Dyeing To Be Noticed
It’s pretty hard not to notice a potash evaporation pond against the natural earth tones of the Utah desert, even from an altitude of 250 miles.
In the past, the production of potassium-based fertilizers has involved dangerous underground mining operations. These days the minerals are extracted from the ground via simple chemistry and solar energy.
At this site in Moab, Utah, water from the Colorado River is heated and injected into old shaft mines to dissolve the potash deposits. This solution is pumped into evaporation ponds, where the sun goes to work concentrating the solution through evaporation. An agent is added that attaches itself to the suspended potassium chloride and causes it to float to the surface, where it is skimmed off and packaged for use as plant fertilizer. A dye is added to accelerate the evaporation process, producing the somewhat shocking hue of electric blue.
Previous Image of the Week resources
January 12-19, 2018
Curtains of Unearthly Light
To mid-latitude dwellers in both the northern and southern hemispheres, the aurora may seem strange, even supernatural. A rare sight in the lower forty-eight, these dazzling displays nonetheless send a powerful message to the people of Earth by way of our northern brothers and sisters – that there’s more to our relationship with the sun than a nice afternoon at the beach. Much more.
By zooming in on the diffuse, drape-like quality of the Aurora Borealis from an altitude 250 miles above British Columbia in Western Canada, the camera challenges our sense of reality. Charged particles from the Sun interact with Earth’s atmosphere and magnetosphere to improvise a multicolored festival of light, as if to remind us that we must never take nature for granted.
Compare this shot with the ISS Image of the Week from November 11, 2017 (see archive below), a wide-angle shot that highlights the aurora’s overall circumpolar ring shape.
January 5 -12, 2018
Canal, Canali, Cannoli – Close Enough?
The late nineteenth century was all about canal building. The Suez Canal (pictured here) was completed in 1869, and reduced the travel distance between the North Atlantic and northern Indian Oceans by 4,300 miles by creating a shortcut from the Mediterranean to the Red Sea, through Egypt. The Panama Canal went online a mere eleven years later.
Telescopes were getting bigger and better at this time as well, and astronomers were spending long hours staring at neighboring planets (astrophotography wasn’t a thing yet) and mapping any discernible surface features their optics would resolve. In 1877 Italian astronomer Giovanni Schiaparelli observed a number of what he believed to be naturally occuring “canali”, an Italian word meaning “channels”, on the Martian surface. The word’s similarity to the English word “canal”, which refers specifically to an artificial waterway, led to years of bad astronomy in the person of well-to-do American astronomer Percival Lowell. Lowell devoted much of his later career to advancing his theory that the canals had been constructed by intelligent beings in order to redirect badly-needed water from the Martian poles to population centers nearer the planet’s equator.
Although most of Lowell’s contemporaries dismissed his ideas, it wasn’t until the Mars Mariner missions in the 1960s that remote sensing data could definitively prove him wrong.
December 30, 2017 - January 5, 2018
Just a few miles from Bora Bora among the Leeward Islands of French Polynesia lie Taha’a and Ra’iātea. The lush, inhabited tropical islands in the middle are remnants of eroded volcanos, while the keyhole-shaped network of turquois fringe encircling them are separate kingdoms altogether –living, evolving coral reef.
Communities of coral animals thrive in the warm, shallow waters around tropical volcanic islands. Even as the elements erode away the exposed volcanic land mass above the water, countless generations of coral go about their business building vast underwater cities of astounding biodiversity beneath the surface. Islands in tropical waters may erode away entirely, leaving behind only the surrounding reef – an atoll – to mark its former location.
Taha’a and Ra’iātea probably comprised a single, larger island before millennia of erosion split them apart.
December 16 - 29 2017
Betsiboka River Delta
Madagascar may well be the most unique place on earth. 90% of the wildlife found on Madagascar is exclusive to this small island country off of Africa’s eastern coast, including over 100 species and subspecies of lemur alone.
Unfortunately, human activity is taking its toll on this biodiversity hotspot. Erosion caused by the widespread destruction of forest habitats is silting the rivers, turning them brick red – the color of the soil. While visually striking, it is symptomatic of an ecosystem in distress.
December 9 - 15 2017
A gargantuan dust storm redistributes the sands of a North African desert in this image from August 8, 2014. This large-scale weather system included many cumulonimbus clouds, or thunderstorms, whose characteristic anvil-shaped tops can be seen protruding through the dust-choked base layer.
We share our atmosphere with all who inhabit this planet, and while the greatest and most immediate impact of African dust storms is on the local population, the impact, as it turns out, is not exclusively local. Evidence suggests these storms play a role in the development of tropical cyclones in the Atlantic, which in turn impact the multinational islands of the Caribbean, and the United States gulf coast and eastern seaboard.
African dust intrusions have even been observed in Houston, TX, where the superfluous airborne particles can contribute to respiratory problems, such as asthma.
December 2 - 8, 2017
Hey Everybody, Look at me!
If a volcano could post, the Twitter-verse might have recently exploded with this self-admiring cry for attention.
The pre-eruptive venting of eastern Bali’s Mount Agung, seen in this September 19, 2017, image from the ISS, foretells of the spectacular and purely natural performance which would take place just ten weeks later.
At 5:30 pm local time on Saturday, November 25, plumes of thick volcanic ash spewed from Agung’s central crater. By Sunday the cloud of smoke and ash reached 5.6 miles into the Indonesian skies, forcing thousands of island residents and tourists to evacuate, and air traffic to be either suspended or rerouted.
Agung appears to be on the verge of a more severe, magmatic eruption phase. A powerful eruption could launch ash particles and sulfur dioxide gas into the stratosphere, reflecting sunlight and measurably cooling the entire planet.
