([syndicated profile] epod_feed May. 22nd, 2017 03:01 am)


Photographer: Patrick Wiggins
Summary Author: Patrick Wiggins

I made the discovery of this supernova on May 14, 2017, from my home observatory in Utah by comparing images I took that day with one I had taken a few years ago. It's in a spiral galaxy (NGC 6946) located about 22 million light-years from Earth -- the supernova is the bright object blinking on and off at top center. My supernova observation has now been confirmed and given the designation SN 2017aew.While far too faint to be seen with the naked eye, it can be seen with moderate-sized backyard telescopes under dark skies. As I appear to have caught it early (it did not appear on images taken two nights before), it's expected to brighten slightly for a few days before starting to fade and eventually disappearing from view in a few weeks. SN 2017aew has been determined to be a Type II supernova, meaning it was created when a star many times larger than the Sun died in a cataclysmic explosion.
([syndicated profile] epod_feed May. 21st, 2017 03:01 am)

Desert_varnish copy

Each Sunday we present a notable item from our archives. This EPOD was originally published May 22, 2003.

Provided and copyright by: Dan Brownstein

Summary author: Dan Brownstein

This photo clearly shows the interrelationship between the living environment and the geological environment. The vertical stripes are desert varnish, and the rock beneath it is sandstone (possibly Dakota formation?). Unlike moist environments where lichens thrive, dry environments favor the growth of desert varnish. While varnish can contain lichen (a symbiotic form of algae and fungi), it's mainly a type of manganese-oxidizing bacterial colony, combined with a protective layer of locally derived clay. Some desert varnish in the U.S. Southwest can be up to 10,000 years old and has been important in archeological dating. [Revised May 2017]

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([syndicated profile] epod_feed May. 20th, 2017 03:01 am)

EPOD_EncoreTides Near Port Orford, Oregon

Today, and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.


Photographer: Randy Scholten  

Summary AuthorRandy Scholten

December 2011 Earth Science Picture of the Day Viewer's Choice The photo above shows Brush Creek rushing across a wide beach at low tide near Port Orford, Oregon. It was snapped at the base of Humbug Mountain a little past sunset on November 28, 2011. Venus and the waxing crescent Moon are conspicuous in the twilight sky.

Times and amplitudes of the tides are primarily influenced by the alignment of the Sun and Moon. The combined gravitational pull of these bodies when the Moon is full or new create higher amplitude tides than when the Moon is in other phases. Only nine percent of the Moon was illuminated, as shown above, just three days following the onset of the new Moon. A minus 1.2 ft (0.4 m) tide (low tide) was recorded here a few hours after the photo was taken. However, during the new Moon, the low tide was considerably more extreme (referred to as the spring tide), dropping to minus 2.1 ft (0.6 m) with a tidal range of 11.1 ft (3.4 m). [Revised April 2017]

Photo Details: Nikon D700 camera; 20 mm f/2.8D wide angle Nikkor lens; 1/5 sec. exposure; f/2.8; ISO 400. Note that sunset on November 28 was at 4:47 p.m. while moonset occurred at 8:41 p.m.

([syndicated profile] epod_feed May. 19th, 2017 03:01 am)

Strom (1)

Photographer: Rod Benson

Summary Author: Rod Benson

Featured above are fossil stromatolites found along the Highline Trail in Glacier National Park, Montana. The park is made almost entirely of rocks from the Belt Formation (also known as the Belt Supergroup) - layer upon layer of sandstones, shales and carbonates from the late Precambrian Era. At that time, there were no organisms with bones or shells, so stromatolites are the only fossils that can be found in Glacier Park. Fossils of different species of stromatolites can be found in different areas of the park.

Stromatolites are mound-like, multi-layered colonies of algae (blue-green algae or cyanobacteria), and their formation has much to do with the way they change the chemistry of the shallow water where they live. The photosynthetic cyanobacteria remove carbon dioxide from the surrounding water, causing calcium carbonate to precipitate onto their slimy, mat-like colonies. Calcium carbonate, along with grains of sediment (silt, etc.), stick to the biofilm layer that covers the colonies. As the cyanobacteria continue to grow up through the sediment, a new layer forms. This process occurs over and over again, creating layered mounds, columns or sheets.

