• ES Picture of the Day 29 2020

    From Black Panther@21:1/186 to All on Wed Jan 29 14:01:02 2020
    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.


    Crown-of-Thorns Starfish

    January 29, 2020

    CrownofThorns_AZ7Y7393_acanthaster_planci (003)

    Photographer: Martin Dietzel
    Summary Author: Martin Dietzel

    While walking along the shoreline of the Dhaalu Atoll in the
    Maldives, I came upon this odd type of starfish (sea star) that
    IΓÇÖd never seen before. Its purple color was really remarkable. I did a
    little research and realized that this must be a crown-of-thorns
    starfish (species Acanthaster planci). IΓÇÖm glad I didnΓÇÖt make an
    effort to catch one since its spiky surface can release toxins if
    handled, inflicting pain and possibly infection.

    The crown-of-thorns is huge ΓÇô itΓÇÖs one of the worldΓÇÖs largest
    starfish. This specimen had a diameter of approximately 16 in (40 cm).
    Looking around, I noticed several others, but they were in slightly
    deeper water, atop pieces of coral. In fact, they feed on coral and
    have been known to cause considerable damage to coral reefs. Photo
    taken on September 28, 2019.
    * Dhaalu Atoll, Maldives Coordinates: 2.8469, 72.9461

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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

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  • From Black Panther@21:1/186 to All on Sat Feb 29 14:01:26 2020
    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.


    Analemma from Albusciago, Italy

    February 29, 2020

    Analemma2016 (1)

    Photographers: Paolo Bardelli; Luca Carlana
    Summary Authors: Paolo Bardelli; Luca Carlana

    Our Planet makes a complete turn around the Sun in 365.2422 days.
    On average, one day (29 February) is added to the calendar every
    4-years to catch up with this small delay. Like 2016, 2020 is a
    leap year.

    Four years ago, Luca and I decided to photograph the Sun every day at
    noon (local time), from Albusciago, Italy. We were able to get 245 out
    of 366 useful shots (67 percent). The sum of these images produces the
    figure 8 form called an analemma. This is because the
    Earth's orbit is elliptical and not circular, the speed is not
    uniform ( Kepler's laws) and the rotation axis is inclined
    by 23 degrees.

    To photograph this analemma, we used a digital camera in an automated
    fixed location with a programmable electronic board. From a fairly
    complete analemma one can derive a considerable amount of information
    (for example, the positions of equinoxes and solstices, the
    symmetry of the seasons, etc.). The apparent motion of the Sun is
    faster towards the Northern HemisphereΓÇÖs spring and autumn but is
    almost zero in June.

    Note that the path (apparent path) of our home star is in front of
    the constellations of the Zodiac. By the way, there are 13
    constellations of the Zodiac, not 12. The thirteenth constellation is
    Ophiuchus, nestled between Scorpio and Sagittarius.

    Photo Details: Canon 350d camera, zoom lens18/55 mm; 18 mm; with
    Astrosolar filter. Sum of 245 images - 1/250 second exposure; f/5,6,
    400 ISO; Photoshop CC (Windows). Hardware and processing: Paolo
    Bardelli; Software: Luca Carlana.
    * Albusciago, Italy Coordinates: 45.7395, 8.7939

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    Sun Links

    * NASA Solar Dynamics Observatory
    * NASA Solar Eclipse Page
    * NOAA Solar Calculator
    * The Sun-Earth Connection: Heliophysics
    * The Sunspot Cycle
    * Solar System Exploration: The Sun
    * The Sun Now
    * This WeekΓÇÖs Sky

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

    https://epod.usra.edu

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  • From Black Panther@21:1/186 to All on Sun Mar 29 13:05:52 2020
    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 - Eureka Dunes in Death Valley, California

    March 29, 2020

    Eureka Dune - Death Valley - 22 Oct 2012 - (2)

    Each Sunday we present a notable item from our archives. This EPOD was
    originally published 3/31/2014.

