Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.
By: Susie77, 9:04 PM GMT on August 30, 2012
From Science at NASA
The Radiation Belt Storm Probes
August 30, 2012: Since the dawn of the Space Age, mission planners have tried to follow one simple but important rule: Stay out of the van Allen Belts. The two doughnut-shaped regions around Earth are filled with “killer electrons,” plasma waves, and electrical currents dangerous to human space travelers and their spacecraft. Lingering is not a good idea.
So much for the old rules. NASA has launched two spacecraft directly into the radiation belts--and this time they plan to stay a while.
A new ScienceCast video explores the mysteries of the Van Allen Belts. Play it
NASA's Radiation Belt Storm Probes blasted off from Cape Canaveral on August 30th, 2012. Bristling with sensors, the heavily-shielded spacecraft are on a 2-year mission to discover what makes the radiation belts so dangerous and so devilishly unpredictable.
"We've known about the Van Allen Belts for decades yet they continue to surprise us with unexpected storms of 'killer electrons' and other phenomena," says mission scientist David Sibeck, "The Storm Probes will help us understand what's going on out there."
When the radiation belts were discovered in 1958, they upended orthodox ideas. Most people assumed the space around Earth was empty. America's first satellite, Explorer 1, proved otherwise. The tiny spacecraft was equipped with a Geiger tube for counting energetic protons and electrons. Circling Earth, Explorer 1 found so many charged particles that the counter registered off-scale most of the time.
Back in the 1950s the radiation belts had little effect on ordinary people. Today they are crucial to our high-tech society. Hundreds of satellites used for everything from weather prediction to GPS to television routinely skim the belts, subjecting themselves to energetic particles that can damage solar panels and short-circuit sensitive electronics. During geomagnetic storms when the belts are swollen by solar activity, whole fleets of satellites can be engulfed, imperiling the technological underpinnings of daily life on the planet below.
"The Radiation Belt Storm Probes directly address these down-to-Earth problems," says Lika Guhathakurta, the lead program scientist of NASA's Living with a Star Program, which manages the mission. "RBSP is a unique mix of pure science and practical application."
One of the biggest mysteries of the radiation belts is the crazy way they react to solar storms.
"Almost anything can happen," says Sibeck.
When a storm cloud from the sun hits the radiation belts, they often respond in counterintuitive ways. One possible outcome is that the radiation belts fill with energetic particles such as the potent "killer electrons" that worry mission planners. However, just as often the opposite happens. A solar storm can cause the belts to lose their killer particles, temporarily making them a safer place. And sometimes nothing happens! The belts remain completely unchanged.
"The problem is, there is no unified idea of what phenomena are most important inside the belts," says Sibeck. He describes attending scientific conferences on the subject: "If there are 100 people at a meeting, there will be 100 different answers for every question. How are killer electrons energized? Some say plasma waves do it; others point to solar wind shocks; others favor diffusion. The list goes on and on."
Researchers hope RBSP will narrow the possibilities. During storms, the probes can sample electric and magnetic fields, count the number of energetic particles, and detect plasma waves of many frequencies. The inner workings of the Van Allen Belts will be an open book to the two spacecraft, providing data for predictive models that tell forecasters when it’s safe to enter the belts, perform spacewalks, and operate sensitive electronics.
“The Van Allen Belts are part of our home in space,” adds Guhathakurta. “RBSP will help us learn how to live there.”
So much for the old rules, indeed.
Author: Dr. Tony Phillips| Production editor: Dr. Tony Phillips | Credit: Science@NASA
By: Susie77, 4:57 PM GMT on August 29, 2012
From Space dot com
NASA Captures Amazing View of Tropical Storm Isaac at Night
A NASA satellite captured a spectacular photo of what is now Hurricane Isaac from space, a nighttime view showing the then-tropical storm's clouds lit up by moonlight as it approached the U.S. Gulf Coast.
NASA's Suomi-NPP weather tracking satellite recorded the amazing nighttime photo of Isaac just after midnight on Tuesday (Aug. 28). The bright city lights of New Orleans, Houston and Tampa, Fla., can be easily identified, but the photo also includes lights from cities all along the Gulf Coast, Florida and the southeast U.S. coast.