Stromatolites that lived in the Precambrian played a major role in increasing the amount of oxygen in the atmosphere of the primeval Earth (The Great Oxygenation Event). It should be noted that living stromatolites can be found today at Shark Bay in Western Australia. Photo taken on August 30, 2014.

Photo Details: Camera Maker: Panasonic; Camera Model: DMC-LX7; Focal Length: 4.7mm (35mm equivalent: 24mm); Aperture: ƒ/2.8; Exposure Time: 0.0031 s (1/320); ISO equiv: 80; Software: QuickTime 7.6.6.

Press release Deep biosphere (1)

Photographer: Henrik Drake

Summary Author: Henrik Drake

The photo above features calcite crystals precipitated in response to microbial activity deep within the Earth's crust -- shown in fractured granitic rock in Sweden. These crystals (about 5 mm in height) act to provide an archive for tracking ancient microbial activity. The tweezers are included for scale.

Methane-munching microbes, an analog for extraterrestrial life, have been living in the deep biosphere for some 400 million years. The knowledge about ancient life in the environment deep under our feet is extremely scarce. In numerous cracks down to depths of 1700 m (5,577 ft) that have been partly sealed by crystals growing within them, an international team of researchers led by Dr. Henrik Drake from Linnaeus University, Sweden, have traced fundamental, ancient microbial processes, including the production and consumption of the greenhouse gas, methane. This is thus far the most extensive study on ancient microbial activity in the continental crust, and findings suggest that microbial methane formation and consumption are widespread in the bedrock here.

This new knowledge of a deep source and sink for methane calls for a re-evaluation of the carbon cycling within the vast continental crust and may even be significant in a long-term global warming perspective. Dr. Christine Heim of University of Göttingen, Germany, a co-author of the study, states that it's intriguing to find biomarkers of ancient organic remains having surface origins (land plants) preserved within calcite at such great depth. The nutrient source for the microbes at least partly seems to have been coming from the surface. This connection to the surface biosphere may explain why the marks of microbial activity abruptly disappear at around 700 to 800 m in depth. So in essence, cracks in the Earth's crust and on other planets, believed to be omnipresent, may be the perfect graveyards for past biologic activities.

Photo Details: Camera Maker: SONY; Camera Model: DSC-RX10; Lens: 24-200mm F2.8; Focal Length: 8.8mm (35mm equivalent: 24mm); Aperture: ƒ/2.8; Exposure Time: 0.017 s (1/60); ISO equiv: 125; Software: Adobe Photoshop Lightroom 6.8 (Windows). 


([syndicated profile] epod_feed May. 17th, 2017 03:01 am)



Photographer: Ray Boren

Summary Author: Ray Boren

The landscapes seem so very different. Yet the ridges of California’s rugged Anza-Borrego Desert State Park, about 90 miles (145 km) east of San Diego, and the glacier-carved Sierra Nevada farther north — a range renowned for scenic wonders like Yosemite and Kings Canyon National Parks — have a common core. Both are batholiths formed by intrusive igneous plutons that rose and cooled deep within the Earth between 80 and 220 million years ago. Due to tectonic collisions on the western fringe of North America, the rock masses eventually surfaced as what we see today as the Golden State’s arcing granite spine.

In the photo above, taken on March 27, 2017, a granite slope, shattered by weathering called exfoliation, rises above the Montezuma Valley Road (San Diego County S22), west of Borrego Springs, California. The scene sparkles with the sunny blossoms of brittlebrush (Encelia farinosa), while taller ocotillos (Fouquieria splendens), with their red tips, reach for the blue sky. After years of extreme drought, comparatively luxuriant winter and spring rains turned Anza-Borrego into a flowery wonderland. Other blooming plants ranged from desert dandelions to colorful cacti.

