evidence they were both habitable at that point in time," said Pontefract.

"At the time, there was something going on called the Late Heavy Bombardment, and meant the inner solar system was being hit with lots and lots of meteorites. There was a big exchange of rocks between Mars and Earth. There have been studies that have shown biology can survive being ejected from a planet and survive in space. We know it's possible; it's really amazing."

Satellite

SpaceX successfully lands Falcon 9 rocket after carrying 10 iridium satellites into orbit

© Gene Blevins / Reuters
SpaceX Falcon rocket lifts off from Space Launch Complex 4E at Vandenberg Air Force Base, California, U.S., January 14, 2017
SpaceX has successfully landed its Falcon 9 rocket after delivering a payload of millions of dollars worth of satellites into orbit, less than four months after a similar mission was scuppered by a fiery explosion.

Consistently sending hardware into orbit is one of the chief goals of Elon Musk's SpaceX, but Saturday's launch was the first delivery mission since August 30 when things went pear-shaped.

In the first stage of Saturday's mission to and from low orbit, the Falcon 9 successfully carried a payload of 10 Iridium satellites into space from Vandenberg Air Base, California.

The reusable rocket then made a safe landing to the Pacific Ocean droneship, 'Just Read the Instructions.'

Rose

Plant sense: Perceiving the world without eyes, ears or brains

© Igor Stevanovic/Alamy
What do these sunflowers "know"? (
Plants perceive the world without eyes, ears or brains. Understanding how can teach us a lot about them, and potentially a lot about us as well

Plants, according to Jack C Schultz, "are just very slow animals".

This is not a misunderstanding of basic biology. Schultz is a professor in the Division of Plant Sciences at the University of Missouri in Columbia, and has spent four decades investigating the interactions between plants and insects. He knows his stuff.

Instead, he is making a point about common perceptions of our leafy cousins, which he feels are too often dismissed as part of the furniture. Plants fight for territory, seek out food, evade predators and trap prey. They are as alive as any animal, and - like animals - they exhibit behaviour.

"To see this, you just need to make a fast movie of a growing plant - then it will behave like an animal," enthuses Olivier Hamant, a plant scientist at the University of Lyon, France. Indeed, a time-lapse camera reveals the alien world of plant behaviour in all its glory, as anyone who has seen the famous woodland sequence from David Attenborough's Life series can attest.

Comment: Read more about plants' surprising complexity:


Snowflake Cold

Physicists able to 'squeeze' light to cool microscopic drum below quantum limit

© Teufel/NIST
NIST researchers applied a special form of microwave light to cool a microscopic aluminum drum to an energy level below the generally accepted limit, to just one fifth of a single quantum of energy. The drum, which is 20 micrometers in diameter and 100 nanometers thick, beat 10 million times per second while its range of motion fell to nearly zero.
Physicists at the National Institute of Standards and Technology (NIST) have cooled a mechanical object to a temperature lower than previously thought possible, below the so-called "quantum limit."

The new NIST theory and experiments, described in the Jan. 12, 2017, issue of Nature, showed that a microscopic mechanical drum -- a vibrating aluminum membrane -- could be cooled to less than one-fifth of a single quantum, or packet of energy, lower than ordinarily predicted by quantum physics. The new technique theoretically could be used to cool objects to absolute zero, the temperature at which matter is devoid of nearly all energy and motion, NIST scientists said.

"The colder you can get the drum, the better it is for any application," said NIST physicist John Teufel, who led the experiment. "Sensors would become more sensitive. You can store information longer. If you were using it in a quantum computer, then you would compute without distortion, and you would actually get the answer you want."

"The results were a complete surprise to experts in the field," Teufel's group leader and co-author José Aumentado said. "It's a very elegant experiment that will certainly have a lot of impact."

The drum, 20 micrometers in diameter and 100 nanometers thick, is embedded in a superconducting circuit designed so that the drum motion influences the microwaves bouncing inside a hollow enclosure known as an electromagnetic cavity. Microwaves are a form of electromagnetic radiation, so they are in effect a form of invisible light, with a longer wavelength and lower frequency than visible light.

The microwave light inside the cavity changes its frequency as needed to match the frequency at which the cavity naturally resonates, or vibrates. This is the cavity's natural "tone," analogous to the musical pitch that a water-filled glass will sound when its rim is rubbed with a finger or its side is struck with a spoon.

NIST scientists previously cooled the quantum drum to its lowest-energy "ground state," or one-third of one quantum. They used a technique called sideband cooling, which involves applying a microwave tone to the circuit at a frequency below the cavity's resonance. This tone drives electrical charge in the circuit to make the drum beat. The drumbeats generate light particles, or photons, which naturally match the higher resonance frequency of the cavity. These photons leak out of the cavity as it fills up. Each departing photon takes with it one mechanical unit of energy -- one phonon -- from the drum's motion. This is the same idea as laser cooling of individual atoms, first demonstrated at NIST in 1978 and now widely used in applications such atomic clocks.

