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n2doc's JournalLightning strikes produce free neutrons, and we're not sure how
By Chris Lee
For the last 30 years there has been a very small controversy rumbling in the hallowed halls of physics. Way back in 1985, scientists from the then-USSR noted that whenever a thunder storm passed over their neutron detector, they observed an increased flux of neutrons. Unfortunately, they didn't have much in the way of monitoring equipment to really nail down much beyond the initial observation.
Since then, scientists have put forward a couple of potential explanations for the observed flux. One was that the high fields generated during lightning strikes was modifying the trajectories of muons from cosmic ray showers. In short: these are cosmic rays, and this is not interesting. The second was that the gamma rays emitted during the lightning strike generated neutrons, a photonuclear event. But new measurements show that neither of these explanations can explain the data.
The (now) Russian scientists have designed an entirely new experiment that significantly improves their previous results. They installed three neutron detectors that were sensitive to low energy neutrons: one above ground, one partially shielded in a building, and a third underground with heavier shielding. Sitting next to the underground detector was a more traditional neutron detector that is sensitive to high energy neutrons. Finally, the electrical activity of incoming storms was monitored using a variety of instruments, allowing for better correlation between the neutron measurements and the electrical activity of any passing storms.
Why the variety of neutron detectors? Essentially, the researchers need to get rid of the background noise from cosmic rays. The cosmic rays generate muons that collide with something in or very near the detector, resulting in neutrons that have the high energy of the muon being registered. Neutrons from lightning, on the other hand, can only have the energy given up by a fission event, which is then lost in collisions with molecules in the air as they travel to the detector.
more
http://arstechnica.com/science/news/2012/03/nuclear-lightening.ars
Mystery Cloud Appears On Mars
Analysis by Irene Klotz
The amateur astronomy community is abuzz over a strange phenomenon spotted over Mars last week. Astrophotographer Wayne Jaeschke reports on his website of a "strange feature" over the Martian plain called Acidalia that moves with the planet and seems to rise over the limb.
The discovery has professional astronomers taking note. NASA's Mars Odyssey spacecraft will try to image the cloud with a camera that can take pictures in visible and infrared light simultaneously.
"Our atmospheric researchers are pretty excited about the possibility of not only getting a good look at the cloud structures, but also their temperatures," Arizona State University astronomer Jonathon Hill tells MSNBC.com.
Whatever it is -- or was -- the feature is diminishing in size.
"This has led some to believe that it was some sort of transient-type event," Jaeschke told MSNBC.
more
http://news.discovery.com/space/mystery-cloud-appears-on-mars-120326.html
'Giant Impact Theory' of Moon's Origin Modified
New research from geophysical scientist Junjun Zhang and colleagues at Origins Lab at the University of Chicago, suggests that the giant impact hypothes of the creation of the Moon might be wrong. The team found that in comparing titanium isotopes from both the moon and the Earth, that the match is too close to support the theory that the moon could have been made partly of material from another planet.
According to the giant impact hypothesis, there was once a Mars-sized body referred to as Theia orbiting in our solar system. Theia would have formed in about the same orbit as Earth, but about 60° ahead or behind. When the protoplanet had grown to be about the size of Mars, its size made it too heavy for its orbit to remain stable. As a result, its angular distance from Earth varied increasingly, until it finally it crashed into the Earth.
The collision would have occurred 4.533 billion years ago when Theia would have hit the Earth at an oblique angle, and destroyed itself in the process. Theia's mantle and a significant portion of the Earth's silicate mantle were thrust into space. The left over materials from Theia mixed with the materials from the Earth and eventually formed the Moon.
more
http://www.dailygalaxy.com/my_weblog/2012/03/new-evidence-nixes-giant-impact-theory-of-moons-origin.html
Extreme Water! Edges of Mercury's Poles May Harbor Water Ice
New evidence from the Messenger spacecraft orbiting Mercury hints that the tiny planet may be harboring water ice in some of its most extreme terrain. The Messenger spacecraft has found that bright radar spots previously detected by the Arecibo Observatory in Puerto Rico appear to be in permanent shadow, according to camera views from the probe's Mercury Dual Imaging System (MDIS).
"We've never had the imagery available before to see the surface where these radar-bright features are located," Nancy Chabot, an instrument scientist for MDIS at the Johns Hopkins University Applied Physics Laboratory, said in a statement. "MDIS images show that all the radar-bright features near Mercury's south pole are located in areas of permanent shadow, and near Mercury's north pole such deposits are also seen only in shadowed regions, results consistent with the water-ice hypothesis."
http://www.dailygalaxy.com/my_weblog/2012/03/extreme-water-edges-of-mercurys-poles-may-harbor-water-ice.html
GA Restaurant Apologizes For Chris Brown/Rihanna Black & Bleu Burger Special
Ugh, good morning: Georgia restaurant Chops & Hops ran a Black & Bleu Burger as their special on Friday, but for some reason decided to dedicate the "celebrity sandwich" to Chris Brown and Rihanna. You know, because Brown was arrested for physically assaulting Rihanna the night before the 2009 Grammys. Oh, and they had this to add: "Chris Brown won't beat you up for eating this unless your name starts with a R and ends with A." Well, that's charming.
So, the restaurant has since apologized and will be donating a sum to domestic violence prevention/advocacy group Project Safe:
We have been involved in fundraising for Project Safe Team 6 and we fully intend on donating proceeds (times 6 - in honor of Team 6) from the sales of the burger. C&H continues to strive for a community driven, family oriented, great food and great service environment. We will continue to be involved in our community fundraising and charities near and dear to our hearts.
If they realize it's not a joke then why were they, um, joking about it? Anyway, since the burger was just a special on Friday it's no longer on the menu.
http://eater.com/archives/2012/03/26/ga-restaurant-apologizes-for-chris-brownrihanna-black-bleu-burger-special.php
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