    Photographer: Stephen Gledhill
    Summary Authors: Stephen Gledhill; Jim Foster
    This panorama shows nearly the entire length of the 3 miles (4.8 km)
    long Eureka Dunes (beige colored landform) found in Death
    Valley, California. It was taken about 25 minutes before sunrise on
    October 22, 2012. Eureka Dunes, composed chiefly of well-sorted
    medium-sized (0.33 mm diameter) sand grains, are one of the tallest
    dune complexes in North America. The highest point climbs some 680
    ft (207 m) above the floor of an ancient lake bed, thought by some
    geologists to have been the primary source of the sand that forms the
    dunes. On occasion, a strange humming sound comes from the dunes.
    This singing is believed to result when loosely packed, spherical
    sand grains avalanche down the dune's steep faces.
    Photo Details: Canon 7D camera; on tripod; zoom lens; focal length of
    38mm; 5 frames stitched together.
    * Eureka Dunes, California Coordinates: 37.096, -117.675

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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
    * 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

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  • From Black Panther@21:1/186 to All on Wed Apr 29 13:03:28 2020
    https://epod.usra.edu

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  • From Black Panther@21:1/186 to All on Fri May 29 15:02:00 2020
    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.


    Twilight Times: Civil, Nautical and Astronomical

    May 29, 2020

    MarcoM_twilight

    Photographer: Marco Meniero
    Summary Authors: Marco Meniero; Jim Foster

    The photos shown above demonstrate how the amount of light changes
    during the progression of twilight. They were taken at the Viterbo
    Airport Control Tower in Italy, on May 8, 2020. I pointed the camera
    optics towards the town of Montefiascone, which from my position is to
    the north. The first photo, at lower left, was taken at 13:00 or 1:00
    p.m. ( local time), then in counterclockwise order at 8:19 p.m.
    ( sunset and beginning of the civil twilight), at 8:50 p.m.
    (beginning of nautical twilight) and at 9:29 p.m. (beginning of
    astronomical twilight). Once the Sun dips more than 18 degrees
    below the horizon, twilight brightness approaches zero -- considered
    the beginning of nightfall.
    * Viterbo Airport, Italy Coordinates: 42.43611, 12.06166

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    Atmospheric Effects Links

    * Atmospheric Optics
    * 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

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  • From Black Panther@21:1/186 to All on Mon Jun 29 15:02:54 2020
    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.


    Bioluminescence off Southern California

    June 29, 2020

    2020-05-03_231351_IMG_6238_c

    Photographer: Matt Read
    Summary Author: Matt Read

    For several weeks in April and early May (2020), Southern California
    experienced an extensive red tide algal bloom. By day, the
    water appears rusty colored, but by night, the dino-flagellates
    responsible for the bloom, in this case, the phytoplankton named
    Lingulodinium Polyedra, exhibit bright blue bioluminescence
    when agitated.

    My daughter, a marine biologist, and I went to see the nocturnal glow
    in person, near the Scripps Institution of Oceanography, in La
    Jolla, California. The pier in the image belongs to Scripps, which is
    affiliated with the University of California at San Diego (UCSD).
    This pier is closed to the public, but Scripps operates the Birch
    Aquarium, just up the hill from here, which primarily exhibits marine
    flora and fauna from Southern California.

    In the picture, other fans of bioluminescence are observing social
    distancing guidelines while enjoying the display. The bioluminescent
    flashes occurred only as waves first broke. Also glowing in this image
    is the bright star Capella, near the upper right corner. Photo
    taken May 3, 2020, at 11:13:51 p.m.

    Photo Details: Camera: Canon EOS 80D; Software: Adobe Photoshop CS4
    Windows; Exposure Time: 6.000s; Aperture: ƒ/8.0; ISO equivalent: 3200;
    Focal Length: 24.0mm; Lens: EF-S15-85mm f/3.5-5.6 IS USM.
    * Scripps Pier, California Coordinates: 32.86585, -117.25454

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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

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  • From Black Panther@21:1/186 to All on Wed Jul 29 15:00:30 2020
    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.


