Farewell Orion / See a Dragon / Aurora update

Orion's Belt (left) is reflected in calm waters in  a lake north of Duluth as the constellation tilts toward the western horizon last night. Credit: Bob King

Orion the Hunter and his three belt stars (left) are reflected in a lake north of Duluth last night. Venus, along with the Hyades and Pleiades star clusters, shine at right. Credit: Bob King

Last night while watching the northern lights, we saw the Great Hunter head for the hills. Orion has been the center of attention since December, as recognizable in the southern sky as the Big Dipper is in the north. Now he’s trotting off toward the western horizon, replaced by Jupiter, Leo and the constellations of spring.

Like a furniture clearance commercial that airs during the nightly news, ALL WINTER CONSTELLATIONS MUST GO! With new inventory coming in, the sky’s gotta make room.

Like it or not, Orion will toddle out of the picture soon. The rising and setting of the stars is a reflection of our planet’s rotation; the Earth spins toward the east, pushing up new stars from the eastern horizon and leaving those in the west behind. We see this grand parade every clear night.

View of Earth's orbit around the sun seen from above the northern hemisphere. As our planet moves to the left, the background constellations appear to drift to the right or westward. Credit: Bob King

View of Earth’s orbit around the sun seen from above the northern hemisphere. As our planet moves to the left during its yearly swing around the Sun, the background constellations appear to drift to the right or westward. Credit: Bob King

But there’s a more subtle shift happening at the same time. As Earth travels in its orbit around the sun, we peer out into different sectors of the sky at night as the weeks and months pass. Like a runner facing a different set of fan-packed bleachers while circling the track in a 1000-meter race, Earth faces Orion in winter, Leo in spring, Scorpius in summer and Pegasus in the fall.

They constellations appear to drift westward very gradually at the rate of about 1° per day. That’s small enough we don’t notice night to night. But the degrees add up. In two weeks, a constellation will drift about 14° to the west — more than the length of your fist held at arm’s length against the sky.

To see this for yourself, find a bright star like Betelgeuse in Orion or Arcturus in Bootes (located below the Big Dipper’s Handle) and note its position in relation to a nearby landmark like a church steeple, mountaintop or Pizza Hut at a particular time. Wait a few nights and then return to the exact same spot at the same time, and you’ll see that the star has slid westward.

Just the way the rising and setting of the stars is an illusion caused by Earth’s rotation, the seasonal drift of the stars and constellation is a sleight of hand caused by Earth’s revolution around the Sun. Now you know why the stars can sit still — it’s YOU who’s doing the moving.

Earth zips around the Sun at a speed of 18.5 miles per second (30 km/sec), covering 26,640 miles each day. In the time it takes for you to notice your reference star has moved – we’ll say 3 nights – you and the home planet have traveled nearly 80,000 miles!

Falcon 9 was carrying the Dragon spacecraft, which is loaded with about 4,300 pounds of supplies and payloads bound for the International Space Station (ISS). Credit: SpaceX

Falcon 9 lifts off April 14 carrying the 9,300-pound Dragon spacecraft, which was loaded with about 4,300 pounds of supplies and payloads for the International Space Station (ISS). Credit: SpaceX

Being outside at night can be a wonderful thing because you inevitably see something unexpected. Two nights ago, I was out with my astro class and we saw the weirdest pair of satellites in the northeastern sky – a bright one and a faint companion just a few degrees apart. Both moved quickly and faded out in less than a minute.

I later discovered we saw the Dragon cargo ship en route to deliver supplies to the International Space Station and the upper stage of the Falcon 9 rocket that lofted the ship into orbit.

You can see either or both in the next few nights by going to Heavens Above and selecting your city and then clicking on the Dragon CRS-6 link just below the ISS link under the Satellites heading. Passes are only a minute or two long and occur in evening twilight. The brighter object will be the rocket stage.

The Falcon rocket's second stage engine burns for about 7 minutes to deliver the Dragon ship to its initial orbit. Credit: SpaceX

The Falcon rocket’s second stage engine burns for about 7 minutes to deliver the Dragon ship to its initial orbit. Credit: SpaceX

Bring binoculars and you might still be able to see the solar panel covers that were ejected from the Dragon as separate fainter objects nearby. Dragon will arrive at the space station around 6 a.m. CDT tomorrow (April 17), when astronauts will use the robotic arm to secure it. I expect that tonight, Dragon will follow the ISS by only a couple minutes.

