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Wednesday, March 18, 2015

Aurora borealis: NASA astronaut Terry Virts captures northern lights from International Space Station

NASA Goddard Space Flight Center Following Aurora over North America Using the “day-night band” (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS), the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite acquired this view of the aurora borealis on March 18, 2015. The northern lights stretch across Canada’s Quebec, Ontario, Manitoba, Nunavut, and Newfoundland provinces in the image, and are part of the auroral oval that expanded to middle latitudes because of a geomagnetic storm on March 17, 2015. The DNB sensor detects dim light signals such as auroras, airglow, gas flares, city lights, and reflected moonlight. In the case of the image above, the sensor detected the visible light emissions as energetic particles rained down from Earth’s magnetosphere and into the gases of the upper atmosphere. The images are similar to those collected by the Operational Linescan System flown on U.S. Defense Meteorological Satellite Program (DMSP) satellites for the past three decades. Auroras typically occur when solar flares and coronal mass ejections—or even an active solar wind stream—disturb and distort the magnetosphere, the cocoon of space protected by Earth’s magnetic field. The collision of solar particles and pressure into our planet’s magnetosphere accelerates particles trapped in the space around Earth (such as in the radiation belts). Those particles are sent crashing down into Earth’s upper atmosphere—at altitudes of 100 to 400 kilometers (60 to 250 miles)—where they excite oxygen and nitrogen molecules and release photons of light. The results are rays, sheets, and curtains of dancing light in the sky. Read more: NASA Earth Observatory image by Jesse Allen, using VIIRS day-night band data from the Suomi National Polar-orbiting Partnership. Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense. Caption by Mike Carlowicz and Adam Voiland. Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram Dusk in the Arctic morning By Stan Honda 14 People watch a total solar eclipse from Longyearbyen, Svalbard, an archipeligo administered by Norway on March 20, 2015. (AFP PHOTO / STAN HONDA) Watching the total solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) LONGYEARBYEN, Norway, March 20, 2015 – I’ve been interested in astronomy ever since I was a kid. Late last year I left my job as an AFP news photographer to pursue a documentary project – as well as the night sky and astronomy photography that I love. I’ll shoot any kind of event like this, and I've seen partial eclipses before – but I’ve always wanted to see a total solar eclipse. A friend from the Amateur Astronomers Association of New York told me in November he planned to travel for the event to Norway's Arctic Svalbard archipelago, one of only two places with the Faroe Islands which would be experiencing “totality”. I looked at the organisers’ website and it all looked very professional, so I signed up. Sledging outside Longyearbyen, Svalbard on March 19, 2015 ( AFP PHOTO / STAN HONDA) Dog sledding outside Longyearbyen, Svalbard, on March 19, 2015 (Stan Honda) It turned out a second friend from the astronomy club was also going, along with a university professor from Arizona who they met at a previous eclipse in Kenya. We all flew to Oslo to meet the tour people, then carried on Wednesday to Longyearbyen, the “capital” of Svalbard, on board two charter planes. Day one was spent dog sledding and generally getting a feel for the place. We were staying in one of just three hotels in Longyearbyen – a tiny place ringed with mountains, with just 2,000 year-round residents, and very quiet apart from the tour buses full of eclipse chasers! An advertisement for a restaurant in Longyearbyen, Svalbard, an archipelago administered by Norway on March 19, 2015 (AFP PHOTO / STAN HONDA) An eclipse-themed restaurant menu in Longyearbyen, Svalbard, on March 19, 2015 (AFP Photo / Stan Honda) We heard of an incident that night, a tourist who was mauled by a roaming polar bear. But I must say we always felt safe in our group: there has been a guard with a rifle on every outing we made outside the town. The morning of the eclipse, I arrived at the viewing site at around 7:30 am, with a group of people wanted to go early to set up their equipment. It was -17 Celsius. But despite