Space and astronomy news
Noctilucent clouds are one of the atmosphere’s most ethereal natural wonders. They form high in the mesosphere, about 80 km (50 mi) above the Earth’s surface, and are rarely seen. In July, 2018, NASA launched a five-day balloon mission, called PMC (Polar Mesospheric Clouds) Turbo, to observe them and photograph them.
Continue reading “Noctilucent Clouds Perform Delicate Dance for NASA’s Balloon-Cam”
This year, the noctilucent cloud season has been especially eventful, and this new timelapse from Swedish astrophotographer Göran Strand shows these “night-shining” clouds covering the entire sky over the course of 2 hours.
“On the 27th of July 2014 I saw some of the most beautiful Noctilucent Clouds I’ve ever seen,” Göran said via email. “They emerged shortly after sunset and after a while they covered the entire sky.”
In the movie you can see an all-sky timelapse view that shows how these clouds changed during the evening.
See some gorgeous still photos from that night, below:
Noctilucent clouds are wispy, glowing tendrils of high-altitude ice crystals that shine long after the Sun has set. They appear in upper latitudes only and form about 83 km (51 miles) up in the atmosphere. The icy clouds are illuminated by the Sun when it is just below the horizon, giving the clouds their “night-shining” properties.
Also called polar mesospheric clouds, these are the highest cloud formations in the atmosphere. They’ve been associated with rocket launches and space shuttle re-entries, and another theory is that they might also be associated with meteor activity.
See more of Goran’s work at his website, or follow him on Twitter and Facebook.
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A trio of talented Dutch astrophotographers have captured a series of magnificent views of the rare and beautiful phenomena known as Noctilucent Clouds, or NLCs, during a spectacular outburst on the night of July 3, 2014 in the dark skies over southern Holland – coincidentally coinciding with the fireworks displays of the Dutch 2014 FIFA World Cup team and America’s 4th of July Independence Day celebrations!
“I suddenly saw them above my city on the night of July 3rd and ran for my camera!” said Dutch astrophotographer Rob van Mackelenbergh, who lives in the city of Rosmalen and excitedly emailed me his photos – see above and below.
“I was lucky to see them because I left work early.”
Noctilucent clouds are rather mysterious and often described as “alien looking” with “electric-blue ripples and pale tendrils reaching across the night sky resembling something from another world,” according to a NASA description.
They are Earth’s highest clouds, forming on tiny crystals of water ice and dust particles high in the mesosphere near the edge of space by a process known as nucleation, at altitudes of about 76 to 85 kilometers (47 to 53 miles).
NLCs are generally only visible on rare occasions in the late spring to summer months in the hours after sunset and at high latitudes – 50° to 70° north and south of the equator.
Another pair of Dutch guys, Raymond Westheim and Edwin van Schijndel, quickly hit the road to find a clear view when they likewise saw the mesmerizingly colorful and richly hued outburst on July 3rd and also sent me their fabulous NLC photos.
“To have a free view to the horizon, we drove to the countryside just north of the city of Oss. On a small road we have stopped to witness these beautiful NLCs and to take pictures,” said Westheim.
See a gallery of Raymond’s and Edwin’s photos herein.
“The NLCs of last night were the most beautiful ones since 2010. They were remarkably bright and rapidly changing and could be seen drifting towards the South,” Westheim explained with glee.
“These pictures were taken a few kilometers north of our city Oss between 23:15 p.m. and 0:15 a.m. (Central Europe Time) on Thursday evening, July 3,” said Edwin van Schijndel.
Rob, Raymond and Edwin are all members of the “Sterrenwacht Halley” Observatory which was built in 1987. It houses a planetarium and a Celestron C14 Schmidt-Cassegrain telescope. The observatory is located about 50 kilometers from the border with Belgium, near Den Bosch – the capitol city of southern Holland. The well known club hosts astronomy lectures and star parties to educate the public about astronomy and science.
The spectacular NLC sky show is apparently visible across Europe. Spaceweather.com has received NLC reports “from France, Germany, Poland, the Netherlands, Scotland, Ireland, England, Estonia and Belgium.”