Last night’s aurora glowed until the wee hours. I hope you were able to see at least some of the show. Tonight, forecasters predict another chance for more northern lights though they’re expected to be a little “quieter” than yesterday.

Fall color by satellite

NASA’s Terra satellite captured this view of fall color around the Great Lakes on September 26, 2014. The colors are especially impressive across Michigan’s Upper Peninsula and southern Ontario, Canada. Click to enlarge. Credit: NASA

I thought the fall colors were spectacular in northern Minnesota this week until I saw the view from 440 miles up taken by NASA’s Earth observation Terra satellite. Michigan’s Upper Peninsula is on fire with reds, oranges and yellows.

Seth Piekarski of Northfield, Minn. carefully frames his photo of Oberg Lake taken from the Oberg Mountain overlook up along the north shore of Lake Superior Friday afternoon. Credit: Bob King

Not to complain. Everything’s gorgeous right now. The decline in sunshine and heat causes the chlorophyll in the leaves to break down. Hidden beneath the gaudy green awaiting their turn in the sunshine are other colorful compounds – yellow and orange carotenes and xanthophyll pigments and red anthrocyanin. Carotenes are the same compounds that give bananas, carrots, buttercups and daffodils their color. Anthrocyanins color cherries, strawberries and red apples

Terra view of the Eastern Seaboard along with parts of Ontario and Quebec photographed on September 27, 2014. Click to enlarge. Credit: NASA

These compounds don’t decay as fast as chlorophyll, so they shine through in yellows, oranges, and reds as the green fades. The anthrocyanins, which give leaves the rich purples and reds that delight the eye, are affected more by fall weather. If the temperature stays above freezing, more anthrocyanins can form. Dry weather increases sugar concentration in trees’ sap, which increases the production of yet more anthrocyanin. That’s why the best fall colors happen when it’s dry and sunny and not too cold at night.

Happy leaf kicking!

Oh, the humanity! Revel in NASA’s ‘Global Selfie’

A low-resolution preview of the 3.2-billion-pixel sized NASA Earth Day Global Selfie 2014 photo mosaic. The image is comprised of 36,422 individual photos submitted by people around the world. Click to go to the large, interactive gigapan image. Credit: NASA/JPL-Caltech/NOAA

Last month on Earth Day NASA asked anyone with a camera to snap a selfie to create a portrait of the planet made of thousands of individual faces – a ‘global selfie’. The project was designed to encourage environmental awareness and recognize the agency’s ongoing work to study and protect our blue world through satellites (17 in all), airborne and ground-based monitoring.

A tiny sample of NASA’s ‘Global Selfie’. Credit: NASA

People on every continent – 113 countries and regions in all – posted pictures. After weeks of curating more than 50,000 submissions from Twitter, Facebook, Instagram, Google+ and Flickr, a grand portrait using 36,422 individual photos was finally assembled into a gigantic mosaic.

A great example of photos taken by the Suomi NPP satellite is this composite image of Earth at night taken during April and October 2012. It took 312 orbits and 2.5 terabytes of data to get a clear shot of every parcel of Earth’s land surface and islands. Click for a monsterly awesome version. Credit: Robert Simmon

The background photos of the Earth itself are based on pictures of each hemisphere captured on Earth Day 2014 by the Suomi National Polar-orbiting Partnership (NPP) satellite. Suomi NPP, a joint mission between NASA and the National Oceanic and Atmospheric Administration, collects data on both long-term climate change and short-term weather conditions.

To really dig in, explore the full-resolution gigapan image. You can zoom and scroll across all 36,422 photos. Clicking on the ‘Snapshot’ icon in the lower left of your screen highlights one row of images at a time with information about each picture with the glide of your mouse. Unfortunately there’s no search engine to find individual photos by name. I’m still searching for mine!

Cosmos 1220 spy satellite safely burns up in atmosphere

Amateur video of Cosmos 1220 burning up over Saudi Arabia during re-entry Sunday

The Russian military reconnaissance satellite launched in 1980 and designed to spy on enemy naval forces met a fiery end Sunday morning when it re-entered Earth’s atmosphere around 8 a.m. CST. This according to Russian defence ministry spokesman Colonel Dmitry Zenin.

Because Cosmos 1220 was an older satellite with no protocols set up to pilot it to a safe fall over an ocean, there was some concern that any debris surviving re-entry might crash down over inhabited lands. While I haven’t heard exactly where it came down and whether any pieces have been found, there have been no reports of injuries out of Saudi Arabia or anywhere else connected to machines falling out of the sky.