The Peninsular Ranges batholith of southwestern California surfaced to form Anza-Borrego’s north-south backbone. The state park — California’s largest, encompassing 600,000 acres — also includes Colorado Desert valleys, canyons, badlands, and an occasional oasis featuring fan palms (Washingtonia filifera), the only palm tree native to the Western United States. Anza-Borrego is also home to rare peninsular bighorn sheep, which give the park part of its name. Borrego is a Spanish word for sheep. In a second photo, taken on the same day and route, a ram strolls a ridgeline. Anza honors Juan Bautista de Anza, a Spanish explorer who pioneered an overland emigrant route through these mountains in 1774. 

Photo Details: Top - Camera Model: NIKON D3200; Lens: Tokina AT-X 124 AF PRO DX II (AF 12-24mm f/4); Focal Length: 24mm (35mm equivalent: 36mm); Aperture: ƒ/11.0; Exposure Time: 0.0020 s (1/500); ISO equiv: 280. Bottom - same except: Lens: Sigma 150-500mm F5-6.3 DG OS APO HSM; Focal Length: 500mm (35mm equivalent: 750mm); ISO equiv: 220.

([syndicated profile] epod_feed May. 16th, 2017 03:01 am)

Different types of fruit trees   Almond trees in rocky terrain (2)

Photographer: Menashe Davidson

Summary Author: Menashe Davidson

Tree WallShown above are three almond trees I observed while walking among the Eked Antiquities in Ayalon Canada Park, Israel. This fortress dates to the second century BC. The trigger for my taking this little walk was to enjoy the opening of the almonds gentle white blossoms.

At left are three ancient fruit trees found growing in and around the fortress; a fig tree, an olive tree (evergreen) and an almond tree  (from left to right). These three fruiting trees have been a staple food for humans for thousands of years and were among the first to be cultivated. Their fruit, rich in nutritional value, can be eaten fresh or preserved as dried fruit or as processed oil.


  • Almond (Amygdalus communis, family Rosaceae) - is one of the species most common in the Mediterranean woodlands of Israel. It's a deciduous tree that is among the first to flower, presaging the arrival of spring. Flowering precedes the appearance of foliage.
  • Olive (Olea europea, family Oleaceae) - an evergreen tree found across much of the Mediterranean region. It's mentioned numerous times in the Bible and is common throughout Israel.
  • Fig (Ficus carica, family Moraceae) – a deciduous tree, like the olive, is an integral part of the landscape and agriculture of the eastern Mediterranean region. Both photos taken on February 6, 2017.

Photo Details: Camera Model: NIKON D7100; Focal Length: 26mm (35mm equivalent: 39mm); Aperture: ƒ/25.0; Exposure Time: 0.010 s (1/100); ISO equiv: 250.


([syndicated profile] epod_feed May. 15th, 2017 03:01 am)

Okefenokee Tea (2)

Photographer: Rob Sheridan

Summary Author: Rob Sheridan

At nearly 700 sq mi (438,000 acres or 1,770 sq km), Georgia’s Okefenokee is the largest blackwater swamp in North America. An average of 50 in (127 cm) of rain a year saturate this peat-filled shallow bedrock depression formed from a relic of a Pleistocene estuary on Atlantic Coastal Plain. Although quite pristine, the average 2 ft (60 cm) depth of Okefenokee water is stained tea-colored by tannins released by vast amounts of decomposing vegetation.

Two natural outlets release this blackwater to the sea. About 10 percent flows via the St. Mary’s River to the Atlantic in southeast Georgia. The major drainage is via the Suwannee River (made famous by songwriter Stephen Foster, despite never having visited the area) through northeast Florida into the Gulf of Mexico. In this photo, at a bend in the Suwannee within Florida’s Stephen Foster Cultural State Park, a bottle of clean Suwannee blackwater tea is held in the foreground. Also seen are bald cypress trees that have evolved with root systems that thrive semi-submerged. Designated as both a National Wildlife Refuge and a National Natural Landmark, the warm, humid Okefenokee supports an enormous diversity of plant, insect, and animal life -- it's an off the beaten track U.S. treasure. Photo taken on February 23, 2017.

Photo Details:  Camera Maker: NIKON; Camera Model: COOLPIX S9700; Focal Length: 4.5mm (35mm equivalent: 25mm); Aperture: ƒ/3.7; Exposure Time: 0.0031 s (1/320); ISO equiv: 125;

Software: Adobe Photoshop Elements 14.0 (Windows).