the cold, people were very excited. The weather was perfectly clear. People watch the partial phase of a total solar eclipse as viewed from Longyearbyen, Svalbard, an archipelago administered by Norway on March 20, 2015 (AFP PHOTO / STAN HONDA) Watching the partial phase of a total solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) At high noon here the sun is 12 degrees above the horizon, so the light in Svalbard is ALWAYS nice. But still, it was a relief to many people – including myself – to see the sun was shining, lighting up the snowy slopes around us with a pink glow. A man dressed for the cold watches with protective eyeglasses the partial phase of a total solar eclipse as viewed from Longyearbyen, Svalbard (AFP PHOTO / STAN HONDA) A man dressed for the cold watches the partial phase of the solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) Everyone was happy, and bleary-eyed. People were spread out over a large snow-covered area, about 400 of us in all. There was a large warming tent set up by the tour company, who served up coffee and tea and handed out reindeer skin blankets to keep out the cold. People watch the partial phase of a total solar eclipse from Longyearbyen, Svalbard, an archipelago administered by Norway on March 20, 2015 (AFP PHOTO / STAN HONDA) Watching the partial phase of a total solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) Some of the crowd had seen a total eclipse before, so were telling us first-timers what to expect. Even then, it was such a wild thing. 'Second contact' is seen with solar prominences (red object at top left of disk) as the sun begins to move completely behind the moon during a total solar eclipse as viewed from Longyearbyen, Svalbard (AFP PHOTO / STAN HONDA) The sun begins to move completely behind the moon during a total solar eclipse viewed from Longyearbyen, Svalbard on March 20, 2015 (AFP Photo / Stan Honda) The thing that surprised me was how dark it got. Like a deep twilight, I couldn't read my camera controls at first. When it went total, there was a big noise from the crowd and some cheering. The total part lasted over two minutes, but it actually seemed like a long time. People watch a total solar eclipse as viewed from Longyearbyen, Svalbard, an archipelago administered by Norway on March 20, 2015 ( AFP PHOTO / STAN HONDA) Watching the total solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) There was a talk yesterday to the tour group by Jay Anderson, a weather expert who has seen 25 or so total eclipses. He described in detail the different stages of the phenomenon - but mainly told people to not worry about taking photos, just to look with your eyes and experience it. A total solar eclipse as viewed from Longyearbyen, Svalbard, an archipelago administered by Norway on March 20, 2015 (AFP PHOTO / STAN HONDA) Watching the total solar eclipse in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) I like shooting photos, so I'm just used to doing that, then reliving the experience later. But for a few seconds, when it went total, I think I just looked up and thought, Wow. A really incredible experience. I had some triggering devices for my cameras so I could look up at the same time, which I did. Very surreal. People see the 'third contact' as the sun begins to appear from behind the moon during a total solar eclipse as viewed from Longyearbyen, Svalbard (AFP PHOTO / STAN HONDA) The sun begins to appear from behind the moon during a total solar eclipse viewed in Longyearbyen, Svalbard, on March 20, 2015 (AFP Photo / Stan Honda) I got some shots that I hoped for, some that came as a surprise, and I made a few mistakes. But overall I'm happy. I felt very fortunate to be here. And I hope the photos I sent allow people to share a small fraction of the experience. Right now I feel very tired, but energized. And the show is not over yet: in an hour we are off again - this time to watch the aurora borealis… Stan Honda is an independent photographer based in New York. Follow him on Instagram or visit his website. A sign warning of roaming polar bears, in Longyearbyen, Svalbard (STAN HONDA) Stan Honda, staying well clear of polar bears in Longyearbyen, on March 19, 2015 (Stan Honda) 14 This post's comments feed Add a comment Name or nickname : Email address : Website (optional) : Comment : HTML code is displayed as text and web addresses are automatically converted. Remember me on this blog ......... Eclipse thrills