6.3-magnitude quake hits Indonesia

CILACAP, Indonesia (AFP) – A 6.3-magnitude earthquake hit Central Java on Tuesday, around 120 kilometres southwest of Cilacap at a depth of 24 kilometres (14.9 miles), according to local officials.

The local meteorology, climatology and geophysics agency said there was no tsunami alert but the quake was followed by an aftershock of 5.0 magnitude.

The US Geological Survey measured the original quake at a much weaker 5.4-magnitude and a depth of 78 kilometres (48 miles).

A disaster management official in Cilacap said that so far there was no report of damage from the area although it had caused panic.

"When the quake hit, we felt a strong tremor. Many people ran outside their houses," the official Suherman, who uses only one name said.

"Now the disaster management officials are trying to calm people here," he added.

An AFP reporter said there was no report of damage so far at a refinery belonging to state oil and gas firm Pertamina in Cilacap.

Indonesia sits on the Pacific "Ring of Fire", where the meeting of continental plates causes high seismic activity, and is frequently hit by earthquakes.

Source: Yahoo! News

Satellite Photographs 'Black Hole' on Earth

A Korean satellite has caught an eye-catching view of an island in Mexico known for a deep, rocky hole and waters so dark that they earned it the name Holbox, a name that means "black hole."

The photo was taken by the Korea Multi-purpose Satellite 2, or Kompsat-2, and shows Holbox Island and its Yalahau lagoon at the northeast corner of Mexico's Yucatan Peninsula. [Photo of Earth's "black hole"]

Holbox Island is a 26-mile-long (42-kilometers) strip of land separated from the mainland by the lagoon.

"The freshwater lagoon has a deep rocky hole that surrounds the island, making the water appear black," officials with the European Space Agency, which is a partner in the Kompsat-2 mission, explained in a statement. "It is thought that Holbox, which in Mayan translates as 'black hole,' was named after the dark lagoon water."

Holbox Island is situated at an oceanic meeting point of sorts where the Atlantic Ocean, Gulf of Mexico and Caribbean converge. The mixing of these waters creates a nutrient-rich environment that supports an abundant array of marine life, ESA officials said. [The World's Biggest Oceans and Seas]

At Caboe Catoche, a cape at the eastern tip of the island, the mixing of the Caribbean and Gulf of Mexico creates a veritable kaleidoscope of watery turquoise and emerald colors.

Because of its host of marine life, Holbox Island and its surrounding waters are protected as part of the Yum Balam Biosphere Reserve. The island's beaches of white coralline sand serve as a vital home for turtle nests and more than 500 species of birds, while dolphins, manta rays and several shark species swim offshore.

The region is also home to the world’s largest known gathering of whale sharks — the largest fish on the planet — for five months of the year, ESA officials said.

The Kompsat-2 satellite has been snapping photos of Earth from orbit since it launched into space in 2006. The satellite was built for the Korea Aerospace Research Institute to provide uninterrupted Earth observation coverage following its predecessor, Kompsat-2.

ESA serves as a third-party partner in the mission and uses ground-based infrastructure to receive, process and distribute the images from Kompsat-2.

This article was provided by OurAmazingPlanet, a sister site to SPACE.com.

Source: Yahoo! News

At least 35 dead in 6 states after storm's rampage

RALEIGH, N.C. – A furious storm system that kicked up tornadoes, flash floods and hail as big as softballs has claimed at least 35 lives on a rampage that began in Oklahoma days ago, then smashed across several Southern states as it reached a new and deadly pitch in North Carolina and Virginia.

Emergency crews searched for victims in hard-hit swaths of North Carolina, where 62 tornadoes were reported from the worst spring storm in two decades to hit the state. Ten people were confirmed dead in Bertie County, county manager Zee Lamb said. At least three deaths were reported in Virginia. Authorities warned the toll was likely to rise further Sunday as searchers probed shattered homes and businesses.

The storm claimed its first lives Thursday night in Oklahoma, then roared through Arkansas, Mississippi, Alabama and Georgia. Seven people each were killed in Arkansas and Alabama, two people in Oklahoma and one person in Mississippi, authorities have said.

In North Carolina, Gov. Beverly Perdue declared a state of emergency after reporting fatalities in at least four counties. But she declined to immediately confirm an exact number of deaths. She said the 62 tornadoes reported were the most since March 1984, when a storm system spawned 22 twisters in the Carolinas that killed 57 people — 42 in North Carolina — and injured hundreds.

"Our thoughts and prayers are with everybody in North Carolina who has been through this horrible day," Perdue said.

Daybreak brought news of a horrific death toll in Bertie County, a place of about 21,000 people about 130 miles east of Raleigh. The tornado moved through about 7 p.m. Saturday, sweeping homes from their foundations, demolishing others and flipping cars on tiny rural roads between Askewville and Colerian, Lamb said.

One of the volunteers who scoured the rubble was an Iraq war veteran who told Lamb he was stunned by what he saw.

"He did two tours of duty in Iraq and the scene was worse than he ever saw in Iraq — that's pretty devastating," Lamb said.

As dawn broke, dozens of firefighters, volunteers and other officials were meeting in a makeshift command center to form search teams to fan out to the hardest-hit areas.

"There were several cases of houses being totally demolished except for one room, and that's where the people were," he said. "They survived. Pretty devastating."

Authorities in North Carolina said they would provide more details of the death toll later Sunday after checking on the reports of fatalities in at least four counties and in the capital city of Raleigh. Search and rescue teams operated through the night, Perdue said, with damage assessments starting in earnest Sunday after daylight.

"There's a lot of work that needs to be done in these areas that are most heavily impacted," said Doug Hoell, the state's director of emergency management. "There's a lot of debris out there that's got to be cleaned up."

In Virginia, disaster officials said one apparent tornado ripped across more than 12 miles through Gloucester County, uprooting trees and pounding homes to rubble while claiming three lives. Another person was confirmed dead and another remained missing early Sunday after flash flooding elsewhere in Virginia.

Scenes of destruction across the South looked eerily similar in many areas.

In North Carolina, rooftops were ripped off stores, trees were plucked from the ground and scores of homes were damaged, Hoell said.

At one point, more than 250,000 people went without power in North Carolina before emergency utility crews began repairing downed lines. But scattered outages were expected to linger at least until Monday.

Among areas hit by power outages was Raleigh, a bustling city of more than 400,000 people where some of the bigger downtown thoroughfares were blocked by fallen trees early Sunday.

Police and rescue crews began conducting house-to-house searches later Saturday at a mobile home park in north Raleigh, where the storm snapped some trees in half, ripped others out of the ground and tossed some trailers from one side of a street to the other.

In Sanford, about 40 miles southwest of Raleigh, a busy shopping district was pummeled by the storms, with some businesses losing rooftops in what observers described as a ferocious tornado. The Lowe's Home Improvement Center in Sanford looked flattened, with jagged beams and wobbly siding sticking up from the pancaked entrance. Cars in the parking lot were flipped by the winds.

"It's very, very bad here," said Monica Elliott, who works at the nearby Brick City Grill. "We saw a tornado that just rode up over the restaurant."

Remarkably, no one was seriously injured at the Lowe's, thanks to a quick-thinking manager who herded more than 100 people into a back area with no windows to shatter.

"It was really just a bad scene," said Jeff Blocker, Lowe's regional vice president for eastern North Carolina. "You're just amazed that no one was injured."

Cindy Hall, a Red Cross volunteer and outreach minister at First Baptist Church in Sanford, said dozens of homes in the area were damaged.

"It wiped out our St. Andrews neighborhood, which includes about 30 homes," she said.

To the west, hikers stranded by flash floods had to be rescued.

In Virginia, Department of Emergency Management spokesman Bob Spieldenner, said an apparent tornado ploughed through communities of Gloucester County, destroying or damaging homes, uprooting trees in a quiet farming and fishing region along the Chesapeake Bay.

"I know it was a pretty long path," he said of the reported tornado. "They estimated it was 12 to 14 miles" based on 911 emergency calls.

Authorities said at least three deaths had been confirmed in Gloucester County and at least 60 were injured, most with minor injuries. Spieldenner said one person was killed when a vehicle ran into flash flooding near Waynesboro. Another person was missing and a third rescued.

He reported homes and mobile homes damaged and destroyed in a series of other Virginia counties and flash flooding west of Charlottesville that prompted water rescues — including four people rescued unhurt from a car that had plunged into deep water flowing over a street.