"The image was acquired just after local midnight by the VIIRS 'day-night band,' which detects light in a range of wavelengths from green to near-infrared and uses light intensification to enable the detection of dim signals," NASA officials explained in an image description. "In this case, the clouds of Isaac were lit by moonlight."
Hurricane Isaac is currently a Category 1 hurricane and made two landfalls late Tuesday in Louisiana. As of 10 a.m. EDT (1400 GMT) today (Aug. 29), Isaac is battering Louisiana and neighboring states with drenching rains and maximum sustained winds of 75 miles per hour (120 kilometers per hour), according to the latest National Hurricane Center update.
NASA and the National Oceanographic and Atmospheric Administration are using several satellites to track Hurricane Isaac as it slowly moves across the Gulf Coast.
"Flooding is a big threat from Isaac because of its slow movement, and because it is drawing a lot of energy from the warm waters of the Gulf of Mexico," NASA spokesman Rob Gutro wrote in a hurricane update. "Isolated tornadoes are also possible as Isaac continues moving inland."
By: Susie77, 6:12 PM GMT on August 27, 2012
From Science @ NASA
Wide Awake in the Sea of Tranquillity
Neil Armstrong was supposed to be asleep. The moonwalking was done. The moon rocks were stowed away. His ship was ready for departure. In just a few hours, the Eagle's ascent module would blast off the Moon, something no ship had ever done before, and Neil needed his wits about him. He curled up on the Eagle's engine cover and closed his eyes.
But he could not sleep.
Neither could Buzz Aldrin. In the cramped lander, Buzz had the sweet spot, the floor. He stretched out as much as he could in his spacesuit and closed his eyes. Nothing happened. On a day like this, sleep was out of the question.
Above: Apollo 11 Earthrise. [More]
July 20, 1969: The day began on the farside of the Moon. Armstrong, Aldrin and crewmate Mike Collins flew their spaceship 60 miles above the cratered wasteland. No one on Earth can see the Moon's farside. Even today it remains a land of considerable mystery, but the astronauts had no time for sight-seeing. Collins pressed a button, activating a set of springs, and the spaceship split in two. The half named Columbia, with Collins on board, would remain in orbit. The other half, the Eagle, spiraled over the horizon toward the Sea of Tranquillity.
"You are Go for powered descent," Houston radioed, and the Eagle's engine fired mightily. The bug-shaped Eagle was so fragile a child could poke a hole through its gold foil exterior. Jagged moonrocks could do much worse. So when Armstrong saw where the computer was guiding them--into a boulder field-足he quickly took control. The Eagle pitched forward and sailed over the rocks.
Meanwhile, alarms were ringing in the background.
"Program alarm," announced Armstrong. "It's a 1202." The code was so obscure, almost no one knew what it meant. Should they abort? Should they land? "What is it?" he insisted.
Scrambling back in Houston, a young engineer named Steve Bales produced the answer: The radar guidance system was pestering the computer with too many interruptions. No problem. "We've got you..." radioed Houston. "We're Go on that alarm."
And on they went. Things, however, were not going exactly as planned. The Sea of Tranquillity was supposed to be smooth, but it didn't look so smooth from the cockpit of the Eagle. Armstrong scanned the jumbled mare for a safe place to land. "60 seconds," radioed Houston. "30 seconds." Mission control was hushed as the telemetry came in. Soon, too soon, the ship would run out of fuel.
Capcom later claimed the "boys in mission control were turning blue" when Armstrong announced "I [found] a good spot." As for Armstrong, his heart was thumping 156 beats per minute according to bio-sensors. The fuel gauge read only 5.6% when the Eagle finally settled onto the floor of the Sea of Tranquillity.
Houston (relieved): "We copy you down, Eagle."
Armstrong (coolly): "Houston, Tranquility Base here. The Eagle has landed."
