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.


Ice Patterns on Binnewater Lake

February 17, 2020

Binnewater Lake Ulster CO NY ice small

Photographer: Daniel Spitzer
Summary Authors: Daniel Spitzer; Jim Foster

These attention-getting patterns in lake ice were observed over
Binnewater Lake, New York on January 24, 2020. This photo was taken
from a small (2 seat) plane. The ice was in the process of melting.
Trying to explain all of the odd ice patterns seen on lakes and ponds,
even on puddles, is challenging since so many factors play a role, many
that aren’t at all obvious at first glance.

In most years, lake ice doesn’t freeze evenly so it regularly contracts
and expands throughout the season. Initially, a hard freeze perhaps
caused the ice to contract, forming the cracks. The circular ring
pattern shows that the primary source of the stress was radial. A small
upflow hole in the ice is where the ring pattern originated. As the ice
began to melt, open water rose through the cracks and after another
freeze this water froze and expanded. This process was repeated
with additional thaws and freezes. Presumably, the ice further from
shore was thinner, so more readily cracked. Note also the pond
stars close to shore.

Photo Details: Camera: LEICA SL2; Software: Adobe Photoshop CC 2019
(Macintosh); Exposure Time: -1717986s (1/0); Aperture: ƒ/4.0; ISO
equivalent: 400; Focal Length (35mm): 280.
* Binnewater Lake, New York Coordinates: 41.8978, -74.0583

Related EPODs

Ice Patterns on Binnewater Lake Mid-air Icicle Ice Ovals in
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Ice Pattern on Pond Snowflake Sampler
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Cryosphere Links

* Guide to Frost
* What is the Cryosphere?
* Bentley Snow Crystals
* Glaciers of the World
* Ice, Snow, and Glaciers: The Water Cycle
* The National Snow and Ice Data Center Google Earth Images
* Snow and Ice Crystals

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

https://epod.usra.edu

--- up 3 weeks, 6 days, 45 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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.


Quadrantid Meteor Shower

January 17, 2020

QuadrantidsRodokiposAA

Photographer: Constantine Emmanouilidi
Summary Authors: Constantine Emmanouilidi; Jim Foster

Shown above is a composite of the meteors I observed from
Rodokipos, Halkidiki, Greece during the Quadrantid meteor
shower in the early morning hours of January 4, 2020. Although the cold
temperatures (27 F or -3 C) and moonlit skies were certainly a
deterrent, because the night was crystal clear I decided to make the
effort to get up early to set up my equipment and was certainly glad I
did. When I arrived at my observing location, after a one-hour drive, I
immediately knew that this would be a very active meteor shower. As
usual for me when observing a wintertime meteor shower, I dressed in
many warm layers, found a comfortable place to lay down and made sure I
had plenty of warm tea. I had my watch with me to measure the
zenith hourly rate or ZHR.

I started imaging in earnest at 01:30 UT, finishing as the Sun
rose. During the night there were several periods of bursts of activity
and longer intervals with very little action. Only the brightest
meteors are shown here -- a number of shooting stars were too faint to
image with my camera. I took more than 700 images and after eliminating
the images with satellite overpasses, a tedious task, I measured a
maximum ZHR of 125 meteors at approximately 03:40 UT. Notice that these
meteors appear to be coming from a specific area of the sky; this is
the radiant. For the Quadrantids, the radiant is in the northern
portion of the constellation of Boötes.
* Rodokipos, Greece Coordinates: 40.3556, 23.1322

Related EPODs

Quadrantid Meteor Shower Encore - Lake Irene's Milky Way Mirror
Moon, Mars and the Moon's Glitter Path Large and Small
Magellanic Clouds Ancient Tree and Pareidolia The Answer is an
Emirp
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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 6 weeks, 6 days, 14 hours, 54 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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.


Rainbow Closeup on Evia Island, Greece

March 17, 2020

Rainbow 2020-02-21 3

Photographer: Dimitris Malliaris
Summary Authors: Dimitris Malliaris; Jim Foster

I observed this magnificent rainbow in front of Euboean
Olympus, on Evia Island, Greece, just before sunset on February 21,
2020. The way the bow appeared to touch the trees on the hillside in
the foreground immediately caught my attention, so I decided to take a
closeup image. The most vivid rainbow colors result when sunlight is
reflected and refracted through larger raindrops – drops about
0.2 inches (5 mm) or larger in diameter. Surely, there must be a
pot of gold at the end of this fetching bow.

