EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Great Salt Lake’s Mirabilite Mounds

March 23, 2022

GSLmirabsalt876c_01feb22
GSLmirabsalt876c_01feb22

Photographer: Ray Boren

Summary Author: Ray Boren

Due to long-term drought, exposed shorelines of the Great Salt Lake
are in places speckled with crystalline hummocks that resemble the
larger terraced springs of Yellowstone National Park. Unlike the
national park’s travertine-lined hot springs, however, the Utah
phenomena are mirabilite mounds. These unique landforms take shape
over the cold winter months and when shoreline water has withdrawn
enough to reveal usually submerged springs.

This process has been the case for the past few years, notably on the
south shore beach at Great Salt Lake State Park and Marina, as
illustrated in the above photographs taken on February 1, 2022. The
first photo shows several mounds, with the lake’s edge and
Stansbury Island in the distance, while the second picture is a
closeup of one of the formations.

A layer of sodium sulfate underlies the lakebed surface, so when
spring water rises in the winter cold, mirabilite crystals effloresce
upon exposure. This crystallization process creates the mounds and
their sequences of small terraces. The mineral mirabilite — from the
Latin “sal mirabilis” for “wonderful salt” — is found in saline
lakes and on playas around the world. The rare mounds around Great Salt
Lake are not composed of sodium chloride, also known as common table
salt (NaCl), but instead of hydrated sodium sulphate
(Na2SO4•10H2O). This compound is also called Glauber’s salt and has
various medical applications.
* Great Salt Lake, Utah Coordinates: 41.115, -112.476

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Great Salt Lake’s Mirabilite Mounds La Cascata di Fondo and
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Hydrology Links

* Current Sea Surface Temperature
* NOAA Ocean Explorer Gallery
* Ocean Color
* What is hydrology?
* Tides and Currents
* Water Resources of the United States
* World Waterfall Database
* The USGS Water Science School
* World Water Database
* The World’s Water
* USGS Surface Water Information Pages

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 3 weeks, 2 days, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Archive - Great Sand Dunes National Park

April 23, 2022

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Every weekend we present a notable item from our archives.

This EPOD was originally published on December 9, 2011.

Photographer: Ingrid Wood
Summary Author: Ingrid Wood; Jim Foster
The photo above shows the massive tan-colored dunes in Great
Sand Dunes National Park and Preserve, Colorado. Hikers in the
foreground give scale to the immense size of these windblown sand
dunes, which reach up to about 750 ft (230 m) above the surrounding
landscape -- perhaps the tallest in North America. These dunes cover
some 39 sq mi (100 sq km) and over thousands of years have settled up
against the windward flank of the Sangre de Cristo Mountains,
pushed by prevailing southwest winds across the San Luis
Valley. The source of the sand was a widespread sand sheet, sand
left behind when ancient lakes dried up, in the central portion of the
San Luis Valley. Photo taken on August 22, 2007.

Photo Details: Camera: Canon PowerShot A530; Focal Length: 9.8mm;
Aperture: f/7.1; Exposure Time: 0.0031 s (1/320).
* Great Sand Dunes, Colorado Coordinates: 37.73287, -105.51212

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Archive - Great Sand Dunes National Park Drone Image Over Mount
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Rainbow Pyrite
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Geology Links

* Earthquakes
* Geologic Time
* Geomagnetism
* General Dictionary of Geology
* Mineral and Locality Database
* Mohs Scale of Mineral Hardness
* This Dynamic Earth
* USGS
* MyShake - University of California, Berkeley
* USGS Ask a Geologist
* USGS/NPS Geologic Glossary
* USGS Volcano Hazards Program

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 7 weeks, 5 days, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Supernumerary Rainbow Over Modica, Italy

May 23, 2022

Arcobaleno_verticale_collage_epod

Photographer: Salvatore Cerruto

Summary Authors: Salvatore Cerruto; Cadan Cummings

During the afternoon of February 15, 2022, I was lucky enough to see a
supernumerary rainbow in the sky over Modica, Sicily, Italy.
These unique rainbow arcs are visible below the primary rainbow and
are produced when incoming sunlight is diffracted through very
small raindrops. Resulting from the diffraction process are regions of
light wave interference where the colorful band are from
constructive interference and the colorless gaps are from destructive
interference.

Supernumerary rainbows can be identified by several colored fringes-
ranging from indigo to green- visible below the rainbow that also
appear like the rainbow is repeating itself. To show the optical
phenomenon in greater detail, I enlarged the part that had the
supernumerary arcs and saturated it a little to highlight the
features and colors. This specific composite image is a panorama
composed of eight vertical shots taken using a Nikon DSLR camera with a
35mm lens.
* Modica, Sicily, Italy Coordinates: 36.8588, 14.7608

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Atmospheric Effects Links

* Atmospheric Optics
* Optic Picture of Day: Gruppo Astrofili Galileo Galilei
* Color and Light in Nature
* The Colors of Twillight and Sunset
* Refraction Index
* Image Gallery: Atmospheric Effects
* What is a Rainbow?

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 12 weeks, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Glory Observed Above Sicily, Italy

June 23, 2022


IMG_20220311_145649_3000

Photographer: Salvatore Cerruto
Summary Authors: Salvatore Cerruto; Jim Foster

During a recent plane trip, I was able to observe the glory shown
above while we were landing in Sicily, approaching Catania's
Fontanarossa Airport. Sometimes called the "pilot's glory, these
colorful concentric rings appear on the side of the plane directly
opposite of the Sun. This phenomenon can also be seen from
mountainous areas, if a fog bank lies below you, as colored rings
surrounding the observer’s own shadow.