Immediately, they prepared to leave. This was NASA being cautious. No one had ever landed on the Moon before. What if a footpad started sinking into the moondust, or the Eagle sprung a leak? While Neil and Buzz made ready to blast off, Houston read the telemetry looking for signs of trouble. There were none, and three hours after touchdown, finally, Houston gave the "okay." The moonwalk was on!
At 9:56 p.m. EDT, Neil descended the ladder and took "one small step" (left foot first) into history. From the shadow of the Eagle, he looked around: "It has a stark beauty all its own--like the high desert of the United States." Houston reminded him to gather the "contingency sample," and Neil put some rocks and soil in his pocket. If, for any reason, the astronauts had to take off in a hurry, scientists back on Earth would get at least a pocketful of the Moon for their experiments.
Soon, Buzz joined him. "Beautiful view!" he exclaimed when he reached the lander's broad footpad. "Isn't that something!" agreed Armstrong. "Magnificent sight out here."
"Magnificent desolation," said Aldrin.
Those two words summed up the yin-yang of the Moon. The impact craters, the toppled boulders, the layers of moondust--it was utterly alien. Yet Tranquillity Base felt curiously familiar, like home. Later Apollo astronauts had similar feelings. Maybe this comes from staring at the Moon so often from Earth. Or maybe it's because the Moon is a piece of Earth, spun off our young planet billions of years ago. No one knows; it just is.
Truly, much of the scene was weird. The airless landscape jumped out at the astronauts with disconcerting clarity and, as a result, the horizon felt unnaturally close. Worse yet, the whole world seemed to curve, a side-effect of the Moon's short thousand-mile radius. "Distances [here] are deceiving," noted Aldrin.
The sky was equally baffling. Although the Eagle had landed on a bright lunar morning, the sky was as black as midnight. An astronomer's paradise? No. Not a single star was visible. The glaring, sunlit ground ruined the astronaut's night vision. Only Earth itself was bright enough to be seen, luminous blue and white, hanging overhead.
Armstrong was particularly fascinated by moondust, which he kicked and scuffed with his boots. On Earth, kicking dust makes a little cloud in the air--but there is no air on the Moon. "When you kick the surface, [the dust goes out in] a little fan which, to me, is in the shape of a rose petal," recalls Armstrong. "There's just a little ring of particles--nothing behind 'em--no dust, no swirl, no nothing. It's really unique."
Enough of that. It was time for work.
Almost forgotten in Apollo lore are the checklists sewn to the forearms of the spacesuits. These "honey-do" memos from NASA were jam-packed with activities--from inspecting the lander to deploying the TV to collecting samples. Some of the tasks were as detailed as bending over and reporting to Mission Control how it went. They had a lot to do.
Neil and Buzz deployed a solar wind collector, a seismometer and a laser retroreflector. They erected a flag and uncovered a plaque proclaiming, "We came in peace for all mankind." They took the first interplanetary phone call--"I just can't tell you how proud we all are," said President Nixon from the Oval Office. They collected 47 lbs of moon rocks and took 166 pictures. Check. Check. Check.
Finally, after two and a half busy, exhilarating hours, it was time to go. The checklist continued: Climb back in the Eagle. Stow the rocks. Prepare the ship for departure (again). Eat dinner: Beef stew or cream of chicken soup. And finally, sleep.
That was the limit. "You just are not going to get any sleep while you're waiting [for liftoff]," Aldrin said after the mission.
The Eagle was not a sleepy place. The tiny cabin was noisy with pumps and bright with warning lights that couldn't be dimmed. Even the window shades were glowing, illuminated by intense sunshine outside. "After I got into my sleep stage and all settled down, I realized there was something else [bothering me]," said Armstrong. The Eagle had an optical telescope sticking out periscope-style. "Earth was shining right through the telescope into my eye. It was like a light bulb."
To get some relief, they closed the helmets of their spacesuits. It was quiet inside and they "wouldn't be breathing all the dust" they had tramped in after the moon walk, said Aldrin. Alas, it didn't work. The suit's cooling systems, so necessary out on the scorching lunar surface, were too cold for sleeping inside the Eagle. The best Aldrin managed was a "couple hours of mentally fitful drowsing." Armstrong simply stayed awake.