on remote Arctic islands, clouds mar for some Fri, Mar 20 07:43 AM EDT image 3 of 20 By Gerhard Mey TORSHAVN, Faroe Islands (Reuters) - A solar eclipse thrilled thousands of sky gazers on remote Arctic islands on Friday but clouds disappointed some viewers of a rare celestial show that was also partly visible for millions in Europe, Africa and Asia. People cheered and clapped as the moon blocked the sun for about 2.5 minutes under clear skies on the icy Norwegian islands of Svalbard, where tourists had been warned of polar bears after an attack on Thursday and risks of frostbite. But clouds masked the sky over Torshavn, the capital of the Faroe Islands further south, the only other place where the eclipse was visible from land as it swept across the Atlantic. "It was overcast, there was rain and wind. You could see nothing. It was a disappointment for everybody," said Gabor Lantos, a Hungarian tourist in Torshavn. "Some tourists were so irritated, they argued with tour operators, demanding their money back," he said, adding that would be impossible. In Svalbard, a polar bear mauled a Czech tourist on Thursday, breaking into his tent as he slept. Jakub Moravev, flown by helicopter to hospital, escaped with slight injuries to his face, chest and an arm. The Faroe Islands expected about 8,000 visitors on top of the island's 50,000 population for the first eclipse in the region in 60 years. About 2,000 people have made the trek to Svalbard, doubling the population. "I've seen aurora, I've seen some volcano eruptions, but the total eclipse is still the most spectacular thing I've ever seen. And each one is unique," said Fred Espenak, a retired NASA astrophysicist in Torshavn. In an eclipse, when skies are clear, stars and planets are suddenly visible in daytime and a ring of fire - the corona - appears around the sun. In one famous experiment, a 1919 eclipse gave evidence for Einstein's theory of relativity by showing that the sun's mass bent light from distant stars. "STRANGE LIGHT" The small audience on Friday contrasted with tens of millions of people who saw the last major eclipse in Europe in 1999. A partial eclipse was visible on Friday mainly in Europe and Russia, and it skimmed parts of north Africa, the Middle East and Asia. "It's a very strange light, really spectacular, but I expected it to be much darker, like in the evening," said Per Andersen, a Norwegian businessman who watched the eclipse in Oslo where the moon covered almost all the sun. Twitter was dominated by the eclipse, with seven of the top 10 trending terms related to the sun and moon in Germany. And the German word for "doomsday" was the ninth most popular topic. The eclipse curbed solar power production in Europe, posing a challenge to electricity grids. Germany, Europe's biggest economy, boasts the world's biggest solar powered installations, which last year supplied 6 percent of its national power needs. (With reporting by Vera Eckert in Frankfurt, Eric Auchard in Berlin, Nerijus Adomaitis and Balazs Koranyi in Oslo, Writing by Alister Doyle,; Editing by Gareth Jones) ===== Aurora borealis: NASA astronaut Terry Virts captures northern lights from International Space Station Posted 32 minutes ago Vine: Astronaut Terry Virts enjoys aurora borealis light show from ISS A bright green line sits above the world as captured from space. Photo: Terry Virts captured the northern lights from the International Space Station. (Twitter: @AstroTerry) Related Story: Aurora australis captured on social media Map: Iceland While the rest of the world looked up to the night sky, NASA astronaut Terry Virts took a glimpse outside of the International Space Station to capture the glow of this week's cosmic display. Virts, an American, witnessed the impressive light show of aurora borealis as the space station travelled above the North Pole and Russia. The northern lights, as they are also known, are the result of collisions between the Earth's gaseous particles and matter released by the Sun's atmosphere. Astronomy enthusiasts have been spoilt this week with aurora australis, or the southern lights, putting on a spectacular show in the southern hemisphere on Tuesday night. According to the Australian Bureau of Meteorology, auroras are "caused when electrically charged electrons and protons accelerate down the Earth's magnetic field lines and collide with neutral atoms in the upper atmosphere — usually about 100 kilometres above the Earth". "These