The glory is formed from diffraction of sunlight by tiny cloud
droplets. When sunlight enters these droplets (approximately 0.0010 –
0.0050 mm in diameter), their small size acts to scatter light
rather than refract or reflect it. Photo taken on March 11,
2022.
* Catania, Sicily, Italy Coordinates: 37.6771210, 14.6250490

Related EPODs

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More...

Atmospheric Effects Links

* Atmospheric Optics
* Optic Picture of Day: Gruppo Astrofili Galileo Galilei
* Color and Light in Nature
* The Colors of Twillight and Sunset
* Refraction Index
* Image Gallery: Atmospheric Effects
* What is a Rainbow?

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 16 weeks, 3 days, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Summertime Fireflies and Star Trails

August 23, 2022

DSC_1228s2

Photographer: Matthew Chin
Summary Author: Matthew Chin
Even though Hong Kong isn’t graced with many green spaces, in a few
locations, such as Sha Lo Tung, we can see vast numbers of
fireflies in late spring and throughout summer. Unfortunately,
their environment is being increasingly destroyed because of various
human activities. As shown above, the bioluminescent trails left by
the little fireflies and the star trails of the summer
constellations have been combined onto one image. Photo taken on August
29, 2017.

Photo details: Nikon D750 camera; 18 mm lens.


Sha Lo Tung, Hong Kong, Coordinates: 22.4794, 114.1823

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Animal Links

* Animal Diversity Web
* ARKive
* BirdLife International
* Bug Guide
* Discover Life
* Integrated Taxonomic Information System
* Microbial Life Resources
Earth Science Picture of the Day is a service of the
-
Universities Space Research Association.

https://epod.usra.edu

--- up 25 weeks, 1 day, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Celestial Parade of the Planets in June 2022

September 23, 2022

0623PlanetsandMoon-3 (1)

DSC_1140s2 (1)

Allineamento Planetario Tranego 7-4

Photographers: Matthew Chin; Meiying Lee; Alessandra Masi

Summary Authors: Meiying Lee; Matthew Chin; Alessandra Masi

Featured above are views of the visible planets in our solar
system, and the crescent moon, as seen from Taipei (top), Yuen
Long, Hong Kong (middle) and the Dolomite Range of Italy (bottom,
note that Neptune and Uranus are also visible here). Such an
unusual alignment can be observed only about once every 20-years.
Top and middle photos were taken on June 23, 2022, and the bottom photo
was taken on June 25, 2022. All photos were captured looking east, just
before dawn.


Yuen Long, Hong Kong Coordinates: 22.4445, 114.0222

Taipei, Taiwan Coordinates: 25.0330, 121.5654

Dolomites Mountains, Italy Coordinates: 46.433334, 11.850000


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Celestial Parade of the Planets in June 2022 Supermoon and
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SN2022hrs
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Night Sky Links

* Space Weather Live
* Space Weather Live Forum
* About the Moon
* American Meteor Society
* Arbeitskreises Meteore e.V.
* Global City Lights
* Heavens Above Home Page
* The International Meteor Organization
* Lunar and Planetary Institute
* MoonConnection
* NASA Eclipse Web Page
* Understanding The Moon Phases

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 29 weeks, 4 days, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Saturn's Rings in 2020, 2021 and 2022

November 23, 2022


Astro_by_sona (5)
Photographer: Sona Shahani
Summary Author: Sona Shahani

Shown above is a compilation of images featuring Saturn and its
ring system in 2020, 2021 and 2022. The most recent image was taken
on June 25, 2022. Saturn’s axial tilt is 27 degrees, and from our
perspective we see the rings present themselves differently every
year. Reflection from Saturn’s rings slightly increases how bright
Saturn appears to us. However, even when the “ringed planet” is at
maximum tilt, we’re unable to detect the rings with the naked eye. All
photos observed from New Delhi, India.

Photo details: 8" Skywatcher Flextube Dobsonian telescope; ZWO
ASI178MC; 2.5X; Televue Powermate; EQ Platform; SvBony UV/IR Filter;
Captured in Shaprcap; stacked in ASi3; Wavelets in Registax and fine
tuning in Photoshop.

New Delhi, India Coordinates: 28.6139, 77.2090


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Night Sky Links

* Space Weather Live
* Space Weather Live Forum
* About the Moon
* American Meteor Society
* Arbeitskreises Meteore e.V.
* Global City Lights
* Heavens Above Home Page
* The International Meteor Organization
* Lunar and Planetary Institute
* MoonConnection
* NASA Eclipse Web Page
* Understanding The Moon Phases

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 38 weeks, 2 days, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)

EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


Halo Display Observed from Graubunden, Switzerland

December 23, 2022


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Photographer: Sean Lybrand
Summary Author: Sean Lybrand

Shown above is a portion of halo display I had the pleasure to
observe over the Swiss Alps on October 11, 2022. Ice crystals in
clouds or free falling through the atmosphere can create a medley of
beautiful halos; some very obvious and some quite faint.

Conspicuous here are the 22-degree halo, both sundogs or
parhelia, the parhelic circle, the upper tangent arc (tangent
to the 22-halo) and the suncave Parry arc (just above the upper
tangent arc). Not nearly as evident are the rarely seen upper and lower
Lowitz arcs (in the vicinity of the parhelia).


Sent, Graubunden, Switzerland. Coordinates: 46.81016, 10.34032


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Atmospheric Effects Links

* Atmospheric Optics
* Optic Picture of Day: Gruppo Astrofili Galileo Galilei
* Color and Light in Nature
* The Colors of Twillight and Sunset
* Refraction Index
* Image Gallery: Atmospheric Effects
* What is a Rainbow?

-
Earth Science Picture of the Day is a service of the Universities
Space Research Association.

https://epod.usra.edu

--- up 42 weeks, 4 days, 22 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)