When the wake-up call finally came,
"Tranquility Base, Tranquility Base, Houston. Over."
Armstrong answered with alacrity,
"Good morning, Houston. Tranquility Base. Over."
It was time to go home for a good night's sleep.
By: Susie77, 12:56 AM GMT on August 26, 2012
From L.A. Times
Neil Armstrong’s loved ones said they were “heartbroken” to share the news that the former astronaut and first person to step foot on the moon had died Saturday of complications from heart surgery. Armstrong was 82.
“Neil was our loving husband, father, grandfather, brother and friend,” the family statement said. “As much as Neil cherished his privacy, he always appreciated the expressions of goodwill from people around the world and from all walks of life.
“While we mourn the loss of a very good man, we also celebrate his remarkable life and hope that it serves as an example to young people around the world to work hard to make their dreams come true, to be willing to explore and push the limits, and to selflessly serve a cause greater than themselves.
“For those who may ask what they can do to honor Neil, we have a simple request. Honor his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink.”
Thank you for your service, may you R.I.P., Cdr. Armstrong. You truly were a hero.
By: Susie77, 4:59 PM GMT on August 20, 2012
Normally I stay far away from anything political here, unless it is science- or weather-related. That being said, I do want to apologize in advance to everyone offended by the idiotic remarks of our congressman, Todd Akin (R-MO). Here is science to explain just why he is an idiot. Whether you vote R, I, or D -- please vote for those who respect and understand science. Thank you.
From Pregnancy Myths
When a viable sperm penetrates a viable egg inside a woman's reproductive tract, the result is a fertilized egg that can then implant in the uterus. That fact of life is consistent regardless of how that sperm and egg met up, including whether or not the sperm was ejaculated during rape.
That may be news to Rep. Todd Akin from Missouri who told a local television station, in explaining his stance that abortion should not be allowed even in the case of rape: "If it's a legitimate rape, the female body has ways to try to shut that whole thing down."
"Physiologically, if the sperm is in the vagina, a pregnancy can occur, regardless of the circumstances of how that sperm got there," said Dr. Melisa Holmes, an ob-gyn and founder of Girlology, an organization that promotes healthy sexuality and communication in families.
And though the anti-abortion Republican says he "misspoke," Holmes says that Akin's remark also suggests that some rapes are not "legitimate," and this continues a harmful misconception about violence against women.
"A rape is a rape, and a woman has the same physical and emotional consequences whether she's raped by a stranger in a dark alley or someone she's known for five years," Holmes told LiveScience. "That's one of those misperceptions that gets perpetuated and unfortunately affects women in a bad way — 'Were you really raped, or were you at fault for part of it?'"
Perhaps Akin is correct in thinking it's not the easiest of tasks to get pregnant; that's why men don't ejaculate just one sperm and instead release nearly 100 million sperm. (Men who have fewer than 20 million sperm per milliliter of semen may have difficulty conceiving, according to a WebMD article.) That's because few sperm survive the grueling journey from the vagina to the fallopian tubes where they can meet up with an egg. Even for those that make it, only the healthiest will penetrate, and fertilize, the egg. [11 Odd Facts About the Pregnant Body]
Still, of the 6.7 million pregnancies in the United States every year, about half are unintended, according to the Guttmacher Institute.
The chance of getting pregnant from one event of unprotected sexual intercourse is 5 percent on average, according to the Rape, Abuse & Incest National Network (RAINN).
And according to research by Holmes and her colleagues published in 1996 in the American Journal of Obstetrics & Gynecology, that same rate applies to rape victims, though it's tricky to compare these different populations.
"Rape-related pregnancy occurs with significant frequency," the study researchers wrote in their journal article. "It is a cause of many unwanted pregnancies, and is closely linked with family and domestic violence."
In the study, Holmes and her colleagues, followed more than 4,000 American adults over a three-year period. Nationally, they found rape-related pregnancy rate was 5 percent among women of reproductive age, 12 to 45, meaning about 32,000 pregnancies result from rape each year, they concluded. Among 34 cases of rape-related pregnancy that they looked at closely, 32 percent of women maintained the pregnancy and kept the infant, 50 percent underwent an abortion, nearly 6 percent placed the baby up for adoption and nearly 12 percent had a miscarriage.