Here are some additional NLC Observing Tips from NASA:
NLC Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6 degrees to 16 degrees below the horizon. If you see luminous blue-white tendrils spreading across the sky, you’ve probably spotted a noctilucent cloud. Although noctilucent clouds appear most often at arctic latitudes, they have been sighted in recent years as far south as Colorado, Utah and Nebraska. NLCs are seasonal, appearing most often in late spring and summer. In the northern hemisphere, the best time to look would be between mid-May and the end of August.
The first reported sighting of NLC’s are relatively recent in 1885 by a German astronomer named T.W. Backhouse, some two years after the enormous eruption of the Krakatoa Volcano in 1883 that wreaked enormous death and destruction and which may or may not be related.
Over the past few years, astronaut crews aboard the ISS have also photographed splendid NLC imagery from low Earth orbit.
Stay tuned here for Ken’s continuing OCO-2, GPM, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more Earth & Planetary science and human spaceflight news.
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Learn more about NASA’s Mars missions and Orbital Sciences Antares ISS launch on July 11 from NASA Wallops, VA in July and more about SpaceX, Boeing and commercial space and more at Ken’s upcoming presentations.
July 10/11: “Antares/Cygnus ISS Launch from Virginia” & “Space mission updates”; Rodeway Inn, Chincoteague, VA, evening
Just in case you haven’t seen this bit of awesome yet: Noctilucent clouds and aurora showed up together in skies over Scotland on the night of August 4/5, 2013. Maciej Winiarczyk from the Caithness Astronomy Group was on hand to capture it.
Enjoy!
Intrigued by mysterious noctilucent, or night-shining clouds? This beautiful new film from TWAN (The World At Night) photographer P-M Hedén combines timelapse and real-time footage to provide a stunning compilation of his month in the field in Sweden this summer to capture these lovely blue electric clouds. Noctilucent clouds are visible sometimes low in the northern sky during morning and evening twilight, usually through late May through August, and they seem to be increasing the past few years.
Enjoy the stunning, tranquil views (lots of wildlife and night sky imagery too!) and lovely music in this new film, just published yesterday.
For more information about NLCs, Bob King wrote a great overview for us earlier this year about these “visitors from the Twilight Zone!
Recently, Italian astronaut Luca Parmitano spent a “night flight” in the Cupola of the International Space Station in hopes of capturing night-time images of his home country from space. But he saw so much more, including this incredible image of the crescent Moon rising among bright blue noctilucent clouds. These wispy and mysterious clouds appear in Earth’s mesosphere — a region extending from 30 to 53 miles (48-85 km) high in the atmosphere — at twilight, usually in early summer. They can be seen from Earth’s northern hemisphere and, obviously, are visible from space too.
You can read about Parmitano’s night flight and see more of the images he took at his Volare blog. At the close of his image-taking night flight he says, “It’s late, and tomorrow will be a long day. With those lights still filling my eyes, I slowly close the seven windows and cross the Station to return to my sleeping pod. Not even dreams could replace the beautiful reality that revolves, oblivious, beneath us.”
Find out more about the science of noctilucent clouds here in our recent article by Bob King.
Below is another image of noctilucent clouds taken by Parmitano on July 28, 2013:
Every year at this time I add a new item to my list of what to watch for in the night sky. Oddly enough, it’s clouds. I must be nuts, right? What astronomer needs more clouds? But these are different. Called noctilucent clouds (NLCs), these skittish objects are visible now and again low in the northern sky during morning and evening twilight. Late May through August is the best time to see them.
What are these wispy, sometimes eerie clouds? And how can you see them?
First a caveat. If you live in Mississippi your chances of spotting them are slimmer than a string bean. Uncommon to begin with, NLCs are typically visible at higher latitudes; the northern U.S., Canada and Europe are prime outposts for an NLC vigil.
NLCs hole up in Earth’s mesosphere, a rarefied blanket of air extending from 30 to 53 miles (48-85 km) high. Most of the meteors we see burn up in this layer. It’s also extremely cold up there with temperatures at the top dropping to a teeth-rattling -130 F (-90 C). Because of their great height, noctilucent clouds reflect sunlight long after sunset when other clouds have gone gray and colorless. Their color is imparted by the ozone layer located 12-19 miles (19-30 km) overhead. The reds and oranges of reflected sunlight are absorbed by ozone on their way down to our eyes, tinting the clouds blue.
