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Category Archives: Space

One Ring to Bring Them All: Eclipse Enchants

Ever see ringlets of sunlight playing in the shadows of a tree or a fiery ring of light in the sky? These incredible effects are the results of an annular solar eclipse like the one that occurred when the moon passed directly between the sun and Earth on Sunday, May 20, 2012. The event was viewable from Japan all the way across the Pacific Ocean to midway through the United States.

Because the moon travels on a slightly tilted orbit compared to the plane of Earth’s orbit around the sun, eclipses do not occur every time the moon comes between the sun and Earth. However, there are two points or “nodes” when the moon does pass through this plane. If either of these nodes coincides with a new moon (when the sun is illuminating only its far side), a solar eclipse will occur. If a node is reached during a full moon, Earth will block the sun’s light, casting a shadow onto the moon causing a lunar eclipse.

An annular eclipse occurs when the moon is too far away from us to completely cover the disk of the sun. This results in an annularity: the ring-shaped outline of the sun that can be seen surrounding the dark new moon. Because of the surreal look of the “ring of fire,” annular eclipses are some of the most impressive celestial events visible from Earth.

This eclipse passed over some of the U.S.’s most famous national parks with the full annularity visible from 33 parks, while an additional 125 parks witnessed a partial eclipse. The NASA Lunar Science Institute (NLSI) at NASA’s Ames Research Center, Moffett Field, Calif., and the National Parks Service took advantage of this rare event and joined forces to facilitate safe viewings for as many people as possible.

Several NLSI scientists traveled to the Grand Canyon National Park and used the superimposition of our two most prominent celestial objects as an opportunity to explain to several thousand visitors about some of NASA’s past, current and future projects relating to the sun and moon. These include the Lunar Atmosphere and Dust Environment Explorer (LADEE), which will orbit the moon in order to characterize its atmosphere and the lunar dust environment, and the Interface Region Imaging Spectrograph, (IRIS) ,which will make detailed measurements of the flow of energy and plasma through the sun’s atmosphere and heliosphere.

The NLSI team gave presentations to three full-house audiences in the park’s theater and hosted an exhibit in its main visitor center. Samples of moon and Mars rocks and meteorites that people could handle were on display, as well as a model of a LADEE.

“Multiple missions to the moon in the past five years have revealed our nearest celestial neighbor is a fascinating place,” said NLSI director Yvonne Pendleton, who spoke at the event “The Apollo-era views, rich in geological insights from samples that continue to be studied today, have been enlarged to reveal detailed topography, composition and a bombardment history that will fascinate researchers for many years to come.”

More than 2,000 people viewed the eclipse at the event. Safe viewing equipment was also sent to other national parks and another public viewing was held by one of the NLSI teams at the University of Colorado football stadium in Boulder, where 10,000 people viewed the partial eclipse.

“Nature has provided us with a unique opportunity to capitalize on the huge public interest in the sun and moon,” said NLSI Director of Education and Public Outreach Brian Day. “It is an excellent opportunity to engage with the public and explain what we are doing at Ames.”

Although there have been a number of partial eclipses in recent years, May 20, 2012 was the first time in 18 years that we have been able to see the moon pass directly across the center of the sun from the U.S. James Schalkwyk
Ames Research Center, Moffett Field, Calif.

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Posted by on June 12, 2012 in Earth Changes, NASA, Science, Space

 

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Large X-class Flare Erupts on the Sun

Good thing it wasn’t aimed at Us! If it was we’d be gone, gone, gone! Just image a blast of plasma hitting earth at temperatures greater than 100,000 degrees!

On Jan. 27, 2012, a large X-class flare erupted from an active region near the solar west limb. X-class flares are the most powerful of all solar events. Seen here is an image of the flare captured by the X-ray telescope on Hinode. This image shows an emission from plasma heated to greater than eight million degrees during the energy release process of the flare.

Image Credit: JAXA/Hinode

 
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Posted by on February 7, 2012 in Earth Changes, Global Warming, NASA, Photo, Science, Space

 

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Darkness No More

How strange I felt looking upon this nighttime photo and seeing just how bright our city lights are. It is no wonder that we cannot see the beauty of the night anymore. It is something I love about living in the country, to just look up and see an infinite amount of stars and just wonder what it would be like to visit those distant places and make friends with those other life-forms. Gotta be optimistic here as I wouldn’t want to visit a distant worlds and become a mid-day snack.But I was also struck at the rare glimpse of earth with a darkened horizon, most photos always show us as a blue orb and we rarely see how beautifully twisted we look at night.