At the end of the day, Holmes said of Akin's comments, "It's just simple lack of education into the human body," adding that "the reproductive system is going to respond in the same way whether it's rape, or you're madly in love with someone. It's tubes and pipes and sperm and eggs, and there's nothing that will stop that process."
By: Susie77, 12:22 PM GMT on August 06, 2012
Source: Jet Propulsion Laboratory
NASA Lands Car-Size Rover Beside Martian Mountain
PASADENA, Calif. -- NASA's most advanced Mars rover Curiosity has landed on the Red Planet. The one-ton rover, hanging by ropes from a rocket backpack, touched down onto Mars Sunday to end a 36-week flight and begin a two-year investigation.
The Mars Science Laboratory (MSL) spacecraft that carried Curiosity succeeded in every step of the most complex landing ever attempted on Mars, including the final severing of the bridle cords and flyaway maneuver of the rocket backpack.
"Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars. Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars -- or if the planet can sustain life in the future," said NASA Administrator Charles Bolden. "This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030's, and today's landing marks a significant step toward achieving this goal."
Curiosity landed at 10:32 p.m. Aug. 5, PDT, (1:32 a.m. EDT Aug. 6) near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater. During a nearly two-year prime mission, the rover will investigate whether the region ever offered conditions favorable for microbial life.
"The Seven Minutes of Terror has turned into the Seven Minutes of Triumph," said NASA Associate Administrator for Science John Grunsfeld. "My immense joy in the success of this mission is matched only by overwhelming pride I feel for the women and men of the mission's team."
Curiosity returned its first view of Mars, a wide-angle scene of rocky ground near the front of the rover. More images are anticipated in the next several days as the mission blends observations of the landing site with activities to configure the rover for work and check the performance of its instruments and mechanisms.
"Our Curiosity is talking to us from the surface of Mars," said MSL Project Manager Peter Theisinger of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The landing takes us past the most hazardous moments for this project, and begins a new and exciting mission to pursue its scientific objectives."
Confirmation of Curiosity's successful landing came in communications relayed by NASA's Mars Odyssey orbiter and received by the Canberra, Australia, antenna station of NASA's Deep Space Network.
Curiosity carries 10 science instruments with a total mass 15 times as large as the science payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking elemental composition of rocks from a distance. The rover will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover.
To handle this science toolkit, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. The Gale Crater landing site places the rover within driving distance of layers of the crater's interior mountain. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.
The mission is managed by JPL for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. JPL is a division of the California Institute of Technology in Pasadena.
For more information on the mission, visit: http://www.nasa.gov/mars and http://marsprogram.jpl.nasa.gov/msl .
Follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity
And http://www.twitter.com/marscuriosity .
Guy Webster / D.C. Agle 818-354-6278 / 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
firstname.lastname@example.org / email@example.com
Dwayne Brown 202-358-1726
NASA Headquarters, Washington
By: Susie77, 7:13 PM GMT on August 01, 2012
From Sky and Telescope
Tour August's Sky by Eye and Ear!
Ask a skywatcher what’s special about August, and the response will likely be the Perseid meteor shower. These “shooting stars” are caused when little bits of grit shed by Comet Swift-Tuttle slam into our atmosphere. Every August, we plow right through this stream of dusty debris.
Evening sky in mid-August
In mid-August the crescent Moon joins two bright planets and a bright star low in the west after sunset.
Sky & Telescope illustration
If you manage to stay up until the hours before dawn, you’ll be rewarded with sightings of Jupiter, dazzling Venus, and, around midmonth, Mercury lurking down by the eastern horizon about an hour before sunrise.
Meanwhile, Mars and Saturn are the two bright planets low in the evening sky. They're joined by Spica, and all three are nearly the same brightness.
This will be a busy month for stargazing, and to get a personally guided tour you can download August's 7-minute-long audio sky tour. It's a 7-MB MP3 file. Enjoy!
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