The most recent large satellite to de-orbit and burn up was the European Gravity Ocean Circulation Explorer (GOCE) on November 10, 2013. It disintegrated in the South Atlantic Ocean near the Falkland Islands.

A satellite falling on your head is a scary thought until you consider the broader context. Heiner Klinkrad, head of the ESA’s Space Debris Office at the time of GOCE’s descent put it this way: “In the 56 years of spaceflight, some 15,000 tonnes of man-made space objects have re-entered the atmosphere without causing a single human injury to date.”

New view of U.S. at night – Could someone please dim the lights?

The U.S. on the night of Oct. 1, 2013 photographed by the Suomi-NPP satellite from 512 miles high. Light clouds cover the region from Minneapolis across northern Wisconsin. Click for a supersized version you can dig into and find your city. Credit:  Jesse Allen and Robert Simmon

On Oct. 1 this year – a rare, almost cloud-free night across the continental United States – NASA snapped a series of natural light photos of the country with the Suomi-NPP satellite. The satellite orbits 512 miles (824 km) high in a polar orbit and is named for the late Verner Suomi, a pioneer in satellite meteorology.

Suomi-NPP satellite views showing Earth at night – narrated

Unlike many communications satellites, which orbit around Earth’s equator, Suomi-NPP circles the planet from pole to pole. As Earth rotates beneath it, the satellite sees a different slice of the planet each orbit. Over time, all the slices add up to give Suomi a complete picture of the Earth below.

Click image to go to a scroll-able map comparing U.S. highways with their night appearance.

That night, not only was it mostly clear across the U.S. but the moon was three days before new. The little bit of light it cast was not enough to illuminated the ground or atmosphere, allowing for good contrast between lights and landscape.

The rapid growth of lighting in the Bakken oil fields in western North Dakota shows up clearly in this cropped version of the photo above. Credit: Jesse Allen and Robert Simmon

Cities large and small stand out while highways festoon the darkness like strings of holiday lights. I’m always intrigued by the latest images of Earth at night because they let us gauge how bright our planet is becoming. One of the most appalling examples of recent light pollution comes from oil drilling and exploration in the Bakken formation in western North Dakota. A dozen years ago it was one of the darkest places on the planet. Now lights spread across more than a 100 miles (160 km) of high prairie.

You may have noticed a change in lighting type in your own city. Most roads and byways are illuminated by pink-orange high pressure sodium lights. They work well when boxed in shielded housings that focus the light downward onto the streets where it’s needed. Unfortunately, many sodium lights are unshielded, sending light sideways and upward. Light in those directions not only creates unwanted glare but seriously brightens the night sky, robbing many of the joy of stargazing.

Comparison of lighting colors and intensity of the new LED streetlights (left) and the older high-pressure sodium vapor lamps. Both these lamps are shielded – the photos were taken from very similar angles to show the difference in intensity. Credit: Bob King

Recently, much more energy-efficient LED (light-emitting diode) lights are now being packaged in ornamental as well as standard streetlighting. I’ve seen the change in my own city of Duluth, Minn. While these lights have tremendous energy benefits, they are INTENSELY bright, much more so than the “old-fashioned” sodiums.

As long as they’re shielded, light spill and glare are relatively well-controlled (though light reflected off snow becomes a bigger problem), but I’m concerned that low-cost LEDs will proliferate in ornamental and building and parking lot illumination. Much of that lighting is unshielded and heavy on glare, making driving at night more difficult and preserving what dark sky is left more challenging.

I encourage you to learn all you can about the new lighting and work with you local city councils and town boards to explain how LED lighting can be used wisely to make everyone happy – stargazers, drivers and those who walk at night. For help and more information, drop by the International Dark-Sky Association website.

Falkland Island resident captures photo of GOCE satellite burning up

Nighttime photo of the Falkland Islands and southern South America taken by the Suomi NPP satellite. The lights in the Atlantic are from fishing boats. The GOCE satellite crashed into the ocean Sunday evening. Credit: NASA

The one-ton GOCE satellite burned up in the atmosphere over the Falkland Islands yesterday in the South Atlantic Ocean some 300 miles east of Argentina. Resident Bill Chater saw it happen and tweeted: “We saw it burn up from the Falklands at about 9.20 pm last night. Came from the South breaking up into bits. ”

“Driving southwards at dusk, it appeared with bright smoke trail and split in 2 before splitting again into more and going on north,” he added. While I’m still waiting on permission to run his photo that doesn’t mean you can’t see it right now.