___

Associated Press writers Page Ivey in Columbia, S.C., Jackie Quinn in Washington, D.C., and Jeff Martin and Jacob Jordan in Atlanta contributed to this report.

Source: Yahoo! News

April's Full Moon Arrives Sunday With Easter Name

Astronaut Paolo Nespoli took this image of the moon aboard the International Space Station on March 20, 2011, and wrote, "#Supermoon was spectacular from here!"

Sunday (April 17) brings us the first full moon of the new spring season in the Northern Hemisphere, bringing a lunar delight named – in part – for Easter.

The official moment that the moon will turn full is 10:44 p.m. EDT (7:44 p.m. PDT). Traditional names for the full moons of the year are found in some publications such as The Farmers' Almanac and we published the complete list on SPACE.com earlier this year.

The origins of these names have been traced back to native America, though they may also have evolved from old England or, as Guy Ottewell, editor of the annual publication, "Astronomical Calendar" suggests, "writer's fancy."

Traditionally, the April full moon is known as the "Pink Moon,"supposedly because the grass pink or wild ground phlox is one of the earliest widespread flowers of the spring. Other monikers were the Full Sprouting Grass Moon, the Egg Moon, and – among coastal tribes – the Full Fish Moon, when the shad come upstream to spawn. ['Supermoon' Photos from Around the World]

Easter's full moon twist
The first full moon of spring, however, is usually designated as the Paschal Full Moon or the Paschal Term. Traditionally, Easter is observed on the Sunday after the Paschal Full Moon. So if the Paschal Moon occurs on a Sunday, Easter is the following Sunday.

Following these celestial rules, we find that Easter can fall as early as March 22 and as late as April 25.

Pope Gregory XIII decreed this in 1582 as part of the Gregorian calendar. So according to the current ecclesiastical rules Easter in 2011 is to be celebrated nearly as late as it can come, on April 24.

Interestingly however, these rules also state that the vernal equinox is fixed on March 21, even though at European longitudes from the years 2008 through 2101 the equinox will occur no later than March 20.

Hence, there can sometimes be discrepancies between the ecclesiastical and astronomical versions for dating Easter.

In the year 2038, for instance, the equinox falls on March 20 with a full moon the next day, so astronomically speaking, Easter should fall on March 28 of that year. In reality, however, as mandated by the rules of the Church, Easter in 2038 will be observed as late as it can possibly come, on April 25!

Adding additional confusion is that there is also an "ecclesiastical" full moon, determined from ecclesiastical tables and whose date does not necessarily coincide with the "astronomical" full Moon, which is based solely on astronomical calculations. [Infographic: Earth’s Moon Phases Explained]

In 1981, for example, the full moon occurred on Sunday, April 19, so Easter should have occurred on the following Sunday, April 26. But based on the ecclesiastical full Moon it occurred on the same day of the Full Moon, April 19!

So, in practice, the date of Easter is determined not from astronomical computations, but rather from other formulae such as Epachs and Golden Numbers.

Since the beginning of the 20th century, a proposal to change Easter to a fixed holiday rather than a movable one has been widely circulated, and in 1963 the Second Vatican Council agreed, provided a consensus could be reached among Christian churches. The second Sunday in April has been suggested as the most likely date.

Spring Counterpart to the Harvest Moon

Traditionally the full moon ccurring nearest to the autumnal equinox is traditionally called the Harvest Moon. What sets the Harvest Moon apart from the others is that instead of rising at its normal average of 50 minutes later each day, it seems to rise at nearly the same time for several nights.

But in direct contrast to the Harvest Full Moon, the Paschal Full Moon appears to rise considerably later each night. Below we’ve provided some examples for ten North American cities.

The local moonrise times for April 16, 17, 18 are provided, the middle date being that of the Paschal Full moon.

This table shows moonrise times for April 16-18, 2011, at North American locations.
CREDIT: Joe Rao

Although normally the moon rises about 50 minutes later each night, over this three-night interval for our relatively small sampling, we can see that the rising of the moon comes, on the average, 77 minutes later each night.

A quick study of the table shows that the night-to-night difference is greatest for the more northerly locations (Edmonton, located at latitude 53.6 degrees north, sees moonrise come a full 90 minutes later on average). Meanwhile, the difference is less at southerly locations (at Miami, Florida located at latitude 26ºN, the average difference is about 68 minutes).

The reason for this seasonal circumstance is that the moon appears to move along the ecliptic and at this time of year when rising, the ecliptic makes its largest angle with respect to the horizon for those living in the Northern Hemisphere.

In contrast, for those living in the Southern Hemisphere, the ecliptic at this time of year appears to stand at a more oblique angle to the eastern horizon. As such, the difference for the time of moonrise is noticeably less than the average of 50 minutes per night. In Sydney, Australia, for instance, the night-to-night difference amounts to just 40 minutes.

Some final thoughts
For all who are making preparations for the upcoming Easter holiday, here's something to consider: Last month, had the moon officially turned full just 29 hours 50 minutes later than it actually did, it would have been designated as the Paschal Moon and Easter would have already occurred on March 27.

And while much ado was made about the near coincidence of last month's full moon with perigee (the closest point in its orbit relative to earth) the full moon of April 17 also occurs close to perigee.

In this case, perigee occurs about 21 hours before the moon turns full. Its distance from Earth: 222,506 miles (358,090 kilometers) is less than a half percent more distant than last month’s so-called "Super" moon. So, as was the case last month, the April full moon will appear to loom abnormally large when it rises or sets and will cause the daily range of ocean tides to be more extreme for a few days after full moon.

It’s just not considered a "super" moon. Go figure …

So while this April full moon wins the title of Paschal Moon by a margin of less than 30 hours, it falls short of being called a "Super" moon by just 941 miles (1,515 km); a distance that measures less than half of the diameter of the moon itself!

Source: Space.com

NASA Photos Bring Millions of Galaxies and Asteroids Down to Earth

When viewed in infrared light, NASA's Wide-field Infrared Survey Explorer, or WISE, shows a giant nebula around Lambda Orionis, inflating Orion's head to huge proportions.
CREDIT: NASA/JPL-Caltech/UCLA

NASA has unveiled a flood of photos showing millions galaxies, stars and asteroids photographed by a prolific sky-mapping telescope that ended its mission earlier this year.

For the first time, the space agency publicly released more than half of the 2.7 million images taken by its Wide-field Infrared Survey Explorer (WISE) telescope during its mission to map the entire sky.

WISE launched in December 2009 and spent 14 months scanning the heavens in infrared light before shutting down this past February. The $320 million space telescope hunted for asteroids and comets, as well as more distant cosmic objects revealed by their faint glow. [Photos from NASA's WISE Telescope]

WISE's infrared eyes were especially useful for peering through dense layers of dust to capture stunning space photos of previously unseen objects in unprecedented detail.

The telescope's observations have been used by mission scientists since they first started rolling in, but this is the first time a large amount of the data collected by WISE is being opened to the public, including scientists not affiliated with the project. Researchers are expecting the broadened exposure of the photos will enable a new wave of scientific discoveries.

"Starting today thousands of new eyes will be looking at WISE data, and I expect many surprises," the mission's principal investigator Edward (Ned) Wright, of UCLA, said in a statement.

While circling the Earth in a polar orbit, WISE captured images of faraway galaxies and nearby asteroids. During its tenure, the telescope surveyed the entire sky about 1 1/2 times in four different wavelengths of light.

WISE discovered 20 new comets, more than 33,000 asteroids between Mars and Jupiter, and 133 near-Earth objects (NEOs), which are asteroids that come within 28 million miles (about 45 million kilometers) of Earth.

The data released today includes about 57 percent of the photos taken by WISE over the course of its mission, NASA officials said. The remaining images will be released to an online archive in the spring of 2012.

"We are excited that the preliminary data contain millions of newfound objects," said Fengchuan Liu, the project manager for WISE at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But the mission is not yet over — the real treasure is the final catalog available a year from now, which will have twice as many sources, covering the entire sky and reaching even deeper into the universe than today's release."

So far, the WISE mission has released dozens of colorful images of the cosmos, in which infrared light has been assigned colors we see with our eyes. The whole collection can be seen at http://wise.ssl.berkeley.edu/gallery_images.html.

The public archive for astronomers is online at http://wise2.ipac.caltech.edu/docs/release/prelim/index.html. Instructions for astronomy enthusiasts wanting to try their hand at using the archive are at http://wise.ssl.berkeley.edu/wise_image_service.html.

