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.


Similarity Across Scales at the Extreme: Shapes of Pleurosigma and the
Milky Way

January 14, 2020

Pleurosigma 092917 6 rotated copy

Screen Shot 2020-01-03 at 8.56.23 AM

Image of Milky Way: From Optical Gravitational Lensing Experiment
(OGLE) survey and the University of Warsaw
Photo of Pleurosigma: John Stetson
Summary Author: John Stetson

Shown above, at top, is a photo of a sample of micro-life collected
from a plankton tow at Casco Bay in Maine. This Pleurosigma is
about 155 microns in length and has a distinct disk-like shape.
It’s been rotated here (note that Pleurosigma actually do rotate as
they swim through water) to match the orientation of our galaxy,
the Milky Way (bottom photo). This image of the Milky Way was
composed from the Optical Gravitational Lensing Experiment ( OGLE)
survey and the Astronomical Observatory at the University of
Warsaw.

The similarities across scales between the micro-life and Milky Way
is quite interesting. Sir Isaac Newton said the following on the
subject of similarity across scales: "Nature is very similar to
itself...performing all the great movements of celestial bodies with
the help of attraction, gravity...and every small particle motion of
these bodies...with the help of other attractive and repulsive forces
binding particles.” See the Earth Science Picture of the Day for
April 5, 2017 – a comparison between a gravitational lens and a
medusa.
* Casco Bay, Maine Coordinates: 43.6956, -69.9949

Related EPODs

Similarity Across Scales at the Extreme: Shapes of Pleurosigma and
the Milky Way Archive - Visible and Near-Infrared Views of the
Meuse River and Rochers de Néviaux Terrella and the Northern Lights
Solar Power and the Mojave Desert Archive - Infrared
Yellowstone Archive - Weather Balloon
More...

Applied Sciences Links

* BBC: World Water Crisis
* Indoor Air Quality
* Mathematics in Nature
* A Mathematical Nature Walk
* NASA: Applied Earth Sciences
* Remote Sensing Tutorial

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

https://epod.usra.edu

--- up 6 weeks, 3 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.


Love Nest: Build it and She Will Come (maybe)

February 14, 2020

Patti_weaver_DSC02911 2 (002)

Photographer: Patti Weeks
Summary Author: Patti Weeks

The male southern masked-weaver uses his beak to pluck fresh green
blades of grass, palm leaves or reeds and carries them to his nest
site on a tree branch. Then using his beak and feet, he weaves a
pendant-type nest. A female weaver watches the weaving process, and
when the nest reaches an intricate ball-like shape, the male hangs on
the bottom of it, calling and fluttering his wings, is basically asking
her “Will you be my Valentine?” She inspects the nest, but if it
doesn’t live up to her standards, she may tear it down, and the male
has to begin the process again. Or she may simply reject his wooing in
favor of another suitor. When a nest is approved by the female, she
accepts the male’s invitation, and he then completes the building of
their love nest by adding an entrance at the bottom. The female
will line it with feathers, leaves and grass in preparation for laying
2 to 4 eggs. Nest-building for a male weaver is instinctive, but it’s a
skill that takes practice in order to successfully acquire a mate.

Patti_weaver_DSC03686 (002) Endemic to southern Africa, the
southern masked-weaver is one of the more conspicuous birds of the
Ploceidae family (genus Ploceus velatus) During breeding season
the male acquires a black mask and bright yellow breast, head, nape and
underside. It’s speculated that the male’s bright yellow coloring
attracts females. Females are duller greenish-yellow. Males are
polygynous, having multiple partners and will build several nests in a
single season.

I recently had the good fortune to visit South Africa on a photo tour
in the Welgevonden Game Reserve, where we were able to watch a
large, active colony of masked-weavers in a tree full of nests, right
beside our lodge. These love birds are gregarious and often live in
colonies. To our delight, they were constantly chirping, flying to and
from the tree, and building or cleaning out their nests. The top photo
shows a male as he does some housecleaning for one of his nests. To
make it more difficult for predators to enter nests, they’re generally
built at the end of branches, as seen in the second photo -- both
photos taken on December 11, 2019.

Photo Details: Top - SONY DSC-RX10 IV camera; 192.73 mm focal lth; f/4;
1/250 second exposure; ISO 160.
Bottom - Same except 18.21 mm focal lth; f/4.5; 1/1000 sec. exposure;
ISO 100.
* Welgevonden Game Reserve, South Africa Coordinates: -24.3121,
27.8341

Related EPODs

Love Nest: Build it and She Will Come (maybe) Birds on the Move
Crown-of-Thorns Starfish Encore - Spider Webs in Dominican
Amber Archive - Feeding Frenzy Water Droplets on a Spider's Web
on the Viterbo Airport Control Tower
More...

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 3 weeks, 2 days, 15 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.


Encore - Sunset Rainbow Over Samos Island, Greece

March 14, 2020

Ουράνιο τόξο_big

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: Manolis Thravalos
Summary Authors: Manolis Thravalos; Jim Foster

May 2014 Viewer's Choice This gorgeous, high-arching double
rainbow signaled the end to a stormy spring day. It was taken at sunset
from Samos Island, Greece, a small island in the Aegean Sea.
Reddened colors of the primary and secondary bows result from
the increased path length of sunlight when the Sun is below the
horizon. The brightened area of the sky beneath the primary rainbow
occurs when sunlight undergoes a single reflection in raindrops.
Note that despite the brightness of the sky near the horizon, the
camera is facing opposite of the Sun. Photo taken on April 27,
2014.
* Samos Island, Greece Coordinates: 37.7500, 26.8333

Related EPODs

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 Encore - Upper Tangent Arc, Halo, Sundogs
and Glitter Path Observed from Vancouver
More...