Scientists at the European Space Agency are studying the photo and everything seems to check out as far as place, time and appearance. The picture shows a long thin contrail with an elongated bright cloud at its center. Any parts and pieces that survived re-entry will only be seen by those who swim in deep waters for a living.

GOCE satellite expected to crash-land who knows where today

GOCE (pronounced GO-chay) is 17 feet long and dubbed the “Ferrari of Space” because of its sleek design. It will burn up later today in Earth’s atmosphere. Credit: ESA

Get out the way! The European GOCE (Gravity field and steady-state Ocean Circulation Explorer) satellite ran out of fuel in October and it’s on the way down. Scientists at European Space Debris Office expect it to plunge through the atmosphere between 12:30 p.m. and 6 p.m. this afternoon.

The position of GOCE is tracked by GPS satellites – slight shifts in its orbit from the continuously changing gravitational pull of land and water below are used to obtain gravity field information. Credit: ESA

Since most of the Earth’s surface is ocean, that’s where GOCE’s likely to fall … but you never know. This isn’t a controlled re-entry, so there’s a small chance it could land in your backyard. A very small chance. If it does burn up over inhabited land it will be a spectacular sight even in the daytime.

Most of the 2,000-pound satellite will burn up harmlessly, but Heiner Klinkrad, head of the Space Debris Office, estimates that about 20 percent or 440 pounds (220 kg) of debris in the form of dozens of fragments will survive the plunge and reach the ground along a sizable re-entry swath.

Spread out this way, the chances of a particular piece of machinery coming down on your head is exceedingly small. But if that does happen, you’ve got options. According to a 1972 U.N. agreement called the Convention on International Liability for Damage Caused by Space Objects, you’re fully covered by the European Space Agency in case of damage to life or property.

A picture of Earth’s gravity field – the most detailed ever – from the GOCE satellite. The colors in the image represent deviations in height from -100 meters to +100 meters (-328 feet to +328 feet) from an ideal shape. Blue represents low and red/yellow high. Africa is at right and South American at left. Credit: ESA/HPF/DLR

GOCE’s currently about 90 miles up and losing 0.6 miles of altitude for every orbit it makes from friction with the atmosphere. It was launched in March 2009 on a mission to precisely map Earth’s gravity field and ocean currents and create a high-resolution map of the boundary between Earth’s crust and mantle (dense rock layer directly beneath the crust that’s some 1,800 miles thick.)

Primer on GOCE’s mission

One of the coolest things it did was create a detailed map of the “geoid” or virtual map showing the strength of gravity across the planet. Mountain ranges, composed of dense rock, have a stronger gravitational pull on the spacecraft compared to ocean waters. Every minute variation in gravity altered GOCE’s orbit a little bit here and a little bit there. Combined with data from its internal gravity-measuring gradiometers, the probe compiled the information to create a map showing a very lumpy Earth.

Frame from the live tracking widget grabbed at 10:30 a.m. when GOCE was over the Indian Ocean headed toward Antarctica. Credit: ESA

Mapping the geoid helps scientists better understand sea level changes and global ocean circulation which are in turn affected by climate change.

I’ll report back later today when GOCE bites the dust. In the meantime click HERE to track it live from your phone or computer.

Please note that it sometimes takes a minute for GOCE to show up on the tracking map.

** UPDATE 8:15 p.m. CST: According to the BBC News, GOCE has re-entered Earth’s atmosphere. It was last sighted at 4:52 p.m. CST passing just 75 miles (121 km) over Antarctica. Any debris that survived the fiery dive would have fallen anywhere from Eastern Asia across the Pacific to Antarctica. We can all breathe now!

More information can be found on Visual SAT-Flare Tracker 3D as well as on Daniel Souka’s blog. Souka is Senior Editor for Spacecraft Operations at ESOC, ESA’s European Space Operations Center in Darmstadt, Germany.

Russian BLITS satellite blitzed by Chinese space debris

Video simulations of Russian BLITS satellite orbiting Earth and then being struck by debris from the Chinese Fengyun 1C

Russia’s really getting beat up on lately. First the fireball and now one of its satellites gets whacked by a piece of Chinese space junk. In 2007 China performed an anti-satellite weapons test destroying its Fengyun 1C weather satellite leaving in its place thousands of fragments of Earth-orbiting shrapnel.