Photo Details: Camera: Canon EOS 6D Mark II; Software: Adobe Photoshop
CC 2015 (Windows); Exposure Time: 0.0050s (1/200); Aperture: ƒ/6.3; ISO
equivalent: 100; Focal Length: 200.0mm; Lens: EF70-200mm f/4L IS USM.
* Pissonas, Greece Coordinates: 38.5236, 23.8585

Related EPODs

Rainbow Closeup on Evia Island, Greece Encore - Sunset Rainbow
Over Samos Island, Greece Sunrise Pillar and Upper Tangent Arc
La Palma Shadow Projection at Sunset Captivating Sunrise from
Portland, Oregon Halo Formation above Cadini di Misurina, Italy
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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

--- up 7 weeks, 6 days, 14 hours, 5 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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.


Big Dipper and the Seasons

June 17, 2020

Composizione 4 stagioni inglese picc (002)

Photographer: Giorgia Hofer
Summary Author: Giorgia Hofer

Featured above are four photos that I took of the Big Dipper in
order to highlight how this familiar asterism of Ursa Major
rotates in the sky during the four seasons. All photos were taken
from locations in Italy in 2019 (summer and fall) and 2020 (winter and
spring), captured between 8:00 p.m. and 10:00 p.m. every 3 months.
Because the stars continue to move overhead all night long (or, more
accurately, Earth continues to spin), the Big Dipper will change
appearance over the course of any given night.

Spring is the season when the Big Dipper is seen highest in the sky --
almost at the zenith and upside down as viewed looking north.
During the summer, the Big Dipper presents itself with its handle
facing upwards. In autumn, the Dipper is closest to the horizon. During
winter, the Big Dipper begins to distance itself from the horizon,
presenting the handle facing downwards.

Photo Details: Nikon D750 camera; Samyang 12 mm fisheye lens; 12 mm
focal length. Spring: from Lorenzago di Cadore, Italy; 10 seconds
exposure; ISO 5000; f/2.8. Summer: from Tre Cime di Lavaredo, Italy; 30
seconds exposure; ISO 1000: f/3.2. Fall: from Piana Mount, Italy; 15
seconds exposure; ISO 6400; f/2.8. Winter: from Misurina, Auronzo di
Cadore, Italy; 4 seconds exposure; ISO 1600; f/2.8.
* Image Coordinates

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Big Dipper and the Seasons The Carbon Star T-Lyrae M51 and
Group Colorful Sirius Lunar Libration Observed from Sicily,
Italy Superluminous Quasar
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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 21 weeks, 16 hours, 4 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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.


Mayan Observatory

July 17, 2020

Fig.1-The Observatory Complex

Fig.2-The Observatory Dome up close

Photographer: Rick Stankiewicz
Summary Author: Rick Stankiewicz
I was unaware until visiting Chichen Itza, that the Mayans
built observatories. It’s thought that a particular building at
Chichen Itza was used for astronomical observations (top photo).
Given its more or less cylindrical shape, like a tiered wedding cake,
it’s referred to as the Observatory. The construction is of cut
stone so there’s no dome for this building, but it wouldn’t be
difficult to imagine one, as the collapsing upper structure gives that
illusion.

Due to the spiral nature of an internal set of stairs that lead to the
upper levels, the Observatory is also referred to as the
Conch/Snail or El Carocol in Spanish. The construction of this
building is thought to be from the Postclassic Period, around
AD 906. No one is allowed to climb around this structure, like most
buildings in the city it’s roped off.

The Mayans were great mathematicians and observers of the sky. They
developed a calendar and marked the changing of the seasons and the
movement of the planets, especially Venus. They were aware of
Venus’ 584-day cycle and that five of these cycles equaled eight
solar years. Venus had tremendous importance for the Maya; this
bright planet was considered the Sun’s twin and a war god. Mayan
leaders used the position of Venus to plan appropriate times for raids
and battles. To further prove their knowledge of celestial motion,
some of their buildings were built to coincide with their physical
observations.