Western Europe at Night

With hardware from the Earth-orbiting International Space Station appearing in the near foreground, a night time European panorama reveals city lights from Belgium and the Netherlands at bottom center. the British Isles partially obscured by solar array panels at left, the North Sea at left center, and Scandinavia at right center beneath the end effector of the Space Station Remote Manipulator System or Canadarm2. This image was taken by the station crew on Jan. 22, 2012.

Image Credit: NASA

 
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Posted by on January 30, 2012 in NASA, Photo, Science, Space

 

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The Eagle Nebula

Combining almost opposite ends of the electromagnetic spectrum, this composite of the Herschel in far-infrared and XMM-Newton’s X-ray images shows how the hot young stars detected by the X-ray observations are sculpting and interacting with the surrounding ultra-cool gas and dust, which, at only a few degrees above absolute zero, is the critical material for star formation itself. Both wavelengths would be blocked by Earth’s atmosphere, so are critical to our understanding of the lifecycle of stars

Image Credit: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium

 
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Posted by on January 18, 2012 in NASA, Photo, Science, Space

 

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Merry Christmas Universe!

Hubble Serves Up a Holiday Snow Angel

The bipolar star-forming region, called Sharpless 2-106, looks like a soaring, celestial snow angel. The outstretched “wings” of the nebula record the contrasting imprint of heat and motion against the backdrop of a colder medium. Twin lobes of super-hot gas, glowing blue in this image, stretch outward from the central star. This hot gas creates the “wings” of our angel. A ring of dust and gas orbiting the star acts like a belt, cinching the expanding nebula into an “hourglass” shape.

Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

 
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Posted by on December 15, 2011 in NASA, Photo, Science, Space

 

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Warning: Black Hole Dead Ahead!

Every starship captain knows the true prime directive: steer clear of black holes. Well it appears that one object didn’t get the memo. According to a new study, a small cloud of gas and dust is racing toward the black hole at the center of the Milky Way—and when it hits, be prepared for some astronomical fireworks.

The black hole, named Sagittarius A*, weighs 4 million times as much as our sun and is 27,000 light-years away. Every star in the Milky Way revolves around it. Our sun takes 230 million years to complete an orbit, but one known star is so close that it revolves around Sagittarius A* in just 16 years.

Now astronomers have spotted a new object near the black hole. Stefan Gillessen and Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and their colleagues used the European Southern Observatory’s Very Large Telescope in Chile to observe the Milky Way’s center at infrared wavelengths, which penetrate the thick dust between it and us. The instrument picked up a small gas cloud that, over 9 years of observations, appeared to be getting closer and closer to Sagittarius A*. The astronomers detected the object at a wavelength of 3.76 microns but not at 2.16 microns. This indicates it is a cloud of gas and dust rather than a star, they say, because a star is so hot that it should be brighter at the shorter wavelength.

The cloud is about three times as massive as Earth, emits five times as much energy as the sun, and spans 250 times the distance from the Earth to the sun. Its temperature is about 550 kelvin—somewhat cooler than the surface of Venus. Sagittarius A*’s immense gravity is accelerating the cloud dramatically: in 2004, the cloud was hurtling toward the black hole at 1200 kilometers per second; by 2011, the speed had nearly doubled, reaching 2350 kilometers per second. At that velocity, an airplane could circle the Earth in 17 seconds.

The cloud will approach Sagittarius A* in the summer of 2013, when the center of the gas and dust will be 260 times as far from the black hole as Earth is from the sun. But as the cloud hits hot gas already orbiting the black hole, it will likely meet its end. “It became really exciting when we noticed in the 2011 data that the cloud is starting to be stretched like spaghetti,” Gillessen says. “So right in front of our eyes, we can see the black hole is destroying the cloud. The material will rain down into the black hole and release a tremendous amount of energy.” As pieces of the cloud fall into Sagittarius A* over the next decade, friction and gravity will heat them to temperatures of millions of degrees, producing x-rays , the team reports online today in Nature. Other astronomers have detected “echos” of x-rays near the galactic center—reflections of radiation that have lit up large clouds hundreds of light-years away and that likely arose when past clouds dove into the black hole and sparked outbursts of x-rays.

Astronomer Andrea Ghez of the University of California, Los Angeles, who has seen the same object in her data, wouldn’t bet her house on such drama unfolding, however. “A much more likely interpretation is that this is a star that has an infrared excess,” she says, noting that dust surrounding a star can absorb visible light and reemit it in at infrared wavelengths. If the object is merely a star, then it won’t fall into the black hole but will shoot past it as the star loops around Sagittarius A* every 140 years. Ghez says other stars with infrared excesses exist near the galactic center.