The spreading debris cloud from the Chinese anti-satellite test in 2007. Left: one month after the hit. Right: 6 months later. Credit: NASA Orbital Debris Program Office

NASA estimates the test created some 950 objects 4 inches (10 cm) or larger in a debris cloud extending from 125 to nearly 2,300 miles (200-3,850 km) high covering all of low-Earth orbit where a great many satellites – including the space station – circle the planet. At the 1/2-inch level, the garbage totals up to more than 35,000 bits and bolts.

This miasmic cloud of human hubris represents the single greatest danger to orbiting satellites since the beginning of the space age. Much of it is hundreds of miles high and will take many years to “decay” or re-enter Earth’s atmosphere.

BLITS is essentially two spheres (one nested in the other) that measures a mere 6.7 inches in diameter. Half of the outer ball has a reflective coatings. Laser light beamed to the satellite returns to Earth. Timing the pulse gives a precise distance to the satellite. Credit: IPIE

The Russian Ball Lens in The Space (BLITS) nanosatellite, a small 16-lb. satellite used for laser-ranging studies, had been functioning properly when on January 22, 2013 it was hit by Chinese satellite debris according to an analysis by the Colorado-based Center for Space Standards and Innovation. Scientists noticed a sudden change in its orbit, spin period (amount of time it take to turn around its axis) and orientation in space. By Feb. 28 they knew the culprit: a chunk of Fengyun 1C debris.

Satellites need to rotate at a precise rate and orientation to maintain contact with Earth as well as serve as useful platforms for experiments. BLITS, now shattered into at least two pieces, tumbles about like a leaf. The satellite was equipped with mirrors called retroreflectors that reflected back brief pulses of laser light shot from an Earth station. By precisely measuring the time for light takes to make the two-way trip, scientists can determine the satellite’s distance to millimeter accuracy.

Frame grab from the video showing the impact of Fengyun 1C debris on a collision course with Russia’s BLITS satellite.

With that data, they’re able to measure Earth’s gravity field and seasonal height variations of the atmosphere, map the surface of the oceans and even tap into the structure of Earth’s interior.

Pity it was likely destroyed. We can only hope this serves as a lesson to other nations who might contemplate similar anti-satellite tests. Littering is bad whether on Earth or in orbit. Read more about the collision HERE.

The night the Cosmos fell to Earth

One of Russia’s Cosmos satellites (there are many in a series). Cosmos 1484 gathered data on natural resources from orbit.

Last night around 9:30 p.m. Eastern time, hundreds of residents living along the East Coast of the U.S. were treated to a spectacular, slow-moving, long-lived meteor about as bright as the full moon. But there was something different about this meteor – it was man-made.

To get a feeling for what most of us missed, check out the American Meteor Society’s fireball reporting site. As of this afternoon, over 30 reports from 8 different states have been received that correlate with the time and path of the Russian Cosmos 1484 reconnaissance satellite which was expected to re-enter the atmosphere around that time. The U.S. Strategic Command reported the re-entry or “decay” (in satellite lingo) at 9:38 p.m. EST +/- 17 minutes.

Short video of Cosmos 1484 crossing in front of the moon taken by an amateur astronomer

Cosmos 1484 was launched from Russia’s Baikonur cosmodrome in 1983, the same place Yuri Gagarin, the first human to orbit the Earth, lifted off on April 12, 1961. The Cosmos probe was classified as a “remote sensing” satellite, another way of saying it studied its subject without touching it – from orbit. Using cameras, radar and other sensors, Cosmos gathered information on natural resources like forests, cropland, lakes and seas for use by the-then Soviet Union in planning its economy.

When the sample capsule from the Japanese Hayabusa spacecraft entered Earth’s atmosphere in June 13, 2010, it created a spectacular fireball. The capsule, containing particles from the asteroid Itokawa, landed safely. Click for awesome video. Credit: Takashi-Ozaki, Yomiuri Simbun, AP

Over time, the orbit of 5,500-lb. Cosmos 1484 “decayed” due to the inevitable drag of air molecules. While there aren’t many of them at typical low Earth-orbit altitudes, their effect accumulates and accelerates over time.

Even at 250 miles high, the International Space Station needs to periodically fire its engines to boost its altitude from time to time. Some newer satellites have rockets and controls to counter atmospheric drag and maintain a preferred orbit. Many others, especially the older ones like Cosmos 1484, either don’t or have run out of fuel.

Air drag lowers a satellite’s orbit, which causes it to speed up, which further increases drag, which speeds it up even more in an ever-spiraling process until the satellite finally re-enters the atmosphere in a ball of fire. Satellite re-entry speeds are normally much slower than the cosmic speed of meteors – those bits of asteroid and comet dust – so they take their time crossing the sky as they put on a fiery show.