The alignment of at least three upper story windows, or slit-like
openings, of the Observatory, relate to the setting of the Sun
around the equinoxes and also the planet Venus. Of the 29 known
astronomical events that were noteworthy to the Mayans ( equinoxes,
solstices, eclipses, etc.), 20 sightlines for these events are
visible from what’s left of the Observatory today (bottom photo).
Photos taken on April 6, 2011.
* Chichen Itza, Mexico Coordinates: 20.6843, -88.5678

Related EPODs

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History Links

* Paleoclimatology Data
* USGS: Age of the Earth
* What is Geologic Time?
* GSA Geologic Time Scale
* Earth Facts
* Earth History Courses

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

https://epod.usra.edu

--- up 1 day, 15 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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.


The Dolomites World Natural Heritage Area

August 17, 2020

Dolomites Unesco 1

Photographer: Alessandra Masi
Summary Author: Alessandra Masi
The Dolomites of the southern Alps are named after French
naturalist Déodat de Dolomieu who, in the second half of the
eighteenth century, was evidently the first to study the particular
type of rock predominant in this region. The unique mix of minerals
present in these rocks gives the mountains a special light shade, which
is why they’re also called the pale mountains. However, at sunset
and sunrise, the peaks of the Dolomites can be set ablaze by the
rays of the Sun in a spectacle of colors, ranging from pink to
fiery red, This is the effect of the famous enrosadira, or
alpenglow, phenomenon.
The Cortina d'Ampezzo area, a World Heritage Site and under the
protection of the Natural Park of the Ampezzo Dolomites, is a
wonderful setting to discover this special world of immense vertical
rock walls, spires and pinnacles, high mountain pastures, alpine lakes
and beautiful waterfalls. Panoramic photo taken on December 12, 2019.

Photo Details: Camera Canon EOS 5D Mark III; Software Adobe Photoshop
Lightroom 5.7 (Macintosh); Exposure Time 4.000s; Aperture ƒ/14.0; ISO
equivalent 250; Focal Length 24.0mm.
* Cortina d'Ampezzo, Italy Coordinates: 46.540278, 12.136111

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Mount Arenal and Cerro Chato Encore - Holuhraun Fissure Eruption
Encore - Salar de Atacama Edmaier’s Secret Archive - Joshua
Tree National Park
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Geography Links

* Atlapedia Online
* CountryReports
* GPS Visualizer
* Holt Rinehart Winston World Atlas
* Mapping Our World
* Perry-Castañeda Library Map Collection
* Types of Land
* World Mapper

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

https://epod.usra.edu

--- up 4 weeks, 4 days, 15 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)

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 - Observing the Moon on the Same Day from the Northern and
Southern Hemispheres

September 17, 2020

Freitas Moon-Venus-Copenhagen-Mario(3)

Frietas Moon-Venus-Curitiba-SandroColetti (1)

Freitas-Twilight-20h45min-UTC-July-15-2018 (1)

November 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 November 22, 2018.

Photographers: Mario Freitas; Sandro Coletti
Summary Author: Mario Freitas

The shooting times of the pair of photos above differ by less than one
hour, but their locations were more than 10,000 kilometers apart.
During civil twilight on July 15, 2018, the same Moon-Venus
conjunction was observed by amateur astronomers in Copenhagen,
Denmark and Curitiba, Brazil. If we consider that both celestial
bodies lie close to the ecliptic plane, the Earth’s roundness
provides that the arc connecting Venus to the waxing crescent
Moon appears almost horizontal in Copenhagen, but is strongly tilted
upwards in Curitiba.

Fortunately, meteorological conditions were favorable for observing the
sky at both locations -- shooting times were 20:44 for Copenhagen and
21:26 UTC for Curitiba. The simulation by Google Earth makes it
clear that the way the Earth’s axis tilts allows twilight times to
be simultaneous in both cities. Although they differ by 60 degrees in
longitude and 80 degrees in latitude, the geodesic line
between Copenhagen and Curitiba eventually coincides with the solar
terminator. Note that the planet Mercury is also visible in second
picture (at lower left of the Moon).
* Coordinates
+ Curitiba, Brazil: -25.4809, -49.3044
+ Copenhagen, Denmark: 55.676111, 12.568333

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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 3 weeks, 2 days, 20 hours, 20 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)