Who’s right? We’ll find out by 2013. If the object really is a gas cloud, the fireworks (at x-ray and infrared wavelengths) should reveal the extreme conditions that prevail around the galaxy’s biggest black hole — useful information not only for astronomers studying supermassive black holes in other galaxies but also for starship captains the next time they voyage to the Milky Way’s hub.

 
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Posted by on December 14, 2011 in News Article, Science, Space

 

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Space Storms to Pose Greater Risk to Flyers and Astronauts

If you thought the outlook for Earth’s climate looked bleak, don’t look up. A new study suggests that space weather—the hail of energetic particles above our atmosphere—is set to worsen in coming decades. The grim forecast suggests that astronauts and frequent flyers will face greater radiation hazards and could rule out a crewed mission to Mars before 2050.

Space weather is a general term for the environmental conditions above Earth’s atmosphere. When space weather is bad, dangerous particles abound. These include protons and ions, known as galactic cosmic rays (GRCs), raining down at near-light speed from space, and similar particles coming in bursts from the sun, called solar energetic particles (SEPs).

The sun has the biggest impact on space weather. The radiation it emits fluctuates both over the short term and across centuries. When the sun is emitting more radiation, it generates a strong external magnetic field, which swaddles the solar system in the “heliosphere”—a shield against GRCs. On the downside, a more active sun is thought to emit SEPs more consistently. Currently, the sun’s activity seems to be fading from a “grand maximum” that has been with us since the 1920s, suggesting a new minimum is upon us.

Although that might seem like good news, it’s actually not, according to space meteorologist Michael Lockwood of the University of Reading in the United Kingdom and colleagues. Lockwood’s group has analyzed how variations in GRCs and SEPs reaching Earth have correlated with the sun’s activity over hundreds of years. No one was recording the influx of GRCs or SEPs back then, so the researchers use proxy data taken from the composition of ancient ice cores dug up at the poles. Nitrates are produced as GRCs react with the atmosphere, so an ice sample containing more nitrates is likely to have been frozen at a time of abundant GRCs. Meanwhile, SEPs are thought to fill ice with rare isotopes of beryllium-10.

Lockwood’s group found that in times of low solar activity, there seem to have been more GRCs reaching Earth. This wasn’t too surprising: low activity means the solar system’s shield—the heliosphere—would have been weaker. The researchers also found that low solar activity seemed to bring fewer SEP events. But to their surprise, there was a caveat: Although fewer, the SEP events appeared to be far more intense. The worst time for SEPs appeared to be at times of “middling” solar activity—precisely the transition period we are thought to be entering. The results were published last month in Geophysical Research Letters.

How dangerous is this? One problem could arise for frequent flyers, because the thin air at high altitudes offers less protection from space weather. Currently, someone could take up to five long-haul flights every year that go near the poles—where GRCs and SEPs are channeled most—without exceeding the recommended limit on radiation exposure. But in coming decades, Lockwood explains, that safe number could drop to two. “I wouldn’t want to be on a plane when an SEP event went off,” he says.

Astronomer Sten Odenwald of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, thinks we should keep the risk in perspective. He says many people will face a greater risk of radiation from natural radon gas seeping into their basements. What’s more, Bob Rutledge, who monitors space weather at the Space Weather Prediction Center in Boulder, Colorado, adds that Lockwood and colleagues’ predictions haven’t yet been tested to see if they’ll hold up in the coming years. “Many of these theories come out, and some will prove to be right,” he says. Until time bears out a theory, Rutledge says he won’t “change the way I do business.”

Astronauts might face more problems, particularly those headed for the moon or beyond. Scientists currently predict that a roundtrip to Mars exposes a male astronaut to a lifetime’s worth of radiation; female astronauts experience double what’s considered a safe lifetime dose. But Lockwood believes that in our transition to minimum solar activity—which could last anywhere between 40 and 200 years—this dose could increase at least twofold.

Biophysicist Francis Cucinotta of NASA’s Space Radiation Program at the Lyndon B. Johnson Space Center in Houston, Texas, says it should be possible to shield astronauts against the SEP events. But GRCs would require an amount of shielding that is “not feasible” for spacecraft, he says. That means a crewed Mars mission, which NASA still has penciled in for the 2030s, would need another means of protecting astronauts.

Correction: The original version of this article attributed a quote addressing the hazard of natural radon gas to William Murtagh of the Space Weather Prediction Center in Boulder, Colorado. The article has now been corrected to attribute this quote, rightly, to Sten Odenwald of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

by Jon Cartwright

 
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Posted by on September 28, 2011 in Science, Space

 

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