For any cloud to take shape and grow, water needs to stick to something. In day-to-day clouds, dust from wind storms – especially from the world’s deserts – supplies the necessary “nuclei” for the formation of water droplets and ice crystals.
Cirrus clouds, the ones that look like feathers wafting across the daytime sky, are typically about 10 miles high. Composed of ice crystals, they float near the top of the lowest, thickest layer of air called the troposphere. Noctilucent clouds share the realm of the Greek gods, basking in sunlight well into the night at an altitude of some 50 miles. That’s nearly as high as the aurora borealis, which can shimmy down to a scant 60 miles.
Since it’s next to impossible to get dust up high enough to provide nuclei for noctilucent cloud formation, scientists suspect outer space dust from meteoroids and comets provide some of the necessary material. As Earth travels around the sun, it sweeps up some 40,000 tons of interplanetary dust a year, plenty to get the job done. Other sources include volcanic dust and even chemical residues from rocket exhaust from the once-frequent launches of the space shuttle.
Winds from summer storms carry the water vapor into the mesosphere from the lower atmosphere which condenses on terrestrial and extraterrestrial dust nuclei. That’s why NLC displays are most frequent in summer.
Here in Duluth, Minn. at 47 degrees north I’ve seen probably half a dozen displays in years of sky watching, but to be honest, I only started looking for them in a dedicated way in the last 5 years. As late May approaches and twilight stretches deep into the evening hours, I scan the sky hoping for their return. The key to spotting NLCs is to find a place with a wide-open view of the northern horizon.
In the north, the sun retires around 9 p.m. and twilight ends more than two hours later. Watch for NLCs starting about an hour after sunset when cirrus clouds have turned pale gray and the stars begin to come out. From my home, they typically hover between 5 and 10 degrees (about a fist held at arm’s length or less) high above the northern horizon. The clouds make their first appearance at the upper end of that range, but as dusk deepens, they shrink back toward the horizon.
Video of NLCs from the Science Photo Library
NLCs look WEIRD. It’s not only their telltale eerie, plasma-blue coloration but their form that gives them away. Stripes, undulations, curls, streaks are mixed together in a way that seems alien. You might expect these on Mars maybe, but Earth? Binoculars are a huge help in appreciating the clouds’ peculiar textures and color. I say this because I’ve forgotten mine on several occasions. Two other dead giveaways – NLCs will grow brighter for a time as the sky grows darker. Regular clouds behave the opposite. NLCs also move and change shape very slowly because they’re so high up and far away.
Night-shining clouds remain aglow until nearly twilight’s end. The cut-off viewing time for the northern U.S. is about 2 hours after sunset or earlier if the mosquitos have their way. By then the sun drops too far below the horizon to provide the light to sustain them. Those living farther north in Canada, northern Ireland, England and Finland, where the sky is never truly dark during the early summer months, can enjoy NLC viewing all night.
There are indications that NLC displays are becoming more common, even pushing into lower latitudes in the past 20-30 years. It might have to do with increased levels of carbon dioxide in Earth’s atmosphere. While CO2 helps to warm the lower air layers, it can can cause the upper atmosphere to grow chillier, creating the cold conditions necessary for accelerated noctilucent cloud formation. You can dig deeper into the topic HERE.
For more about Earth’s most unusual clouds, stop by the Noctilucent Cloud Observers’ Homepage. Like the northern lights, a thrilling noctilucent cloud display is a quest worth a trip to the north country.
Mysterious “night shining” or noctilucent clouds are beautiful to behold, and this stunning image offers an unusual view of these clouds as seen by astronauts on board the International Space Station. Also called polar mesospheric clouds, these clouds are puzzling scientists with their recent dramatic changes. They used to be considered rare, but now the clouds are growing brighter, are seen more frequently, are visible at lower and lower latitudes than ever before, and sometimes they are even appearing during the day.
The astronauts were also able to take a time-lapse sequence of these clouds on June 5, 2012, as seen below. According to NASA, it is first such sequence of images of the phenomena taken from orbit.
The sequence in this video was taken while the ISS was passing over western Asia. By focusing on the limb of the Earth at night with the Sun illuminating it, the crew was able to capture some movement to these mysterious clouds.