One of Skylab’s air tanks that made it through re-entry and crashed to the ground. It’s on display at US Space and Rocket Center, Huntsville, Alabama. Credit: Wikipedia

A falling satellite – that’s what you lucky East Coasters saw last night. I’ve only heard of one report of fragments picked up by Doppler weather radar possibly in Georgia. Most satellites completely burn up upon re-entry, but sometimes pieces survive. One notable example was the plunge of NASA’s Skylab Space Station when it re-entered over Australia near Perth on July 11, 1979. After a mouth-dropping show of satellite-frying fireworks, at least two dozen pieces were picked up.

If you’re interested in what satellites will be dropping back to Earth in the near-future, click over to Satview’s Reentry site.

Earth at night glows with lovely and loathsome lights

This image of the continental United States at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. City and highway lights, gas flares, wildfires and a bit of reflected moonlight are visible. Click for a huge version. Credit: NASA Earth Observatory/NOAA NGDC

Wherever we go, our lights go with us. If we were more thoughtful about choosing the right type of lighting fixtures, it wouldn’t be such a problem, but we’re generally not. Photos taken late last year by the Suomi NPP satellite of Earth at night show the human footprint in blazing garlands of twinkling orange lights strung along coastlines, cities and highways.

While the sight is beautiful on one level, it’s a disturbing waste of good energy. Much of the electric lighting seen from space spills upward to brighten the night sky instead of being directed at the ground where it’s needed.

Comparison photos of the Bakken oil fields region in the year 2000 before active drilling and in 2012 with drilling going full bore. The photo at left was made by the Defense Meteorological Satellite Program; at right by Suomi NPP. Click to enlarge. Credit: NOAA, NASA

One of the most glaring examples of new light pollution shows up in the Bakken shale fields of northwestern North Dakota. Although one of the least densely-populated areas of the United States, the region has seen widespread oil-drilling and natural gas production in recent years. Most of the bright dots are lights associated with drilling equipment and temporary housing near drilling sites, but some are natural gas flares.

Closeup satellite image of lighting in the Bakken oil fields of northwestern North Dakota. Credit: NASA Earth Observatory/NOAA NGDC

Storage facilities and pipelines haven’t kept up with production, so the excess is burnt off in flares. This may sound like a bad idea, but it’s better than releasing it directly into the atmosphere. Methane is far nastier than carbon dioxide when it comes to the greenhouse effect.

Well-designed fixtures shield and direct light toward the ground. This example is from Manchester, UK.

While we all know lighting is necessary to carry on with tasks at night like driving home or picking up the kids at school, wisely-designed fixtures that contain the light in a box and direct it downward not only provide ample illumination, they also save energy, reduce glare and minimize light pollution of the night sky we all love.

Full moon on September 30, 2012 over the Persion Gulf. You can see both the lights of cities and highways as well as details of the landscape. Click to enlarge. Credit: NASA Earth Observatory/NOAA NGDC

Not all Earth lighting seen from orbit is manmade. Moonlight and aurora cast their natural hues across the planet’s skin, too. The Suomi NPP satellite captured a series of pictures showing dramatic changes in illumination of the Persian Gulf region between September 30 and October 15, 2012 when the moon waned from full to new phase.

With the moon at gibbous phase, the difference in lighting is quickly apparent. Click to enlarge. Credit: NASA Earth Observatory/NOAA NGDC

Notice that as the moon’s phase lessens, the cities become more obvious while the landscape darkens. To see all four panels showing the complete transition from full to new moon, click HERE.

The southern lights swirl over Antarctica in this satellite image taken on July 15, 2012. Look closely and you’ll see details in the ice shelf along the edge of ocean (top) lit up by the aurora. Credit: NASA Earth Observatory image by Jesse Allen and Robert Simmon

We’ll leave you with the choicest image of all – the aurora austrinus or southern lights, counterpart to the aurora borealis. Suomi NPP captured this image on July 15, 2012 over Antarctica’s Queen Maud Land and the Princess Ragnhild Coast. At the time the continent was shrouded in mid-winter darkness with a waning crescent moon providing very little illumination. LIght from the aurora was bright enough however to reveal icebergs and the coastline.

If you like your skies dark, here are some outdoor lighting tips on reducing light pollution around the house. For more on the issue, I highly recommend a visit to the International Dark-Sky Association’s Frequently Asked Questions.