Source: Space.com

Rare Sight: Mercury to Meet Mars at Dawn on Tuesday

The planets Mercury and Mars will be in close conjunction on the morning of April 19.
CREDIT: Starry Night Software

Skywatchers set your alarm clocks: On Tuesday morning (April 19), Mercury will appear to have a close encounter with Mars.

In reality, the two planets will actually be separated by about 161 million miles (259 million kilometers), but in Earth’s sky they will appear only 2 degrees (which is about four moon widths) apart. You'll need to be up just before the sun, around 6:30 a.m. local time, to see this rare sight.

Mercury and Mars will appear very low in the eastern sky and will be difficult to see in morning twilight. You will need a very low eastern horizon, with few obstacles in the way.

Small binoculars will be a big help in spotting the two tiny specks of light, but first make sure the sun is safely behind a hilltop or other obstruction, as in this sky map of Mars and Mercury.

You can also use the much brighter planets Venus and Jupiter to locate Mercury and Mars.

To ancient astrologers, such conjunctions were fraught with ominous significance. To modern astronomers, they are merely a pretty sight, a photo opportunity. [Latest Mercury photos from NASA probe]

This is the first of a whole series of close encounters between six planets in the morning sky over the next two months. Saturn won’t participate in the dawn dance, since it is currently dominating the evening sky.

Here is a run-down of these upcoming conjunctions:
April 19: Mercury and Mars
April 22: Venus and Uranus
May 1: Mars and Jupiter
May 8: Mercury and Venus
May 10: Mercury and Jupiter
May 11: Venus and Jupiter
May 18: Mercury and Venus (again)
May 20: Mercury and Mars (again)
May 22: Venus and Mars

Because of its rapid motion relative to the sun, Mercury manages two conjunctions each with both Venus and Mars. In addition, the waning crescent moon will pass through the gathering of planets in late April and again in late May.

Neptune is the only dawn planet not to be involved in a conjunction, because it is too far to the west.

These planet conjunctions offer many opportunities for beautiful photographs with ordinary cameras.

Use your lens at its longest telephoto setting, underexpose slightly to bring out the colors of the dawn sky, and try to frame the planets with the silhouettes of foreground objects.

Article by: Starry Night Education, the leader in space science curriculum solutions.

Source: Space.com

Yellowstone Supervolcano Bigger Than Thought

The gigantic underground plume of partly molten rock that feeds the Yellowstone supervolcano might be bigger than previously thought, a new image suggests.

The study says nothing about the chances of a cataclysmic eruption at Yellowstone, but it provides scientists with a valuable new perspective on the vast and deep reservoir of fiery material that feeds such eruptions, the last of which occurred more than 600,000 years ago. [Related: Infographic - The Geology of Yellowstone.]

Earlier measurements of the plume were produced by using seismic waves — the waves generated by earthquakes — to create a picture of the underground region. The new picture was produced by examining the Yellowstone plume's electrical conductivity, which is generated by molten silicate rocks and hot briny water that is naturally present and mixed in with partly molten rock.

"It’s a totally new and different way of imaging and looking at the volcanic roots of Yellowstone," said study co-author Robert B. Smith, professor emeritus and research professor of geophysics at the University of Utah, and a coordinating scientist of the Yellowstone Volcano Observatory.

Ancient eruptions
Almost 17 million years ago, the deep plume of partly molten rock known as the Yellowstone hot spot first breached the surface in an eruption near what is now the Oregon-Idaho-Nevada border.

As North America drifted slowly southwest over the hot spot, there were more than 140 gargantuan caldera eruptions — the largest kind of eruption on Earth — along a northeast-trending path that is now Idaho's Snake River Plain.

The hot spot finally reached Yellowstone about 2 million years ago, yielding three huge caldera eruptions about 2 million, 1.3 million and 642,000 years ago.

Two of the eruptions blanketed half of North America with volcanic ash, producing 2,500 times and 1,000 times more ash than the 1980 eruption of Mount St. Helens in Washington state. Smaller eruptions occurred at Yellowstone in between the big blasts and as recently as 70,000 years ago.

Underground images
Smith said the geoelectric and seismic images of the Yellowstone plume look somewhat different because "we are imaging slightly different things." Seismic images highlight materials such as molten or partly molten rock that slow seismic waves, while the geoelectric image is sensitive to briny fluids that conduct electricity.

Seismic images of the plume made by Smith in 2009 showed the plume of molten rock dips downward from Yellowstone at a 60-degree angle and extends 150 miles (240 kilometers) west-northwest to a point at least 410 miles (660 km) under the Montana-Idaho border — as far as seismic imaging could "see."

The new electrical conductivity images show the conductive part of the plume dipping more gently, at an angle of perhaps 40 degrees to the west, and extending perhaps 400 miles (640 km) from east to west. The geoelectric image can "see" to a depth of only 200 miles (320 km).

The lesser tilt of the geoelectric plume image raises the possibility that the seismically imaged plume, shaped somewhat like a tilted tornado, may be enveloped by a broader, underground sheath of partly molten rock and liquids, Zhdanov and Smith say.

"It's a bigger size" in the geoelectric picture, Smith said. "We can infer there are more fluids" than shown by seismic images. Despite differences, he said, "this body that conducts electricity is in about the same location with similar geometry as the seismically imaged Yellowstone plume."

The new study has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union, which plans to publish it within the next few weeks.

Image Gallery: Yellowstone and Yosemite
Infographic: Tallest Mountain to Deepest Ocean Trench
Which U.S. Volcanoes Are Most Dangerous Right Now?

This article was provided by OurAmazingPlanet, a sister site to LiveScience.
Source: Yahoo! News

The Moon Visits Two Star Clusters in Night Sky

Over the next few days, the moon will move past two of the prettiest star clusters in the sky.

Tonight (April 6) the moon will be located just below the brightest star cluster we can see from Earth — the Pleiades, which is found in the constellation Taurus. By Saturday, the moon will nearing another nice cluster, known as Messier 35.

The Pleiades cluster has been known since antiquity by nearly every culture around the world. It is best known as the Pleiades or the Seven Sisters, even though only six of its stars are readily visible with the naked eye.

This sky map of the moon and star clusters shows how they will appear together this week.

Not the Little Dipper
Beginning stargazersoften mistake the Pleiades for the Little Dipper, because it is dipper-shaped and much brighter than the real Little Dipper. In Japanese, the cluster is known as Subaru, and the Japanese automakeruses a picture of the Pleiades as its logo. In Australia, the Pleiades are known as “the Shopping Cart.”

Tonight, the Pleiades are easily seen just above the thin waxing crescent moon. By Thursday, the moon will have moved so that it is above and to the left of the Pleiades. The cluster will be readily visible with the naked eye on both nights, though it looks even better in binoculars or a small telescope. With either of those vision aids, hundreds of stars in this cluster become visible.

By Saturday night (April 9) the moon will have moved on from Taurus into Gemini, and it will be near another fine cluster. This one has no name, only a number in the famous catalog compiled by Charles Messier: Messier 35 (or M35 for short).

Charles Messier was an eminent hunter of comets in the 18th century. To make identification of comets easier, he compiled a list of permanent objects in the sky that look somewhat like comets. His list contains 110 objects that represent the brightest and best deep-sky objects in the heavens: star clusters, nebulae and galaxies.

Observing his list has become a popular project for amateur astronomers, who attempt to spot all 110 objects Messier saw. In the process, they learn what deep-sky objects look like, and how to find their way around the sky.

Messier 35
Messier first observed the M35 cluster on August 30, 1764. This cluster has many more stars than the Pleiades, but is seven times farther away from us — 2,850 light-years as opposed to 410 light-years for the Pleiades. In binoculars it just appears as a dim glow; it takes a small telescope to resolve it into stars.

The Pleiades are also in Messier’s catalog as Messier 45, but he did not discover that cluster. When he was about to publish his catalog for the first time, Mesier added a few well-known objects to pad its numbers up to 45, including the Orion Nebula (Messier 42 and 43), the Beehive Cluster (Messier 44) and the Pleiades (Messier 45).

Some years later, Messier published a larger catalog of 103 objects, and noted in his personal copy six more, bringing the total to 109. In recent years, astronomers have added a last object to bring the total to an even 110 objects. This last object is one of the two satellite galaxies of the Andromeda Galaxy (Messier 31), which Messier observed and drew, but never assigned a number.

This article was provided to SPACE.com by Starry Night Education, the leader in space science curriculum solutions.