    River Bussento in Southern Italy

    July 29, 2020

    IMG_2188-Modifica-Modifica

    Photographer: Fabio Di Stefano
    Summary Author: Fabio Di Stefano
    In the region of Campania, Italy, it's possible to witness an oasis
    of the Bussento River. This river has perhaps the longest
    subterranean course in southern Italy. It returns to the surface in
    the so-called Bussento's cave, after flowing some 2.5 miles (4 km)
    underground. Over time, rainfall has infiltrated the limestone rock
    of this region creating a karst topography that on occasion permits
    water flowing at the surface to disappear, usually re-emerging a short
    distance later. However, in some cases, river flow is subterranean for
    more than 20 miles (32 km). Photo taken on July 19, 2019.

    Photo Details: Camera - Canon EOS M6; Software - Adobe Photoshop
    Lightroom Classic 9.1 (Windows); Exposure Time - 0.0050s (1/200);
    Aperture - ƒ/7.1; ISO equivalent - 800; Focal Length - 11.0mm.
    * Grotte del Bussento Oasis, Italy Coordinates: 40.14054,
    15.55297

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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

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  • From Black Panther@21:1/186 to All on Sat Aug 29 15:00:30 2020
    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.


    Encore - Altair and Barnard's "E"

    August 29, 2020

    Altair_Wide_Field_60pc
    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: Greg Parker
    Summary Authors: Greg Parker; Jim Foster

    October 2014 Viewer's Choice Shown above in this extreme wide-field
    view (10 x 7 degrees) of the summer sky is the central region of the
    constellation of Aquila the Eagle. The bright star at left center
    is Altair, the brightest star in Aquila. Alshain is below
    Altair and Tarazed above it -- the second and third brightest stars
    in Aquila, respectively. The very dark portion of the sky, just to the
    right of Tarazed, is known as Barnard's "E." It consists of two
    dark nebulae (dust and gas clouds) approximately 2,000 light
    years distant.
    Altair also forms the southernmost star in the Summer Triangle.
    This conspicuous Isosceles triangle is still visible during the
    Northern Hemisphere's autumn season, in the southwestern sky, soon
    after sunset.
    Photo Details: Canon 5D MkII camera; DSLR and 200 mm lens were
    piggy-backed on a Celestron Nexstar 11 GPS telescope for tracking.
    Images were taken at ISO 400 and f/4 with a Hutech IDAS light pollution
    filter fitted to the front of the 200 mm lens. Exposures were 4 minutes
    with a total of 24 exposures (subs). RAW data-files expertly processed
    by Noel Carboni, in Florida, U.S.A.
    * New Forest Observatory, U.K. Coordinates: 50.819444, -1.59

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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

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  • From Black Panther@21:1/186 to All on Tue Sep 29 15:00:46 2020
    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.


    EPOD 20th - Diatom Wreath

    September 29, 2020

    Diatom_Plankton%20portland%20120418%20eucampia%20zoodiacus%20

    December 2018 Viewer's Choice We’re celebrating 20 years of Earth
    Science Picture of the Day during the month of September! Today’s photo
    features a popular EPOD from the past. Thanks to all of our followers
    (on the blog, Facebook, Instagram and Twitter) for supporting us.
    Thanks also to all of you who’ve submitted your photos. We’re most
    appreciative. This EPOD was originally published December 24, 2018.

    Photographer: Southern Maine Community College Photography Class
    Summary Author: John Stetson

    This wreath is certainly festive and seasonal, but it's just a bit too
    small, about the width of a human hair, to place on the front door
    to welcome guests. It's made from a common species of diatom
    ( Eucampia zodiacus). Why can diatoms look so much like stained
    glass windows in a Cathedral? They're made from opaline silica,
    SiO2 -- the material of opals and glass.

    Diatoms are critically important in that they're the beginning of the
    food chain. Aquatic plants (of which diatoms are the most
    prolific) supply 50 percent of the oxygen on Earth, and when they
    die they sink to the bottom of the oceans, acting as a carbon sink.
    Photo taken on December 2, 2018.
    * Southern Maine Community College, Maine Coordinates: 43.64,
    -70.242

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    Plant Links

    * Discover Life
    * Tree Encyclopedia
    * What are Phytoplankton?
    * Encyclopedia of Life - What is a Plant?
    * USDA Plants Database
    * University of Texas Native Plant Database
    * Plants in Motion
    * What Tree is It?

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

    https://epod.usra.edu

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