The latest NIST experiment adds a novel twist -- the use of "squeezed light" to drive the drum circuit. Squeezing is a quantum mechanical concept in which noise, or unwanted fluctuations, is moved from a useful property of the light to another aspect that doesn't affect the experiment. These quantum fluctuations limit the lowest temperatures that can be reached with conventional cooling techniques. The NIST team used a special circuit to generate microwave photons that were purified or stripped of intensity fluctuations, which reduced inadvertent heating of the drum.

Comment: See also: Physicists Squeeze Light To Quantum Limit


Better Earth

New expedition to probe Mariana trench's deepest secrets

© NOAA Office of Ocean Exploration and Research
The remotely operated vehicle Deep Discoverer exploring the Mariana Trench at a depth of 6000 meters in 2016. A new effort aims to understand the trench's unusual geodynamics.
The Mariana Trench "is a little crazy," Jian Lin says. The scythe-shaped cleft in the western Pacific sea floor, 2550 kilometers long, plunges nearly 11 kilometers, deeper than any other place in the oceans. But what wows Lin, a marine geophysicist at the Woods Hole Oceanographic Institution in Massachusetts, is the zany topography. The trench marks a subduction zone, where one slab of crust slides beneath another. But whereas many other subducting plates slope gradually downward, in the Mariana the Pacific Plate dives nearly vertically.

Scientists have long wondered what accounts for that precipitous dive, and why the massive earthquakes that generate long-ranging tsunamis at other subduction zones have not been recorded in the trench. Now, a Chinese-U.S. team has planted an array of seismometers on the Mariana's slopes. By listening for seismic waves, says Lin, a project co-leader, the 5-year, $12 million Mariana Trench initiative aims to image in fine detail the warped rock layers in and around the trench, looking for clues as to what shapes them.

Comment: See also:

Scientists may have identified mysterious, metallic sound coming from the Mariana Trench
Deep-sea audio recordings reveal Pacific Ocean's noisy Mariana Trench, surprising scientists
Researchers find microbial life at the bottom of the Mariana Trench


Evil Rays

Amazon seeking permission to run experimental wireless technology tests in rural Washington

© Getty / Drew Angerer
Amazon CEO Jeff Bezos.
Amazon is preparing to test experimental wireless communications technology, including mobile devices and fixed-base stations, in rural Washington and Seattle, the company disclosed in government filings this week.

The filings do not specify what the tests would be for, but they hint at a new type of technology or wireless service, noting that the project would involve prototypes designed to support "innovative communications capabilities and functionalities."

Even more intriguing is that Amazon listed Neil Woodward as the main contact on the filings. Woodward, a retired NASA astronaut who joined Amazon in 2008, is now a senior manager for Prime Air, the team in charge of Amazon's drone-delivery effort, according to his LinkedIn page.

That suggests the tests could involve some kind of communications system to control Amazon's delivery drones. But the details in the filings could also point to a wireless service designed to work with mobile handsets, such as Amazon's Kindle tablets, or perhaps the Echo home speakers that Amazon sells.

Comment: Further reading:


Galaxy

Mystery object spotted in Cygnus A Galaxy

Astronomers have discovered an object in the active galaxy Cygnus A that wasn't there before.

© NRAO/AUI
The galaxy Cygnus A "shines" in radio frequencies (seen here), coming from relativistic electrons zipping along jets shot out from the central black hole and deposited in giant "radio lobes." (The lobes extend outward roughly 10 times farther than the galaxy itself, which is invisible in this image.)
Last week at the American Astronomical Society meeting in Grapevine, Texas, astronomers made an announcement that's caught the interest of several researchers: a very bright something has appeared in a well-known galaxy.

That galaxy is the elliptical Cygnus A. Cygnus A is one of the brightest radio sources in the sky. It lies approximately 800 million light-years from us (redshift of 0.056). In its core sits a supermassive black hole madly eating and cocooned in gas, while two jets shoot out to either side and light up the intergalactic medium. This activity produces the radio radiation that makes Cygnus A so bright.

Using the recently upgraded Karl G. Jansky Very Large Array (VLA) in New Mexico, Rick Perley (NRAO) and colleagues took a gander at Cygnus A — the first time the instrument has looked at the galaxy since 1989. (Apparently astronomers spent so much VLA time observing the galaxy in the 1980s that they didn't feel the need to look again, Perley joked January 6th in his AAS presentation.) The new observations showed a surprise: a new, secondary object just southwest of the central black hole. This object wasn't in the 1989 radio image. Additional, higher-resolution observations with the Very Long Baseline Array also picked up the object, clearly distinct from the galaxy's nucleus. It's roughly 1,300 light-years from the center.

The whatever-it-is is about twice as bright as the brightest known supernova at these frequencies. In fact, it's much brighter than just about any transitory radio signal known, except for accreting supermassive black holes and tidal disruption events, outbursts created when a black hole eats a star.

The team scoured other archives and found the object in 2003 Keck infrared observations and, more iffily, in some images from Hubble. (The object is so red that it doesn't show up well at optical wavelengths, and in this range the space telescope's resolution isn't as good as that of Keck's adaptive optics.)