Source: Space.com

Strongest aftershock since Japan tsunami kills 2

By JAY ALABASTER and TOMOKO A. HOSAKA
Associated Press

SENDAI, Japan (AP) -- A strong aftershock ripped through northeastern Japan, killing two people, knocking out power to vast areas Friday and piling misery on a region still buried under the rubble of last month's devastating tsunami.

The northeastern coast was still reeling from the destruction wrought by a jumbo 9.0-magnitude earthquake on March 11, with tens of thousands of households without power or water. The 7.1 tremor has now thrown even more areas into disarray and sent communities that had made some gains back to square one.

Gasoline that had become more available after weeks of shortages was scarce again, and long lines formed at stations. Stores that had restocked shelves sold out of basics Friday and were forced to ration purchases again.

Still, the latest quake did far less damage, generated no tsunami and largely spared the region's nuclear plants. Some slightly radioactive water spilled at one plant, but the tsunami-crippled Fukushima Dai-ichi complex reported no new problems.

Matsuko Ito, who has been living in a shelter in the small northeastern city of Natori since the tsunami, said there's no getting used to the terror of being awoken by shaking. She said she started screaming when the quake struck around 11:30 p.m.

"It's enough," the 64-year-old while smoking a cigarette outside. "Something has changed. The world feels strange now. Even the way the clouds move isn't right."

The latest tremor sunk more homes into blackness, though power was quickly restored to many. About 950,000 households were still dark Friday evening, said Souta Nozu, a spokesman for Tohoku Electric Power Co., which serves northern Japan. That includes homes in prefectures in Japan's northwest that had been spared in the first quake.

Six conventional plants in the area were knocked out, though three have since come back online and the others should be up again within hours, Nozu said. But with power lines throughout the area damaged, it was not clear whether normal operations would be restored, he said.

In Ichinoseki, lines formed outside a supermarket when it opened Friday morning. An employee with a flashlight escorted each customer around the store and jotted the price of each selected item in a pad.

Most businesses were closed in the city, 240 miles (390 kilometers) northeast of Tokyo. One restaurant owner, Suzuki Koya, bought a small gas stove and made free meals in big boiling pot.

"I saw the meat at the supermarket and I thought, 'We should do a hot pot,' " the 47-year-old said. "It's good to keep warm in times like these."

Several nuclear power plants briefly switched to diesel generators but were reconnected to the grid by Friday afternoon. One plant north of Sendai briefly lost the ability to cool its spent fuel pools, but quickly got it back.

At a plant in Onagawa, some radioactive water splashed out of the pools but did not leave a containment building, Tohoku Electric said. Such splash-out is "not unusual, although it is preferable that it doesn't happen," according to Japanese nuclear safety agency official Tomoho Yamada.

"Closer inspection could find more problems," said agency spokesman Hidehiko Nishiyama, but no radiation was released into the environment at Onagawa.

The plant began leaking oil into the ocean in the first earthquake, and the flow escaped a containment boom in Thursday's tremor but was contained again by Friday, coast guard spokesman Hideaki Takase said.

Thursday's quake prompted a tsunami warning of its own, but it was later canceled. Two people were killed, national fire and disaster agency spokesman Junichi Sawada reported Friday. A 79-year-old man died of shock and a woman in her 60s was killed when power was cut to her oxygen tank. More than 130 people were injured, according to the national police agency.

That pales in comparison to the original quake and tsunami, in which more than 25,000 people are believed to have died.

Many of those bodies have still not been found: A significant portion were likely washed out to sea and never will be, but some are buried in areas that have been largely off-limits to search teams.

As radiation spilling from the troubled Fukushima Dai-ichi plant has fallen in recent days, however, police have fanned out inside a no-go zone near the complex to dig for the dead.

On Friday, hundreds of police, many mobilized from Tokyo, used their hands or small shovels, pulling four bodies in an hour from one small area in the city of Minami Soma. The had found only five bodies the previous day.

The searchers, wearing white radiation gear and blue gloves, struggled to bring the remains across the rubble to vans and minibuses that would take them to the nearest morgue. Each body was carefully hosed off to rid it of radiation before being placed in the vehicles.

"The area is literally a mountain of debris. It is an extremely difficult task," said an official with police in Fukushima prefecture who declined to be named because he was not authorized to talk to the media.

The epicenter of Thursday's temblor was in about the same location as the original 9.0-magnitude tremor, off the eastern coast and about 40 miles (65 kilometers) from Sendai, an industrial city on the eastern coast, according to the U.S. Geological Survey. It was strong enough to shake buildings for about a minute as far away as Tokyo, about 200 miles (330 kilometers) away.

At a Toyota dealership in Sendai, most of a two-story show window was shattered, and thick shards of glass were heaped in front of the building. Police directed cars through intersections throughout the city on Friday because traffic lights were out. Small electrical fires were reported.

At the Fukushima Dai-ichi plant, where nuclear workers have been toiling to plug radiation leaks and restore cooling systems ruined in the March 11 quake and tsunami, workers briefly retreated to a shelter and suffered no injuries. The plant operator said the tremor caused no new problems there.

Despite the new aftershock, automakers announced Friday that they were beginning to bounce back from the March monster. Toyota will resume car production at all its plants in Japan at half capacity from April 18 to 27.

The world's No. 1 automaker said it remained unclear when it would return to full production in Japan.

Nissan also said it would start up domestic production at half capacity from April 11.

Operations had been halted at both companies because of part shortages.

Associated Press writers Shino Yuasa, Malcolm Foster, Ryan Nakashima, Mari Yamaguchi and Cara Rubinsky in Tokyo, Eric Talmadge in Minami Soma, and Colleen Slevin in Denver contributed to this report.

Article by: Associated Press

Mexico Earthquake 2011: Magnitude 6.5 Temblor Felt In Mexico City

MEXICO CITY -- A magnitude-6.5 earthquake shook a wide area of southern and central Mexico on Thursday(7 April 2011), sending people fleeing into the streets, but causing only minor reported damage.

The epicenter was located near Las Choapas, a town of about 83,000 residents about 370 miles (600 kilometers) southeast of Mexico City. It swayed buildings for several seconds in the capital, and in the Gulf coast state of Veracruz, people ran from their homes and school children assembled on playgrounds.

Near the epicenter, cracks in walls forced the evacuation of one elementary school, said Bernabe Hernandez Perez, head of civil protection in Las Choapas.

Gov. Javier Duarte de Ochoa said earlier that he had no reports of damage in the oil-producing state.

"Veracruz is completely quiet without problems," he told state television. "It was felt all over the state, but nothing major happened. It was only a scare."

The temblor also was felt strongly in the state of Chiapas, bordering Guatemala, where there also were no immediate reports of damage or injuries, as well as the Pacific coast state of Guerrero.

The U.S. Geological survey said the quake hit at a depth of 104 miles (167 kilometers).

Source:Huffingtonpost.com

Japan earthquake: Tsunami warning lifted, but Fukushima evacuated

Tokyo – A magnitude 7.1 earthquake struck off the coast of Japan's Miyagi Prefecture – the region worst affected by the huge March 11 quake and tsunami – at 11:32 p.m. local time on Thursday(7 April 2011). Evacuation orders were issued for hundreds of homes along the northeast coastline.

Tsunami advisories were immediately issued, but were lifted approximately one hour later. The quake is the strongest of the hundreds of aftershocks that have shaken Japan since the magnitude 9.0 temblor on March 11. That earthquake caused a tsunami that destroyed thousands of homes, displaced nearly a half million people, and severely crimped the iconic fishing industry there.

The center of the earthquake was 40 kilometers below the seabed, about 60 miles east of the city of Sendai and about 90 miles from Fukushima, according to Japan's Meteorological Agency.

Tokyo Electric Power Company (Tepco) says that the quake hasn’t caused any further damage to the Daiichi nuclear power plant and that all the workers have been temporarily evacuated from the facilities. There were no injuries reported.

Japan Fukushima nuclear crisis: A timeline of key events

Two out of three external power lines to the Onagawa nuclear power plant, 75 miles northeast of Fukushima and near the epicenter of Thursday's temblor, have been damaged, causing power loss. The plant, operated by Tohoku Electric Power, has been shut down since the March 11 quake and has been relying on external power to cool the reactors. Japan’s Atomic Energy Agency said the two lost power lines were not being used for cooling when tonight’s earthquake hit.