According to Balinese tradition, Mount Agung is a replica of Mount Meru, the sacred cosmological mountain at the center of all physical, metaphysical, and spiritual universes.
November 24- December 1, 2017
WHEN CHILE WAS EVEN CHILLIER
Whether you study it for evidence of climate change or hang it on your wall as art, this image of the Southern Patagonian Ice Field is extraordinary. The ice field fills all of Chile’s 8.7 million acre Bernardo O’Higgins National Park and then some. It is a remnant of the much larger ice sheet that covered all of southern Chile during the last glacial period. The terminus of O’Higgins Glacier can be seen protruding into O’Higgins Lake in the lower left of the photo.
In 2007 a glacial lake in the park vanished when pressure from accumulated melt water ultimately destroyed an ancient ice dam. Scientists have linked the accelerated melt rate to climate change.
November 16- November 23, 2017
Hey, Who Let the Air out of the Moon?!
You can thank atmospheric refraction for this droll little optical illusion.
In this image from August of 2016, sunlight reflected off of the Moon’s surface is bent as it passes through Earth’s atmosphere. By the time it arrives at the camera lens peering through the space station’s cupola window, something’s off.
Misshapen, yes. Permanent, no. Light travels fastest through a vacuum, slower through a medium – like air, for example. Where the atmosphere is denser its velocity is somewhat slower, and the light is bent, or refracted. Atmospheric refraction displaces stars from their expected location, and warps the shape of larger objects like the Sun and Moon. These ‘altered states’ are most noticeable just above the horizon, where the atmosphere is densest.
November 11- November 15, 2017
Best. Lightshow. Ever.
Don’t book a room anywhere near Santa’s workshop if your goal is to observe the northern lights overhead. The aurora usually appear as a ring around the earth’s magnetic poles, called an auroral oval, with a diameter of about 2,500 miles. Consider a visit to Alaska, Denmark, or Iceland if it’s straight-up amazing light shows you’re looking for.
The crew of the International Space Station was passing over Mongolia, looking north toward Russia, when this image was taken. Notice the relative positions of the yellowish line that marks the edge of earth’s atmosphere, and the vivid green auroral display. What does this tell us about where in the atmosphere the aurora form?
November 4 - November 10, 2017
Mount Etna – It’s Alive!
Dual vents on Europe’s largest active volcano send plumes of steam in the direction of Riposto, a town along the eastern coast of Sicily. Mount Etna sits above a geologic hotspot, where the African plate subducts beneath the Eurasian plate. The active, 10,922-foot stratovolcano is about 500,000 years old. This image dates from August, 2014.
In 2013 Mount Etna was declared a UNESCO World Heritage site, largely for its “exceptional level of volcanic activity”. In spite of the hazards, about a quarter of the island’s population lives in the volcano’s immediate vicinity. And why wouldn’t they – thanks to Etna the soil is rich and fertile, vineyards and olive groves abound, and tourists spend money with considerable enthusiasm.
The moral of this story – if life gives you lava, make a Mediterranean paradise.
October 28 - November 3, 2017
“You’re old, dusty, gassy and warped. But beautiful. “
Scott Kelly’s words say a lot. He snapped this evocative image of our galactic hometown through the space station’s cupola window in September of 2015. Framed here by the humble forgings of mankind and the elegant arch of earth’s atmosphere, the sheer abundance of solar systems with which we share the neighborhood is breathtakingly apparent.
The fairly long exposure time required for this image – five seconds – accounts for the elongation of the stars, which would otherwise appear as sharp pinpoints of light. Temperature differences produce the wide range of colors seen here, from cooler red stars to hotter blue stars. Our yellowish sun is in the low to mid-range of this scale.
October 20 - 26, 2017
London After Dark
We love our electric lights. In fact, if you want to get a good sense of the population density of any first-world city, just wait for the sun to go down. 8.7 million people inhabit Greater London, and as this image from January of 2017 clearly illustrates, they all own at least one high-intensity light bulb.
Star gazing in these conditions can be frustrating or even impossible, thanks to a phenomenon known as skyglow. Light scattered by the atmosphere above our cities serves as a perpetual night light. Sleep deprivation induced by this relentless exposure has become a significant public health problem in many urban areas.
A grassroots effort known as the dark-sky movement works to raise awareness of, if not shed new light on, the impact of light pollution on people and wildlife.
October 13 - 19, 2017
Great American Eclipse
Our moon is 400-times smaller than our Sun, which the Earth and Moon orbit together. In a purely coincidental fact of celestial geometry, our moon is also 400-times CLOSER to the Earth than is the Sun. Every now and then the tilted orbital planes of the Earth and Moon intersect during a new moon, and the Moon’s elliptical orbit places it at just the right distance. Thus, from our perspective here on Earth, the Moon is centered in front of the Sun at a moment when their apparent sizes are the same. Thank you, 400.
October 6 - 12, 2017
Harvey Approaches the Coast of Texas
“Imagine being on a spaceship, watching this storm barreling down on your family. Fingers crossed for the Gulf Coast.”
Former ISS astronaut Chris Hadfield was referencing the fact that Johnson Space Center in Houston, TX is home to the astronaut corps, as well as their families, when he tweeted these words on August 24, 2017. This image was taken as the ISS flew over Hurricane Harvey prior to landfall on Friday, August 25 at 1:16 PM.
The massive storm came ashore just east of Corpus Christi, TX on Friday night as a Category 4 hurricane. It progressed very slowly once over land, meandering in the direction of San Antonio before heading back into the Gulf of Mexico, northeast to Houston, and eventually into Louisiana. The result was unrelenting rainfall for days, and widespread devastation due to flooding.