There is quite a bit of debate for the cause of noctilucent clouds. Dust from meteors, global warming, and rocket exhaust have all been tagged as contributors, but the latest research suggests that changes in atmospheric gas composition or temperature has caused the clouds to become brighter over time.
Noctilucent clouds are usually seen during the summertime, appearing at sunset. They are thin, wavy ice clouds that form at very high altitudes (between 76 to 85 kilometers (47 to 53 miles) above Earth’s surface and reflect sunlight long after the Sun has dropped below the horizon. They appear in both the Northern and Southern Hemisphere and appear as delicate, shining wispy clouds against the dark sky.
The top image from the ISS was taken on June 13, 2012, as the space station passed over the Tibetan Plateau. At the same time, polar mesospheric clouds were also visible to aircraft flying over Canada. In addition to the noctilucent/polar mesospheric clouds trending across the center of the image, lower layers of the atmosphere are also illuminated. The lowest layer of the atmosphere visible in this image—the stratosphere—is indicated by dim orange and red tones near the horizon.
Lead image caption: Noctilucent or Polar Mesospheric clouds captured by the crew of the ISS on June 13, 2012. Credit: NASA
Source: NASA Earth Observatory
It’s Noctilucent Cloud season! And Brendan Alexander in Donegal Ireland captured this beautiful view on the morning of June 18, 2012. “The skies cleared before dawn and I was treated to the best Noctilucent Cloud display I have seen this season so far,” Brendan said on Flickr. We’ve featured Brendan’s work many times on Universe Today.
Details:
Location: Killygordon, Lifford, Co. Donegal, Ireland
Date: 18 June 2012
Time: 02:00-02:30
Camera: Self modded Canon 1000D, Simga 20mm
Exposure: 6sec, ISO 400 F5
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
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Astronomers usually curse and shake their fist at clouds for obscuring the sky and spoiling their observations. This month however, we enter the season when, after dark, thin veils of clouds appear to glow with an eerie blue light and are eagerly awaited and sought after.
Polar mesospheric, noctilucent or night shining clouds (NLC) form at the edge of space, between 76 and 85 kilometers up in the arid atmosphere, where there is one hundred millionth the amount of moisture found in the air at the Sahara Desert! Here temperatures can fall below -100 degrees Celsius, so what little water vapour is present freezes directly or forms on dust particles from micrometeors or volcanic eruptions.
During the Summer months, as the Sun stays close to the horizon, its rays illuminate these layers of ice crystals, producing a fine network of tenuous, incandescent filaments. They appear, in the Northern hemisphere, from mid May to mid August (mid November to mid February in the South) in latitudes between 50º and 70º, when the Sun is 6 to 16 degrees below the horizon. Look for them low in the Northwestern sky from an hour after sunset, or low in the Northeast before dawn.
They were first noted in 1885, two years after the eruption of Krakatoa when people were accustomed to looking at the spectacular sunsets and the glowing clouds were thought to be produced by the ash from the volcano in our atmosphere. Eventually the ash disappeared, but the clouds remained. In fact throughout the twentieth century noctilucent clouds have been occurring more frequently and across a wider area, as well as becoming brighter, perhaps due to climate change as increased greenhouse gases cool the mesosphere. The clouds also vary with the solar cycle, as ultraviolet radiation from the Sun splits the water molecules and so the clouds decrease in brightness during solar maximum. Changes in brightness seem to follow fluctuations in solar radiation but about a year later, though nobody knows the reason for this time delay.
The clouds have been found to be highly reflective to radar, possibly due to sodium and iron atoms, stripped from micrometeors, forming a thin metal coating on the ice grains. In 2006 Mars Express discovered similar clouds, forming from carbon dioxide 100 kilometers up in the Martian atmosphere, that were also only observed when the Sun was below the horizon. In 2009 the Charged Aerosol Release Experiment (CARE) created artificial noctilucent clouds using rocket exhaust that were observed for several weeks. In July 2008 the crew aboard the ISS were treated to a noctilucent cloud display over Mongolia and were able to capture the image above.
So over the Summer months, keep an eye on the northern horizon after dark for a chance to catch these beautiful and unusually welcome clouds.
Find out more at NLC