The Oshika Peninsula, on which the Onagawa plant is located, was also the closest part of the main Honshu island of Japan to the March 11 earthquake, which shifted the whole peninsula 27 feet to the southeast and sunk it 7 feet. The March 11 tsunami reached heights of 42.5 feet, just below the base of the nuclear plant.

The Meteorological Agency has said that no increased radiation levels have been detected around the plant.

Electricity blackouts have occurred across the northeast region and some highways have been closed.

The Tohoku, Joetsu, and Nagoya bullet train lines were stopped but were able to restart shortly afterwards. The lines closest to the earthquake had not resumed operations since March 11.

Source: Yahoo! News

Huge Asteroid to Pass Near Earth in November

The near-Earth asteroid named 2005 YU55 — on the list of potentially dangerous asteroids — was observed with the Arecibo Telescope's planetary radar on April 19, 2010 when it was about 1.5 million miles from the Earth, which is about 6 times the distance to the moon. Full Story.

Mark your calendars for an impressive and upcoming flyby of an asteroid that’s one of the larger potentially perilous space rocks in the heavens – in terms of smacking the Earth in the future.

It’s the case of asteroid 2005 YU55, a round mini-world that is about 1,300 feet (400 meters) in diameter. In early November, this asteroid will approach Earth within a scant 0.85 lunar distances.

Due the object’s size and whisking by so close to Earth, an extensive campaign of radar, visual and infrared observations are being planned.

Due the object’s size and whisking by so close to Earth, an extensive campaign of radar, visual and infrared observations are being planned.

Asteroid 2005 YU55 was discovered by Spacewatch at the University of Arizona, Tucson’s Lunar and Planetary Laboratory on Dec. 28, 2005. [Photos: Asteroids in Deep Space]

En route and headed our way, the cosmic wanderer is another reminder about life here on our sitting duck of a planet

Close and big

“The close Earth approach of 2005 YU55 on Nov. 8, is unusual since it is close and big. On average, one wouldn’t expect an object this big to pass this close but every 30 years,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office and the Jet Propulsion Laboratory in Pasadena, Calif.

Yeomans said that with new radar capabilities at Goldstone in California — part of NASA’s Deep Space Network — there is a good chance of obtaining radar imaging of 2005 YU55 down to the 5-meter resolution level. Doing so, he said, would mean obtaining higher spatial resolution of the object than that attained by recent spacecraft flyby missions.

“So we like to think of this opportunity as a close flyby mission with Earth as the spacecraft,” Yeomans told SPACE.com. “When combined with ground-based optical and near-infrared observations, the radar data should provide a fairly complete picture of one of the larger potentially hazardous asteroids,” he said. [5 Reasons to Care About Asteroids]

Asteroid 2005 YU55 is a slow rotator. Because of its size and proximity to Earth, the Minor Planet Center in Cambridge, Mass., has designated the space rock as a “potentially hazardous asteroid.”

Dishing it out

“We’re already preparing for the 2005 YU55 flyby,” said Lance Benner, a research scientist at JPL and a specialist on radar imaging of near-Earth objects. He said part of the plan is to observe the asteroid with radar using both the huge Arecibo dish in Puerto Rico and equipment at Goldstone.

“The asteroid will approach from the south, so Goldstone has the first chance to observe it due to its declination coverage,” Benner told SPACE.com.

To help coordinate the observing campaigns, “Radar Observations Planning” websites have been set up for this unusual occasion, Benner said.

“This flyby will be the closest by any near-Earth asteroid with an absolute magnitude this bright since 1976 and until 2028,” Benner added. “Having said that, nobody saw 2010 XC15 during its close flyby within 0.5 lunar distance in 1976,” he said, noting that this asteroid wasn’t discovered until late in 2010.

“Thus, the flyby by 2005 YU55 will be the closest actually observed by something this large, so it represents a unique opportunity,” Benner said. “In a real sense, this will provide imaging resolution comparable to or even better than a spacecraft mission flyby.”

Radar Paint

Benner said that because the asteroid is zooming by Earth so very close, radar echoes will be extremely strong. One facility at Goldstone will be used to transmit and “radar paint” the object…another Goldstone dish is on tap to snag the reflected echo of radar data.

What can radar do?

Information collected by this technique, for example, can be transformed into 3-D shapes, with surface features and spin rates identified. The asteroid’s roughness and density can also be assessed. Furthermore, radar can improve the whereabouts of the object. By greatly shrinking uncertainties for newly discovered meandering NEOs, that in turn enables motion prediction for decades to centuries.

As for seeing the asteroid with small telescopes, start getting your gear ready.

Initially, the object will be too close to the sun and too faint for optical observers.

But late in the day (Universal Time) on Nov. 8, the solar elongation will grow sufficiently to see it. Early on Nov. 9, the asteroid could reach about 11th magnitude for several hours before it fades as its distance rapidly increases, Benner explained.

Source: Space.com

Ghost city symbolises cost of nuclear disaster

PRIPYAT (AFP) – "Careful -- do not touch anything with your bare hands!" warned the guide as we entered the kindergarten and our Geiger counter hissed like an angry rattlesnake.

On the floor and shelves were plastic cubes and teddy bears and kiddies' books, just the things you would expect to find in a children's playgroup.

But these toys were coated in a thick leprous white dust, for they had lain undisturbed for almost a quarter of a century.

And scattered among them were infant-sized gas masks.

Something terrifying had made the toddlers flee their innocent corner of the world. Their home, Pripyat, once a model city, had become the set for a true-life apocalypse movie.

Cursed by the winds that blow from Chernobyl a few kilometres (couple of miles) away, Pripyat is a snapshot of the astronomical cost of the world's worst nuclear disaster. And its fate stirs chilling thoughts for Japan, grappling with its own nuclear crisis in Fukushima.

Pripyat's entire population of nearly 50,000 fled after Chernobyl's No. 4 reactor exploded in a devil's brew of caesium, strontium, iodine and plutonium on April 26, 1986.

"Pripyat was considered to be one of the best places to live in the Soviet Union," said Nikolai Fomin, a young Ukrainian who escorts visitors into the 30-kilometre (18-kilometre) exclusion zone around Chernobyl.

"It was considered a very happy place. It had good housing and schools, lots of young families, and the shops were filled with things you couldn't get elsewhere."

Today, trees thrust through the tarmac of the long-untended roads. Grass grows between cracks in pavements, where dry leaves click metallically in the sour wind. Apartment windows stare down on the streets like dark, lidless eyes.

"Everything here was new, everything was modern," said Fomin. "Pripyat was only 16 when it died."

Occasional visitors come by bus for a lightning tour, equipped with radiation dosimeters, hand wipes and water with which to decontaminate boots and clothing when they leave. But other than that, there is not a soul.

"Animals come, but they are not afraid of humans," said Fomin.

The city's swimming pool echoes to the crunch of broken glass and tile underfoot. In a fairground, the yellow gondolas of a Ferris wheel -- due to have been inaugurated on May Day in 1986 but never used -- creak in the wind. Dodgem cars rust at the spot where they stopped after their last ride.

In the main square, a rusting Soviet hammer and sickle overlook the Hall of Culture. In a back room of what seems to be a community hall are stacked placards of Lenin and Soviet leaders that had been prepared for the May 1 parade but were never used.

Resettling the people of Pripyat and other villages in the exclusion zone, sealing the crippled reactor, cleaning up the power plant, monitoring regions contaminated by fallout... the bill for Ukraine has been almost incalculable.

Even today, around five percent of its annual budget is devoted to Chernobyl-related benefits, including payment of a small sum, known darkly as "funeral money", to help people in contaminated regions buy clean food.

Belarus and Russia have also been badly hit. Together the three countries had relocated more than 330,000 people.

Up till 2005, the direct and indirect costs were "hundreds of billions of dollars", according to a 2005 report by the Chernobyl Forum, gathering those three countries, seven UN agencies and the World Bank.

In terms of the human toll and radioactive pollution, Fukushima is so far not remotely comparable with Chernobyl, said Malcolm Grimston, a nuclear specialist at Britain's Chatham House think tank.

But the duration of the evacuation zone around Fukushima remains unknown and the cleanup of the plant will surely last decades, he said.

The financial bill for Japan could eventually be comparable to Chernobyl, given the greater expense, disruption to business and higher cleanup standards compared to the former Soviet Union, he said.

"As a rule of thumb, the more developed the country, the higher the cleanup costs will be," said Grimston.