([syndicated profile] epod_feed May. 14th, 2017 03:01 am)


Each Sunday we present a notable item from our archives. This EPOD was originally published May 13, 2003.

Provided by: Earth Observatory, NASA GSFC

Summary authors & editors: Earth Observatory; Jim Foster

The above image was acquired by the Landsat-7 Enhanced Thematic Mapper plus (ETM+) sensor on August 14, 1999. This is a natural color composite satellite image made using red, green, and blue wavelengths. The islands and coral reefs that form the Great Barrier Reef resemble misshapen blue pearls, stretching more than 2,000 km (1,200 miles) along the Queensland coast of Australia (at left). In October of 1981, the Great Barrier Reef was inscribed on the World Heritage List. It's the world's most extensive reef system, and the biggest structure made by living organisms on Earth. To the north, the reef is virtually continuous, while in the south (as shown above), individual reefs are more common.

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([syndicated profile] epod_feed May. 13th, 2017 03:01 am)

EPOD_EncoreGreat Aletsch Glacier (2)

Today, and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.


Photographer: Piero Armando

Summary Authors: Piero Armando; Jim Foster

December 2011 Earth Science Picture of the Day Viewer's Choice The photo above showing the sinuous Aletsch Glacier was captured from near the summit of Eggishorn (9,600 ft or 2,926 m), in the eastern Bernese Alps. The Aletsch Glacier is the longest glacier in the Alps Mountains, stretching to a length of nearly 14 mi (23 km). Note the chalky band of rock between the glacial ice and the zone of vegetation (green) on the far side of the valley -- clear evidence that this glacier is in retreat. Between 2005 and 2006 alone, the Aletsch Glacier receded approximately 330 ft (100 m). Medial moraines, formed when glaciers merge, line the Aletch Glacier. The debris signature of such mergers is often carried many miles downstream. Photo taken on July 20, 2010.

Photo Details: Canon EOS 30D camera; 17mm focal length; f/11.0 aperture; 1/250 sec. exposure; ISO equivalent 100; sRGB color space; two separate exposures stitched together.

([syndicated profile] epod_feed May. 12th, 2017 03:01 am)


Photographer: Patti Weeks

Summary Author: Patti Weeks

Visitors to San Francisco, California, expect to see hilly terrain but might be surprised to see a tree-covered hill popping up 575 ft (175 m) in the middle of the city, as seen in this photograph. Buena Vista Park is the oldest park in San Francisco, established in 1867. Once a barren, dune-like sandy hill, it’s now lush with vegetation and provides walking trails, recreational areas and remarkable views of the city. Of the park’s 36 acres, six of them comprise the northern Natural Area and contains one of San Francisco’s most expansive forests of native coast live oaks. But the park also contains non-native trees and plants, introduced from Europe as early as the 1700s. Around 40 percent of the flora in San Francisco is non-native, much classified as invasive. Invasive species tend to choke out native species and threaten entire ecosystems.

Hard to imagine, but much of the of the San Francisco Bay surface area was once covered in massive sand dunes: bare dunes that were in continual motion on the western Pacific side, and the more stable dune scrub on the eastern bay side. Coastal dune scrub is a deep-rooted, native plant community that survives the harsh conditions of the battering winds and sea salt air and aids dune stabilization.

In the first few years of the burgeoning California Gold Rush (1848–1855), builders and real estate speculators began leveling the tall hills of deep sand and moving thousands of tons of the dunes. For decades they filled the surrounding tidal marshes in the bay with the sand to create land for sale for the growing population of colonial settlers. The earthquake of 1989, which caused considerable damage to the Marina district, proved this undertaking to be a poor idea. Buena Vista Park is one of the dunes in San Francisco that was spared leveling and transportation.

This photo was taken on an uncharacteristic fog-free day from the 922-ft (281 m) Twin Peaks overlook. To the right of Buena Vista Park in the photo is the western edge of downtown San Francisco. Seen almost directly behind the park, isolated in the San Francisco Bay, is the island of Alcatraz, site of the infamous federal penitentiary. Nicknamed The Rock, Alcatraz Island is now a National Historic Landmark.