collisions cause the neutral atoms to fluoresce, emitting light at many different wavelengths," BOM said on its website. Red and green are the most common shades to feature in auroras and are caused by the fluorescence of oxygen atoms, while blues and purples can appear when nitrogens atoms are at work. For those out of sight of the impressive display, all was not lost as social media lit up with photos of aurora borealis. --------- When are you most likely to see an aurora? Aurora Borealis Green is the most common colour seen in auroras. (Source: iStockphoto) Related Stories How a planet becomes a magnet, Science Online, 09 Nov 2011 Could a solar flare wipe out life on Earth?, Science Online, 23 Nov 2011 Aurora australis photos (ABC News 18/03/2015), ? What causes an aurora? And when are you most likely to see them? Auroras are produced by powerful plasma storms of highly charged particles from the Sun that slam into the Earth at 6.4 million kilometres per hour causing the planets magnetic field to vibrate like jelly. Solar storms are linked to sunspot activity, says space/radio physicist Dr David Neudegg from the Ionospheric Prediction Service. Sunspot activity generally follows an 11-year cycle. "The solar cycle goes from solar minimum, periods of low solar activity with little or no sunspots to solar maxima, periods of high activity like now," says Neudegg. About every 11 years during solar maxima the Sun's magnetic poles flip. "The solar cycle we've just gone through was the deepest solar minimum in about 60 years with very little activity and is now heading into a very modest solar maxima," says Neudegg. That solar max is thought to have peaked in mid-2014. "The number of geomagnetic storms usually peaks on the down slope of the cycle a year or two after the sunspot peaks, so while the number of sunspots is less, the individual sunspots tend to be more active so more auroras could happen." Sunspots Sunspots are cooler regions on the Sun's surface where magnetic field lines generated deep inside the Sun breakthrough the photosphere in giant loops. Because the Sun isn't solid but a superheated plasma, different latitudes on the Sun rotate at different rates causing these magnetic lines get twisted and occasionally snap like an elastic band. "When this happens a high energy solar flare is produced giving off electromagnetic radiation including x-rays," says Neudegg. Powerful flares can generate a coronal mass ejection (CME) flinging protons and other matter from the Sun into space and occasionally Earth gets in the way as the CMEs are fairly wide. Many CMEs do not affect Earth as the Sun is 150 million kilometres away and the Earths magnetic field is a small target, only 50,000 kilometres wide. "When these high energy particles hit the Earth's magnetic field, they travel down the field lines (the Earth being just a big bar magnet) towards the northern and southern magnetic poles," says Neudegg. "As they reach thicker layers of Earth's atmosphere above 90 kilometres, these charged particles collide with and excite electrons in oxygen and nitrogen atoms in the rarefied air, causing them glow as they return from an excited to a ground state. It is the process of releasing photons of light as the electrons lose energy and return the ground state which we see as the aurora." Colours of the aurora Aurora colours change depending upon which types of particles are ionised. The most common colour seen in auroras is green, which is produced by molecular oxygen at lower altitudes down to about 100 kilometres. Brownish-red hues are created by single oxygen atoms which are the most common atoms in the atmosphere above 300 kilometres. A mixture of auroral emissions from oxygen and nitrogen produces a more whitish-yellow colour. Below about 100 kilometres, molecular nitrogen glows blue if it's regaining electrons after being ionised and red if it's returning to the ground state from an excited state. These blue and red colours can put a purple edge to the bottom of an aurora at about 90 kilometres. "Viewed from space, auroras form a ring of curtains hanging down about 10 to 20 degrees of latitude arond the northern and southern magnetic poles, but can expand to lower latitudes northwards from Antarctica and southwards from the Arctic, during more powerful geomagnetic storms," says Neudegg. Dr David Neudegg is the deputy manager of the Ionospheric Prediction Service. He was interviewed by Stuart Gary. Story updated 