"However, it will be hard to separate out responsibility and costs between the earthquake, the tsunami and specific responsibility by TEPCO," the Tokyo Electric Power Co. (TEPCO), which operates the Fukushima No. 1 plant, he said.

In Tokyo, shares in TEPCO, have lost more than four-fifths of their value since the March 11 earthquake. On Tuesday, the price fell to a record low amid analysts' concerns it would face claims of more than 10 trillion yen (118 billion dollars/83 billion euros).

Source: Yahoo! News

Japan earthquake: Radioactive leak plugged at reactor

The concrete pit near Reactor No 2 was cracked by the quake

A leak of highly radioactive water into the Pacific Ocean from Japan's crippled Fukushima Daiichi nuclear plant has been stopped, its operator reports.

Tepco said it had injected chemical agents to solidify soil near a cracked pit that was the source of the leak.

Engineers have been struggling to stop leaks since the plant was damaged by the earthquake and tsunami on 11 March.

They are currently discharging less contaminated water into the sea so more radioactive water can be stored.

Since the earthquake knocked out cooling systems workers have been pumping water into reactors to cool fuel rods, but must now deal with waste water pooling in and below damaged reactor buildings.

Engineers also face a potential new problem of a build-up of hydrogen gas in one of the reactors at the six-unit plant. Tepco said it could inject nitrogen gas into the No 1 reactor to prevent an explosion.

Blasts caused by a build-up of hydrogen gas took place in three reactors in the aftermath of the earthquake.

'Water glass'

Plugging the leak from the pit in the No 2 reactor represents a measure of success for engineers at the plant, analysts say.

It is thought to have been the source of high levels of radiation found in seawater close to the plant.

In order to stem the leak, Tepco (the Tokyo Electric Power Co) injected ''water glass'', or sodium silicate, and another agent into the pit.

Desperate engineers had also used sawdust, newspapers and concrete in recent days to try to stop the escaping water.

The government's top spokesman said workers could not rule out other leaks at the reactor.

"Right now, just because the leak has stopped, we are not relieved yet," said Chief Cabinet Secretary Yukio Edano. "We are checking whether the leak has completely stopped, or whether there may be other leaks."

Meanwhile, engineers are continuing to pump some 11,500 tonnes of low-level radioactive seawater into the sea so the more highly contaminated water can be stored in waste buildings.

Officials said this water would not pose a significant threat to human health, but local fishermen have reacted angrily.

In a letter, the largest fisheries group accused the government of an "utterly outrageous" action that threatened livelihoods.

On Tuesday, elevated levels of iodine - about twice the legal limit for vegetables - were found in launce (a small fish) caught off Ibaraki prefecture to the south of Fukushima.

On Tuesday, Japan asked Russia for the use of a floating radiation treatment plant to tackle waste water.

Russia's nuclear agency Rosatom said it was awaiting answers to some questions before granting the request to lend the Landysh, known in Japanese as the Suzuran, which is used to decommission Russian nuclear submarines in the far eastern port of Vladivostok.

One of the world's largest liquid radioactive waste treatment plants, the Landysh treats radioactive liquid with chemicals and stores it in a cement form.

It can process 35 cubic metres of liquid waste a day and 7,000 cubic metres a year.

Fukushima update (6 April)
* Reactor 1: Damage to the core from cooling problems. Building holed by gas explosion. Radioactive water detected in reactor and basement, and groundwater. Hydrogen gas building up again.
* Reactor 2: Damage to the core from cooling problems. Building holed by gas blast. Highly radioactive water detected in reactor and adjoining tunnel. Crack identified in containment pit now plugged.
* Reactor 3: Damage to the core from cooling problems. Building holed by gas blast; containment damage possible. Spent fuel pond partly refilled with water after running low. Radioactive water detected in reactor and basement
* Reactor 4: Reactor shut down prior to quake. Fires and explosion in spent fuel pond; water level partly restored
* Reactors 5 & 6: Reactors shut down. Temperature of spent fuel pools now lowered after rising high

Source: BBC.co.uk

Record depletion of ozone recorded over Arctic: U.N.

GENEVA (Reuters) – Record loss of the ozone, the atmosphere layer that shields life from the sun's harmful rays, has been observed over the Arctic in recent months, the World Meteorological Organization said on Tuesday.
"Depletion of the ozone...has reached an unprecedented level over the Arctic this spring because of the continuing presence of ozone-depleting substances in the atmosphere and a very cold winter in the stratosphere," the WMO said in a statement.
Observations from the ground, balloons and satellites show that the region has suffered an ozone column loss of about 40 percent from the beginning of the winter to late March, according to the United Nations agency.
The highest ozone loss previously recorded over the Arctic, about 30 percent, occurred in several seasons over the past 15 years or so, according to a WMO spokeswoman.
"If the ozone depleted area moves away from the pole and toward lower latitudes one can expect increased ultraviolet (UV) radiation as compared to the normal for the season," WMO said, adding that the public should check their national UV forecasts.
But any increase in UV radiation over lower latitudes away from the Arctic -- which could affect parts of Canada, Nordic countries, Russia and Alaska in the United States -- would not be of the same intensity as one suffers in the tropics, it said.
UV-B rays have been linked to skin cancer, cataracts and damage to the human immune system. "Some crops and forms of marine life can also suffer adverse effects," the agency said.
Unlike over Antarctica, large ozone loss is not an annually recurring phenomenon in the Arctic stratosphere, where meteorological conditions vary much more each year.
The record ozone loss over the Arctic comes despite the "very successful" Montreal Protocol aimed at cutting production and consumption of ozone-destroying chemicals such as chlorofluorocarbons (CFCs) and halons, the WMO said.
The substances were once present in refrigerators, spray cans and fire extinguishers, but have been phased out.
Nevertheless, due to the long lifetimes of these compounds in the atmosphere, it will take several decades before their concentrations return to pre-1980 levels, the target laid down in the 1987 pact, it said.

Source: Yahoo! News

Japanese nuclear plant worker discusses choice to sacrifice his life

As Japan continues to grapple with catastrophic radiation leaks at the quake-damaged Fukushima Daichii nuclear complex, the plant's remaining workers have shown heroic dedication in the face of a task that amounts to a likely suicide mission.

The global audience following the Japanese nuclear drama has learned a little about these selfless heroes. But some of the most basic questions about them--who they are and what has motivated them to make the ultimate sacrifice--have gone unanswered. Now, however, the Agence France Press reporter Kimi De Freytas has published an interview with one of the Fukushima workers that sheds considerable light on how they understand their mission--and how they are holding up under under the extraordinary, mortal stress they are facing.

Hiroyuki Kohno, a 44-year-old plant worker who's been employed in the nuclear industry since he was a teenager, promptly answered the emergency call issued by his employer, a subcontractor for the Tokyo Electric Power Company. Shortly after last March's devastating earthquake and tsunami produced a power outage at the facility, Kohno's employers sent out an all-hands appeal via email.

"Attention. We would like you to come work at the plant. Can you?" De Freytas reports the email read. Kohno, who has worked at the Fukushima facility for the past decade, said he knew what the implications of heeding the call would be.

"To be honest, no one wants to go," Kohno told De Freytas. "Radiation levels at the plant are unbelievably high compared with normal conditions. I know that when I go this time, I will return with a body no longer capable of work at a nuclear plant."

Kohno told De Freytas that as a single man with no children, he felt obligated to answer the call and join the team that the media has dubbed the "Fukushima Fifty." Better that he face the risk, he explained, so as to spare his colleagues who have dependents counting on them. Besides, he added, the workers in the plant are his brothers and sisters, and he feels an allegiance to them.

"There's a Japanese expression: 'We eat from the same bowl.' These are friends I shared pain and laughter with. That's why I'm going," he explained to De Freytas.

Other workers among the Fukushima Fifty have apparently discussed the dire prospects ahead fairly openly. As the unidentified mother of a 32-year-old plant worker explained in a tearful phone interview with Fox News, "My son and his colleagues have discussed it at length and they have committed themselves to die if necessary to save the nation." Meanwhile, plant officials have sought to supplement the ranks of workers seeking to contain the spread of radioactive contamination from the facility with workers known as "jumpers"—contract employees who agree to complete designated tasks before fleeing in the hopes that they can shun sustained radioactive exposure. Workers in the "jumper" corps are being offered as much as $5,000 a day, Reuters reports—and many are still turning the offers down.

While the fate of Kohno and his fellow workers remains uncertain, their fellow citizens are already determined to commemorate their heroism.