Photo Details: SONY DSC-HX400V camera; 24–210 mm lens, ƒ/2.8–6.3; 18.55 mm focal length; ƒ/5 aperture; 1/2000 sec. exposure time; ISO 200.

([syndicated profile] epod_feed May. 11th, 2017 03:01 am)

Everest_DSC_2136-Recovered-copy (3)

Photographer: Konstantinos Vasilakakos

Summary Author: Konstantinos Vasilakakos

Shown above is the crown of the Himalayas, Mount Everest, Nepal. Standing  29,029 ft (8,848 m) above the level of the sea, it's the highest point on Earth. After two failed attempts for the summit of Everest, also known as Qomolangma, George Mallory traveled to America in 1923 to tell about his adventures at the Explorers Club of New York. There, he told them about the biting wind, the lack of appetite, the furious cold. A New York Times journalist asked the question: Why climb Everest? Mallory gave his legendary reply, ''Because it's there."

To get this picture I traveled with a dedicated group of people who like me longed to see the top of the world. We left Lhasa, the Tibetan capital, covering a tiring journey of about 250 mi (400 km) to New Tingri. After going through Gyatso la Pass, we were finally able to see Qomolangma. It was a beautiful and but eerie scene, the pinnacle of our planet, bathed with light just before nightfall. I remember turning my head back to see the rest of the group. Some people were left with their mouth's open, others were weeping and some furiously setting up cameras.

Featured here is the North Face of Everest; the same face where Mallory made his three attempts to reach the top of the world. Powerful winds, likely in excess of 80 mph (70 knots) are blasting the peak. For anyone daring dreams, make the journey to Qomolangma. Photo taken on April 11, 2015.

([syndicated profile] epod_feed May. 10th, 2017 03:01 am)

Fitz Roy_16387011_10210158064862194_6816903609243540110_n (1)

Photographer: Melina Catania

Summary Authors: Melina Catania; Jim Foster

The photo above showing Mount Fitz Roy (Monte Chaltén), on the border of Argentina and Chile, looks like it could be a mountain in a fairytale land. Located to the east of the Southern Patagonian Ice Field, Fitz Roy's abrupt peak reaches 11,171 ft (3,405 m) above sea level. Though it's only about half the height of South America's tallest mountain, Aconcagua, because it's so steep and remote, Fitz Roy wasn't scaled until 1952, just a year before Mount Everest (29,029 ft or 8,848 m) was first climbed. The name Chaltén evidently comes from the Tehuelche (Aonikenk) language and means steaming mountain, a reference to the clouds that seem to surround the legendary summit constantly. Photo taken on January 22, 2017.

([syndicated profile] epod_feed May. 9th, 2017 03:01 am)

Boston-moonrise-41117 (3)

Photographer: Chris Cook

Summary Authors: Chris Cook; Jim Foster

As shown above, April's full Pink Moon rises behind the skyline of Boston, Massachusetts. While April's full Moon is called the Pink Moon for the wild ground phlox flower that blooms during the spring in much of the U.S. and Canada, this Moon rose a vivid reddish/orange color. When the Moon (or Sun) is near the horizon, it typically looks reddish since the optically thicker atmosphere scatters out the shorter wavelengths of light (blues and greens). However, dust, haze and pollen (from flowering trees) also contribute to atmospheric scattering. Because of the warm spring temperatures in the eastern U.S. this year (April was 7 degrees F above normal at many locations), and rather dry conditions, a number of different tree species were flowering and released their pollen at nearly the same time. Thus, pollen counts were particular high. Look for the color of the rising full Moon tomorrow night (Flower Moon). Photo taken on the evening of April 11, 2017.

Photo Details: Camera Model: Canon EOS 6D; Lens: TAMRON SP 150-600mm F/5-6.3 Di VC USD A011; Focal Length: 600mm; Aperture: ƒ/6.3; Exposure Time: 0.600 s; ISO equiv: 2500; Software: Adobe Photoshop CC (Windows).