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Showing posts from January 22, 2013

Comet of the Century?

Jan. 18, 2013: Out near the orbit of Jupiter, a faint speck of light is moving through the black of space. At first glance it doesn't look like much, no brighter than a thousand distant stars speckling the velvet sky behind it; indeed, it takes a big telescope make out that it is a comet. But what a comet it could turn out to be…. Later this year, “Comet ISON” could blossom into a striking naked eye object visible even in broad daylight. “Comet ISON is a sungrazer,” explains Karl Battams of the Naval Research Lab. “The orbit of the comet will bring it very close to the sun, which we know can be a spectacular thing.” A new ScienceCast video explores what could happen to Comet ISON as it approaches the sun in Nov. 2013. Possibilities range from "Comet of the Century" to "disintegrated dud." Play it Russian astronomers Vitali Nevski and Artyom Novichonok found the comet in Sept. 2012. It bears the name of their night-sky survey program, the International Scienti...

Solar Variability and Terrestrial Climate

In the galactic scheme of things, the Sun is a remarkably constant star. While some stars exhibit dramatic pulsations, wildly yo-yoing in size and brightness, and sometimes even exploding, the luminosity of our own sun varies a measly 0.1% over the course of the 11-year solar cycle. There is, however, a dawning realization among researchers that even these apparently tiny variations can have a significant effect on terrestrial climate. A new report issued by the National Research Council (NRC), "The Effects of Solar Variability on Earth's Climate," lays out some of the surprisingly complex ways that solar activity can make itself felt on our planet. These six extreme UV images of the sun, taken by NASA's Solar Dynamics Observatory, track the rising level of solar activity as the sun ascends toward the peak of the latest 11-year sunspot cycle. More Understanding the sun-climate connection requires a breadth of expertise in fields such as plasma physics, solar ...

French and Malian troops enter Diabaly

French and Malian troops take two key towns with little resistance as troops from Chad arrive in Mali French and Malian troops have entered the key central Malian towns of Diabaly and Doutenza, both of which have been in the hands of al-Qaeda-linked rebels for weeks. A convoy of about 30 armoured vehicles carrying about 200 French and Malian soldiers moved into the town on Monday at about 09:00 GMT, without meeting resistance. Diabaly, 350km north of the capital Bamako, had harboured the main cluster of rebels south of the frontline towns of Mopti and Sevare until French air attacks forced them to flee or attempt to blend in with locals, residents said. A colonel in the Malian army had said earlier that a "fringe of the Diabaly population adheres to the jihadists' theories and we must be very careful in the coming hours". French television footage from Diabaly has shown charred pick-up trucks abandoned by rebels amid mud brick homes. One resident said the rebels had fle...

Eritrea troops 'lay siege' to ministry

Dissident soldiers reportedly seize ministry and force state media to call for the release of political prisoners. A group of dissident Eritrean soldiers have laid siege to the information ministry and forced state media to announce a call for the release of political prisoners, according to a senior Eritrean intelligence official. The renegade soldiers forced the director of state television to make an announcement, the intelligence official said. "The soldiers have forced him to speak on state TV, to say the Eritrean government should release all political prisoners," the source said on condition of anonymity. Reports from Eritrea are difficult to independently verify, as the country restricts access to foreign media. Dozens of soldiers with two tanks surrounded the ministry building in Asmara, regional diplomatic sources said. They said state television and radio had gone off air. Araya Desta, Eritrea's permanent representative to the UN, said: "There is no prob...

Yemen: US drone strike kills 3 al-Qaida militants

By AHMED AL-HAJ Associated Press SANAA, Yemen (AP) -- A U.S. drone airstrike on a vehicle Monday east of Yemen's capital of Sanaa killed three suspected al-Qaida militants and wounded two others, according to security officials. The airstrike was the third to target al-Qaida militants in the area since Saturday and indicated an uptick in the U.S. military battle against the terror organization in Yemen. On Saturday, two U.S. drone strikes killed eight people, including two known al-Qaida militants, in Marib province. The security officials said the five targeted Monday were traveling in a pickup truck when it was hit in Marib, about 40 kilometers (25 miles) outside its main city with the same name. Two were killed on site, while another died hours later of his wounds, according to the officials, who spoke on condition of anonymity because they were not authorized to brief the media. Two of those killed were identified as Ali Saleh Toaiman and Qassim Nasser Toaiman. Both were member...

Moscow to start evacuating Russians from Syria

By BASSEM MROUE and VLADIMIR ISACHENKOV Associated Press BEIRUT (AP) -- Russia said Monday it is sending two planes to Lebanon to start evacuating its citizens from Syria, the strongest sign yet that President Bashar Assad's most important international ally has serious doubts about his ability to cling to power. The Russian announcement came as anti-government activists reported violence around the country, including air raids on the town of Beit Sahm near Damascus International Airport, just south of the capital. Russian officials said about 100 of the tens of thousands of Russian nationals in the country will be taken out overland to Lebanon and flown home from there, presumably because renewed fighting near the airport in Damascus has made it too dangerous for the foreigners to use that route out of the Syrian capital. Assad has dismissed calls that he step down. He has proposed a national reconciliation conference, elections and a new constitution, but the opposition insists h...

Everything we know so far about drone strikes

You might have heard about the "kill list." You've certainly heard about drones. But the details of the U.S. campaign against militants in Pakistan, Yemen, and Somalia — a centerpiece of the Obama administration's national security approach — remain shrouded in secrecy. Here's our guide to what we know — and what we don't know. Where is the drone war? Who carries it out? Drones have been the Obama administration's tool of choice for taking out militants outside of Iraq and Afghanistan. Drones aren't the exclusive weapon — traditional airstrikes and other attacks have also been reported . But by one estimate, 95 percent of targeted killings since 9/11 have been conducted by drones. Among the benefits of drones: they don't put American troops in harm's way. The first reported drone strike against al-Qaida happened in Yemen in 2002 . The CIA ramped up secret drone strikes in Pakistan under President George W. Bush in 2008 . Under President Bara...

MH-60S underpowered for MCM towing operations, report finds

The US Navy's (USN's) future airborne mine countermeasure (AMCM) MH-60S helicopter is unable to tow the minehunting sonar or minesweeping system forming part of the Littoral Combat Ship (LCS) mine countermeasures module (MCM) mission module, the Pentagon's Director of Operational Test and Evaluation (DOT&E) revealed in his annual report, released 15 January. "The navy determined the MH-60S helicopter cannot safely tow the AN/AQS-20A Sonar Mine Detecting Set (AQS-20A) or the Organic Airborne Sweep and Influence System (OASIS) because the helicopter is underpowered for these operations," read the Office of the Secretary of Defense's Fiscal Year 2012 report from DOT&E, Dr J Michael Gilmore. "The MH-60S helicopter will no longer be assigned these missions operating from any ship, including LCS," it added. Speaking to  IHS Jane's on 15 January, a USN official said the navy found that the MH-60S had insufficient power to operat...