Source: Yahoo! News

Big Dipper's Stars Pour on the Shine in Northern Sky

This sky map shows how the constellation Ursa Major, the Great Bear, appears in the night sky from mid-latitudes of North America at about 9 p.m. local time.
Credit: Starry Night Software

As the month of April begins, the northeastern U.S. states are experiencing an "Indian Winter" to — a lingering cold season well past the equinox — the way warm weather often hangs on into October, giving us Indian summer. And it seems that even the winter constellations are leaving us somewhat begrudgingly.

As darkness falls, the stars of Orion and his brilliant retinue are still readily visible well up in the southwest sky. And a month from now when it gets dark, those winter stars will still be visible, albeit hanging close to the western horizon.

Not too long thereafter, they will all be gone, reappearing in the eastern sky at the break of dawn in mid-summer.

A big dipper for spring

But as if to compensate for the loss of our brilliant winter stars, nature has provided us with a striking and well-known pattern to gaze at during the evening: the Big Dipper.

The seven stars of the Big Dipper are actually part of larger constellation, but can be easily recognized almost directly overhead at around midnight local time.

While many Americans recognize the ladle-shaped pattern as the Big Dipper, many other cultures regard as some kind of carriage or wheeled vehicle. In the United Kingdom, it's called the Plough.

Regardless of what these seven stars portray to various peoples, to Western civilization they have always been part of the larger Great Bear constellation, which we call Ursa Major.

The stars immediately to the west and south of the bowl of the Dipper form a pretty good stick figure of this creature. Only the bear’s tail, a longish one composed of the three stars that form the Dipper’s handle, is out of place since bears on Earth possess short, stubby ones.

Here’s an aside to our Internet friends who live in below the equator in the Southern Hemisphere: This is the time of year that you’ll get your best views of Ursa Major and the Big Dipper. But instead of appearing overhead, as they do in the Northern Hemisphere, the star patterns are oriented in the northern part of the sky. So the farther south one goes, the lower in the north the star patterns will get.

Still in view far south

Probably the most unusual view of the Big Dipper that I ever had was when I led a Halley’s Comet tour to Easter Island in April 1986.

From a latitude of 27.1 degrees south, I could see the Dipper hovering just above the northern horizon – upside down! Interestingly, back home in the fall, I can see the Dipper sitting at a similar distance above my local northern horizon, but right-side-up.

The upside-down Dipper, however, can now be glimpsed as far south as 30 degrees south latitude, which includes many far-southerly locations, such as Johannesburg, South Africa; Asuncion, Paraguay; and Sao Paulo, Brazil.

On page 24 of what I think is one of the very best guides to the constellations, “The Stars – A new way to see them” (available from Houghton-Mifflin Co., Boston), author H.A. Rey sketched a kangaroo with a baby joey in her pouch. The caption reads: “The Dipper? Never seen it …"

However, much of Australia can also see the Dipper now, as about three-quarters of the land area of that country is located above latitude 30 degrees south. But unfortunately, most of that country’s population is distributed below that imaginary line!

Now about that tail …

What is really remarkable about the Big Dipper stars is that in one way or another they’ve always comprised a bear to widely separated early peoples – not only to Old World ancients but to New World Indian tribes as well.

But over the years, in pointing out the Great Bear to audiences either in the Space Theater of New York’s Hayden Planetarium or under the real night sky, I have had to spend a minute or two trying to explain away the Bear’s unusually long tail. Perhaps the most common reason given is the one attributed to the British humorist and poet, Thomas Hood (1799-1845):

Hood wrote (with original spellings): “Imagine that Jupiter, fearing to come too nigh unto her teeth, layde holde on her tayle, and thereby drewe her up into the heaven; so that shee of herself being very weightie, and the distance from the Earth to the heavens very great, there was a great likelihood that her tayle must stretch. Other reason know I none.”

Source: Space.com

NASA: Mysterious Fireball Season Set to Light Up Night Sky

Spring has arrived in the Northern Hemisphere, which means that birds are chirping, flowers are blooming — and fireballs are lighting up the sky, NASA says.

For some mysterious reason, the number of fireballs — dramatic meteors that blaze brighter than any planet when they burn up in Earth's atmosphere — peaks at this time of year.

"Spring is fireball season," said Bill Cooke, of NASA's Meteoroid Environment Center, in a statement. "For reasons we don't fully understand, the rate of bright meteors climbs during the weeks around the vernal equinox." [Spectacular Leonid Meteor Photos]

Most of the year, a person gazing skyward from dusk to dawn can expect to see about 10 random — or "sporadic" — fireballs, researchers said. These bright shooting stars result when space rocks — fragments of broken asteroids and decaying comets — plow into Earth's atmosphere.

But in spring, the number of sporadic fireballs climbs by 10 to 30 percent.

"We've known about this phenomenon for more than 30 years," Cooke said. "It's not only fireballs that are affected. Meteorite falls — space rocks that actually hit the ground — are more common in spring as well."

The reasons for the surge of fireballs and meteorites remain mysterious — especially considering that the number of ordinary meteors peaks in the Northern Hemisphere's autumn season. At that time of year, Earth seems to sweep up a higher number of space rocks, and skywatchers can see dozens of normal-brightness meteors per night, researchers said.

"Autumn is the season for sporadic meteors," Cooke said. "So why are the sporadic fireballs peaking in spring? That is the mystery."

Some scientists think that the meteoroid population along Earth's orbit might vary with time, with a peak in big fireball-producing space rocks coming around spring and early summer. But more research needs to be done.

"We probably won't know the answer until we learn more about their orbits," said meteoroid expert Peter Brown of the University of Western Ontario.

Cooke is working to do just that. He's setting up a network of smart meteor cameras around the country to photograph fireballs and triangulate their orbits. Networked observations of spring fireballs could ultimately reveal their origin, researchers said.

But you don't have to know where fireballs come from to appreciate them. So go outside, crane your neck up on a clear night, and enjoy some of the blazing heralds of spring.

Source: Space.com

Sun Fades Away in Spectacular Eclipse Photo

A powerful NASA solar observatory has snapped an amazing view of the sun, a photo that shows the star partially obscured by the Earth.

The photo, obtained Tuesday (March 29) by NASA's Solar Dynamics Observatory, was taken during the spacecraft's so-called eclipse season – a period of the year when the satellite slips behind Earth for up to 72 minutes of every day.

Sometimes, as the spacecraft swings behind the Earth, the probe is able to catch views of the planet as it blocks the sun. The result is an eerie view in which the sun's bright disk gradually fades from view.

The image is a striking departure from other SDO photos that show the moon eclipsing the sun, known as lunar transits, which cut a crisp shadowy bite out of the star. [Amazing New Sun Photos From Space]

"Earth's shadow has a variegated edge due to its atmosphere, which blocks the sun light to different degrees depending on its density," NASA scientists explained in a photo description. "Also, light from brighter spots on the sun may make it through, which is why some solar features extend low into Earth's shadow."

NASA's Solar Dynamics Observatory experiences two eclipses seasons every year. The observatory was launched last year and is equipped with several high-definition cameras to beam back stunning views of the sun in different wavelengths.

The $850 million solar observatory is expected to last five years.

Source: Space.com

Scarred by Comets: Rings of Saturn and Jupiter Show Signs of Impacts

Strange formations in the rings around Saturn and Jupiter are the telltale marks of dramatic comet impacts that occurred in the last few decades, two new studies suggest.

The newly discovered ripples show that bits of a broken-up comet likely plowed through Saturn's C ring, one of many around the planet, back in 1983 — an event that went undetected by astronomers at the time. Similar structures appeared in Jupiter's gossamer rings in 1994, when the comet Shoemaker-Levy 9 slammed into that gas giant's southern hemisphere, researchers said.

The new findings show that rings can act as historical documents, chronicling the violent pasts of their parent planets, researchers said. [Photos: Jupiter Struck by Space Rock Again]

"We may have a new record of the bombardment history of the outer solar system recorded in these rings," said Matt Hedman of Cornell University, lead author of one of the studies and a co-author on the other one. "It just shows you again how rings can be useful for studying the outer solar system."

Ripples in the rings

The researchers used observations from several different NASA spacecraft to detect the ring ripples.

By poring over data and images the Cassini probe took in August 2009 — when the sun illuminated Saturn's rings edge-on — Hedman and his team noticed waves extending across the planet's entire C ring. These formations have an amplitude of 6.6 to 66 feet (2 to 20 meters), and a wavelength of 18.6 to 49.7 miles (30 to 80 kilometers), researchers said.

