Monday, November 21, 2011
A couple of reasons not to shop on Black Friday
Wednesday, November 16, 2011
SKYWATCH: Leonid meteor shower tonight
According to forecaster Jérémie Vaubaillon, Earth might pass through a filament of dust from Comet Tempel-Tuttle around 22h36m UT on November 16. The encounter could produce a brief flurry of Leonid meteors. If it's dark where you live, keep an eye on the sky.
Monday, November 14, 2011
SOLAR WATCH: Remarkable Solar activity underway
In terms of solar flares, the sun is quiet today. Nevertheless, some impressive activity is underway on the sun. For one thing, an enormous wall of plasma is towering over the sun's southeastern horizon. Stephen Ramsden of Atlanta, Georgia, took this picture on Nov. 11th: "Solar forums all over the world are buzzing with Sun-stronomers proclaiming this to be the biggest prominence that many of them had ever witnessed," he says. Remarkably, though, this is not the biggest thing. A dark filament of magnetism is winding halfway around the entire sun. NASA's Solar Dynamics Observatory took this picture during the early hours of Nov. 14th:
VENUS-DIRECTED CME: A coronal mass ejection (CME, movie) that swept past Mercury on Nov. 13th will likely hit Venus later today. Because Venus has no global magnetic field to protect it, the impact could erode material directly from the top of the planet's atmosphere. It's okay; Venus has atmosphere to spare. Analysts at the Goddard Space Weather Lab calculated the path of the CME, which left the sun on Nov. 12th. "Solar forums all over the world are buzzing with Sun-stronomers proclaiming this to be the biggest prominence that many of them had ever witnessed," he says.
Remarkably, though, this is not the biggest thing. A dark filament of magnetism is winding halfway around the entire sun. NASA's Solar Dynamics Observatory took this picture during the early hours of Nov. 14th:
From end to end, this twisted fiber of magnetism stretches more than a million km or about three times the distance between Earth and the Moon. If the filament becomes unstable, as solar filaments are prone to do, it could collapse and hit the stellar surface below, triggering a Hyder flare. No one can say if the eruption of such a sprawling structure would be Earth directed.
Wednesday, November 9, 2011
Dow Down 385: U.S. stocks dive as Italian yields rise
NEW YORK (MarketWatch) 2:54 p.m. — U.S. stock indexes dropped sharply Wednesday as Italy’s borrowing costs shot up to levels seen as unsustainable, further worsening Europe’s credit mess. “Those Italian bond yields run up and the market takes a dump, I think it’s a reflection of the concerns that are still out there. There is nothing new; I don’t think long-term investors are running for the door because Silvio Berlusconi is no longer going to be [Italy’s] prime minister,” said Bob Pavlik, chief market strategist at Banyan Partners. Worst year for bank revenue since ‘38 The fallout from Europe's debt crisis underscores the fragility of the U.S. financial system and its overseas exposure, according to analyst Mike Mayo, who also discusses the Occupy protest movement and what stocks he still likes. The Dow Jones Industrial Average DJIA -3.08% skidded 276.54 points to 11,893.64, with all of its 30 components on the run.
Monday, November 7, 2011
SKYWATCH: Asteroid flyby will come closer to us than the moon
ASTEROID FLYBY: NASA radars are monitoring 2005 YU55, an asteroid the size of an aircraft carrier, as it heads for a Nov. 8th flyby of the Earth-Moon system. There is no danger to our planet. At closest approach on Tuesday at 3:28 pm PST (23:28 UT), the 400m-wide space rock will be 324,600 kilometers away, about 85% the distance from Earth to the Moon. Professional astronomers are eagerly anticipating the flyby as the asteroid presents an exceptionally strong radar target. Powerful transmitters at Goldstone and Arecibo will ping the space rock as it passes by, revealing the asteroid's shape and texture in crisp detail, and pinpointing its orbit for future flyby calculations. A movie from JPL explains:
Thursday, November 3, 2011
SOLAR WATCH: Huge sunspot appearing on our sun
MAGNIFICENT SUNSPOT: One of the largest sunspots in years is rotating over the sun's northeastern limb. NASA's Solar Dynamics Observatory took this picture of AR1339 during the early hours of Nov. 3rd:
Measuring some 40,000 km wide and at least twice that in length, the sprawling sunspot group is an easy target for backyard solar telescopes. Two or three of the sunspot's dark cores are wider than Earth itself.
Naturally, such a large sunspot has potential for strong flares. NOAA forecasters estimate a 50% chance of M-class solar flares during the next 24 hours. One such eruption has already occured: An M4-flare at 2200 UT on Nov. 2nd produced a bright flash of extreme UV radiation (SDO movie) and hurled a coronal mass ejection (CME) into space. The CME is not heading our way. Future CMEs could have greater effect as AR1339 turns toward Earth in the days ahead. S
Wednesday, November 2, 2011
Asteroid flyby a missed lander opportunity?
USA TODAY - With a large asteroid zipping into Earth's neighborhood on Nov. 8, coming closer than the moon, we asked a NASA expert whether a probe landing on the object, 2005 YU55, was ever an option. After all, NASA's space marching orders now include asteroid exploration as an option, and the space agency's Dawn mission had to venture out beyond the orbit of Mars to reach the 330-mile-wide asteroid Vesta this July. Why not visit the smaller, but interesting 2005 YU55 on its visit, given another one its size won't come this close until 2028? "It would be difficult," says asteroid expert Don Yeomans of NASA's Jet Propulsion Laboratory in Pasadena, Calif. The best asteroids for landings are nearby ones that follow nearly circular orbits like Earth, he says, in terms of rocket fuel costs. Asteroid 2005 YU55 instead follows an oval orbit that takes it from Venus to Mars and zips through the Earth-Moon system at 30,600 miles per hour, relative to Earth. "We would have to race to catch up to it," Yeomans says.
Step Closer to Nuclear Showdown?
AP - Sources say Israeli Prime Minister Benjamin Netanyahu, is rallying support for pre-emptive attack on Tehran's atomic facilities — following a successful test of long-range Jericho rocket, capable of carrying a nuke — as Iran's leaders warn of 'heavy damage' should Israel strike.