2015 ----------------------------- Arctic eclipse alert: hotels full, it's cold, polar bears prowl Fri, Mar 13 09:19 AM EDT image By Alister Doyle OSLO (Reuters) - The Norwegian Arctic islands of Svalbard are discouraging last-minute visitors for a rare solar eclipse next week, warning that hotels are full, it will be freezing cold and polar bears are on the prowl. Christin Kristoffersen, mayor of Svalbard's main settlement Longyearbyen, told Reuters an expected 1,500 visitors for the eclipse, on top of about 2,500 residents, meant the usually welcoming archipelago had reached a maximum safe limit. "Safety comes first, even before the eclipse," she said. "We need to take care of people. It's terribly cold in March and we have the challenge with polar bears." A bear killed a British teenager on Svalbard in 2011, the most recent fatality. On average, three bears a year are shot by people in self-defense on Svalbard. A total eclipse, when the moon blocks the sun and its shadow falls on the Earth, will sweep across the Atlantic on March 20 but from land will only be visible from Svalbard and the Faroe Islands. A partial eclipse will be seen in north Africa, Europe and north Asia. In London, for instance, 84 percent of the sun will be covered by the moon. Hotels in both Svalbard and the Faroe Islands have been booked for years although the Faroe Islands still has some places to stay, including private homes. In the best of cases, with clear skies, the northern lights may also be visible during the morning eclipse. Skies on Friday are likely to be partly cloudy with a temperature of -17 degrees Celsius (1.4 Fahrenheit) in Longyearbyen and 3 Celsius (37) in Torshavn, the capital of the Faroes, the Norwegian Meteorological Institute indicates. The Faroe Islands, a self-governing nation within Denmark, expects 8,000 visitors to swell its population of about 50,000, said Torstein Christiansen, tourism and business manager of Visit Torshavn. It will be the first total eclipse on the islands since 1954, with the next expected in 2245. Faroese camping sites, which usually only open in May, will open early for hardy visitors. "And we don't have polar bears," Christiansen told Reuters. (Editing by Catherine Evans) ------------------- It's a Total Solar Eclipse in the Faroe Islands and Svalbard (Norway), and a Partial Solar Eclipse in Europe, northern and eastern Asia and northern and western Africa. The eclipse starts at 07:41 UTC and ends at 11:50 UTC. Is this Total Solar Eclipse visible in Adelaide? What the eclipse will look like near the maximum point The animation shows what the eclipse approximately looks like near the maximum point. ▶▶▶▶▶▶ ❐Partial Eclipse just started Partial Eclipse in good progress Full Eclipse starts Maximum Eclipse Full Eclipse ends Partial Eclipse continues Partial Eclipse about to end ❍↔ Where to see the eclipse Regions seeing at least a partial eclipse: Europe, North/East Asia, North/West Africa, West in North America, Atlantic, Arctic. ▶ Some cities where at least part of the total eclipse is visible Expand/collapse list of cities that can view the total eclipse ▶ Some cities where partial eclipse is visible Expand/collapse list of cities that can view the partial eclipse Area seeing the total solar eclipse. More than 90% of the sun is covered. Up to 90% of the sun is covered. Up to 40% of the sun is covered. Eclipse is not visible at all. Note: Percentage values (%) relate to moon coverage of the sun and depends on location. Visibility is weather permitting. When the eclipse happens worldwide The eclipse starts at one location and ends at another. The times below are actual times (in UTC) when the eclipse occurs. Event UTC Time Time in Adelaide* First location to see partial eclipse begin 20 Mar at 7:41 AM 20 Mar at 6:11 PM First location to see full Eclipse begin 20 Mar at 9:09 AM 20 Mar at 7:39 PM Maximum Eclipse 20 Mar at 9:45 AM 20 Mar at 8:15 PM Last location to see full Eclipse end 20 Mar at 10:22 AM 20 Mar at 8:52 PM Last location to see partial Eclipse end 20 Mar at 11:50 AM 20 Mar at 10:20 PM * Local times shown do not refer to when the eclipse can be observed from Adelaide. Instead, they indicate the times when the eclipse begins, is at its max, and ends, somewhere else on earth. The corresponding local times are useful if you want to view the eclipse via a live webcam. Eclipses visible in Adelaide. ===============

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