In the other study, researchers led by Mark Showalter of the SETI (Search for Extraterrestrial Intelligence) Institute saw two similar patterns in Jupiter's main ring. The ripples showed up in images taken by the Galileo spacecraft in 1996 and 2000, and by the New Horizons probe in 2007.

After characterizing and analyzing the waves, the researchers determined that they formed after the rings of the two giant planets were knocked slightly off-kilter in the past several decades. [Gallery: The Rings and Moons of Saturn]

Over time, the intially tilted ring sheets spawned the ripples through a shearing process, as the ring particles orbited Saturn and Jupiter.

"It's just a winding spiral that gets wound up more and more tightly as time goes on, and eventually it looks like a vertical corrugation," Hedman told SPACE.com. The ripples should eventually dissipate, he added, though that may take a while — perhaps a few hundred years for the Saturn formation.

The scientists think they know how the rings got tilted in the first place. Clouds of broken-up comet particles likely smashed into the planets' rings in separate events, pushing the structures slightly out of whack, researchers said.

Broken-up comet crumbs

Sophisticated modeling work, along with careful study of the ripples' properties, told the researchers a lot about how and when the strange structures likely formed and evolved.

They were able to determine, for example, that the Saturn C-ring tilt probably resulted from a collision with a debris cloud with a mass between 220 billion to 22 trillion pounds (100 billion to 10 trillion kilograms). That's roughly as much material as a 0.6-mile-wide (1 km) comet contains.

And they figured out that the impact with the C ring happened in 1983, probably around August or September. Saturn's D ring became inclined at the same time (researchers noticed ripples in that structure back in 2007).

Jupiter's main ring, on the other hand, was likely tilted twice, with the most dramatic impact occurring sometime between July and October 1994.

This latter date range coincides with a famous comet smash on Jupiter — the impact of comet Shoemaker-Levy 9, which barreled into the planet from July 16 through July 20, 1994.

"If the [Jupiter] tilting event doesn't have something to do with Shoemaker-Levy 9, that would be very surprising," Hedman said.

The most parsimonious explanation is that a similar event produced Saturn's ring tilt, too, he added — especially since alternative theories aren't nearly as persuasive.

"We've considered other ideas, but thus far we haven't come up with anything that looks as plausible," Hedman said.

Big chunks of Shoemaker-Levy 9 likely didn't pass through Jupiter's main ring on their suicide path into the planet. Rather, clouds of smaller particles — formed when the planet's gravity tore the comet apart on previous passes — are likely to blame.

The same goes for the 1983 Saturn event, as well as the other, as-yet mysterious Jupiter impact that produced the main ring's secondary pattern, researchers said.

"You need a cloud that hits a broad region of the rings," Hedman said. A big solid piece would just punch holes in the rings, he added. "It won't produce the broad-scale tilt."

The researchers report their results in the April 1 issue of the journal Science.

Outer solar system's violent past

The rings of Jupiter and Saturn serve as a sort of chronicle of the bombardment history of those two giant planets, according to the new studies. The rings could help astronomers better understand how many comets may be racing around the sun.

"This could potentially provide some useful constraints on the number of small bodies running around the outer solar system," Hedman said.

The 1983 comet crash suggests that such impacts may be more common than researchers had previously believed.

"The outer solar system may be a more dynamic place than we sometimes give it credit for," Hedman said. "Maybe these events — where something crashes into the giant planets — aren't as rare as we might have originally thought."

Source: http://www.space.com/11269-comet-impacts-saturn-jupiter-rings.html

Saturn Returns to Earth's Evening Sky

The ringed planet Saturn is back in the evening sky.

Saturn reaches opposition – the time when it is exactly opposite the sun in the sky – on the night of April 3 and early morning of April 4. One side effect of this is that Saturn is now in the sky all night long, rising in the east as the sun sets, and then setting in the west when the sun rises.

As the most distant of the naked-eye planets (Uranus technically can be seen with the naked eye, but it takes a sharp eye and knowledge of its exact location), Saturn gets the least sunlight and so reflects the least amount of light back to Earth.

As a result, Saturn is not as bright as the other naked-eye planets. This sky map of Saturn shows where to find the ringed planet in the evening sky.

How to spot Saturn

Here's another way to find Saturn: Follow the arc of the Big Dipper's handle to Arcturus and then speed on to Spica. Make a sharp left at Spica and there you will find Saturn.

Almost every amateur astronomer remembers Saturn as one of their first views through the telescope. Although much smaller than most people expect from the pictures they’ve seen, Saturn with its rings is a uniquely beautiful and captivating sight.

Seeing the rings requires a telescope magnifying at least 20 times, but Saturn can handle just about any magnification above that.

For the last two years, most people have been disappointed because Saturn's famous rings have been "edge on" to Earth. Saturn’s rings are tilted towards a particular point in the sky so that as Saturn travels in its orbit around the sun, sometimes the rings are presented towards us and at other times they disappear when the Earth is in the same plane as the rings.

Having been next to invisible for the past two years, the rings are now revealing their northern surface towards the Earth.

In a telescope, look for the dark division between the main inner and outer rings. This is named Cassini’s Division after 17th century astronomer Giovanni Domenico Cassini, who first discovered it.

Search for Saturn's moons

Cassini also discovered Saturn's four brightest moons, all of which can be seen in a 4-inch telescope. He was particularly interested in the moon Iapetus which showed interesting variations as it moves around the planet.

Cassini correctly surmised was due to one hemisphere being darker than the other. This was recently confirmed by NASA's Cassini spacecraft, which is named for Giovanni, and is currently in orbit around Saturn.

Saturn’s largest moon, Titan, is the only moon in the solar system with an appreciable atmosphere and is readily visible in any small telescope. The smaller moons come into view with larger telescopes.

Source: http://www.space.com/11262-saturn-skywatching-tips-evening-sky.html

Japan nuke workers ‘have committed themselves to die if necessary’

The mother of one of the atomic "samurai" working to bring Japan's stricken nuclear plant under control has said her son and his colleagues expect to die as a result of their efforts. Meanwhile, there are reports that additional workers are being offered big money to dash into the radiation-drenched heart of the Fukushima Daiichi plant, perform a job, then withdraw.

In a phone interview with Fox News, the tearful mother of a 32-year-old worker said: "My son and his colleagues have discussed it at length and they have committed themselves to die if necessary to save the nation."

"He told me they have accepted they will all probably die from radiation sickness in the short term or cancer in the long term," the woman added.

"They know it is impossible for them not to have been exposed to lethal doses of radiation."

The woman did not give her name, because she said the workers had been asked by management not to speak publicly about their ordeal, in order to minimize panic.

There are also indications that the workers aren't being provided with some crucial safety equipment. Japan's interior minister said that not all of the workers were given lead sheeting to protect themselves from the floor--which may be contaminated by radiation--while sleeping.

"My son has been sleeping on a desk because he is afraid to lie on the floor. But they say high radioactivity is everywhere and I think this will not save him," said the mother.

In another bleak sign, there are reports of additional workers being offered up to $5,000 a day to act as "jumpers"--so called because they "jump" into highly radioactive areas to quickly perform a task before fleeing with minimal exposure. But even at those rates, many candidates are turning the work down, Reuters reports.

"My company offered me 200,000 yen ($2,500) per day," one subcontractor in his 30s told a reporter."Ordinarily I'd consider that a dream job, but my wife was in tears and stopped me, so I declined."

And Ryuta Fujita, 27, told the Tokyo Shimbun newspaper he was offered $5,000 to go into Reactor 2, but likewise declined.

"I hear that guys older than 50 are being hired at high pay," Fujita said. "But I'm still young, and radiation scares me. I don't want to work in a nuclear plant again."

Last week two workers in Reactor 3 were taken to hospital after their feet were exposed to 170-180 millisieverts of radiation. The average dose for a worker at a nuclear plant is 50 millisieverts over 5 years.

Because so few workers want to venture into the plant, it's proving hard for TEPCO, that company that runs it, to assess whether efforts to cool the fuel rods are working, or even to fully diagnose the problems.

Robots are usually used for this type of work, but Fukushima's interior is so filled with debris that it's difficult for robots to operate there.

Source: http://news.yahoo.com/s/yblog_thelookout/20110401/ts_yblog_thelookout/japan-nuke-workers-have-committed-themselves-to-die-if-necessary