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, 3 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.


Archive - Avalanche Pass and Hanging Valley

June 14, 2020

Snowav_1

Each Sunday we present a notable item from our archives. This EPOD was
originally published June 14, 2003.

Provided by: John Cys, Midwestern State University
Summary author: John Cys

The above photo shows a classic avalanche path near Belford Falls,
Colorado. Avalanches repeatedly occur at the same site, and this
results in well defined tracks or paths -- trees do not have sufficient
time for re-growth between avalanche occurrences. The avalanche path
shown here, in the Sawatch Range of the Colorado Rockies, is unusual
because it splits in two near the base of the mountain.

Also shown on the photo (right edge) is Belford Falls, which is at the
end of a hanging valley. Hanging valleys are created at the sides of a
primary glacial valley -- a glacier cuts deeper here than it does in
tributary valleys. When the glacier recedes, the tributary valleys are
left hanging, and this leads to the formation of waterfalls.


Related EPODs

Archive - Avalanche Pass and Hanging Valley Freshwater
Over-layering Saltwater Unusual Snow Crystals The Harding
Icefield Hoarfrost Flowers and Frozen Ripples Methane Bubbles
on Abraham Lake
More...

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 20 weeks, 4 days, 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.


Blossoming of Tajinastes

July 14, 2020

Tajinastes primeros 2020 050

Tajinastes primeros 2020 014

Photographer: Kike Navarro Izquierdo
Summary Author: Kike Navarro Izquierdo

Shown above are the breathtaking blossoms of Tajinastes ( Echium
wildpretii), observed at night on La Palma island, in the Canary
Islands (Spain). The colorful flowers of this unusual plant blossom but
for a short period in the subalpine zone, at elevations between
about 4,200 ft and 6,500 ft (1,280 m and 1,981 m). Once it flowers,
only during late May and early June, it dies. Photos taken on May 20,
2020.

Photo Details: Camera Canon EOS 6D Mark II; Software Adobe Photoshop
CS6 (Windows); Exposure Time 25.000s; Aperture ƒ/2.8; ISO equivalent
6400; Focal Length 15.0mm; Lens Irix 15mm. Bottom - same except:
Exposure Time 30 min; Aperture ƒ/5.6; ISO equivalent 400; illuminated
with flash; circumpolar image because of the long exposure.
* Garafía, Spain Coordinates: 28.7906, -17.9176

Related EPODs

Blossoming of Tajinastes Baboon’s Tail Protandry Phenomenon
in Hollyhock Plants Umbrella Liverwort Frozen Sap of a Yellow
Birch Tree Living Stromatolites
More...

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

--- up 24 weeks, 6 days, 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.


Shelf Cloud over Bonn, Germany

August 14, 2020

SHELFCLOUD

Photographer: Thalia Traianou
Summary Author: Thalia Traianou

This impressive shelf cloud appeared over Bonn, Germany, on the
afternoon of June 17, 2020. An intense thunderstorm ensued with
strong winds, heavy rain and frequent lightning. These
convective clouds, a type of arcus cloud, tend to form along
the leading edge of strong thunderstorms due to the interaction
between the storm’s downdrafts and the very warm, moist air that
feeds the storm. Click here to see a video of this cloud.

Photo Details: OPPO Reno 10x zoom mobile camera; F/1.7; ISO 258; 4.75mm
focal length; in panorama mode.
* Bonn, Germany Coordinates: 50.7374, 7.0982

Related EPODs

Shelf Cloud over Bonn, Germany Red Sprite Lightning Observed
from Attica, Greece Encore - Summer Lightning in Florida
Brasilia Supercell Bolt Out of the Blue Encore - Freezing
Rain and Frozen Globes
More...

Severe Weather Links

* World Severe Weather Information Center
* Enhanced Fujita Scale
* A Lightning Primer
* More About Thunderstorms
* Staying Safe Outdoors in Severe Weather
* NOAA Storm Prediction Center
* Patterns of Lightning Activity
* US National Weather Service

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

https://epod.usra.edu

--- up 4 weeks, 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.


EPOD 20th - Anticrepuscular Rays Observed Over Miami Beach, Florida

September 14, 2020

Sunset_Chatzikyriakidou

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 31, 2019.

Photographer: Kyriaki Antisolar point graphic
Summary Authors: Kyriaki; Jim Foster

The panoramic view above, composed of 4 photos, shows a breathtaking
set of anticrepuscular rays as observed just before sunset at
Miami Beach, Florida, on November 1, 2019. The camera is facing east
northeast. Note the cumulonimbus cloud at the far left. Sunlight
streaming through the turrets of clouds like this, where the Sun is
setting ( opposite of where the camera is facing), may result in
rays that stretch all the way across the sky. However, a small amount
of dust or haze must be present in the atmosphere for the rays
to be seen. Perspective makes them appear to converge in the
distance. The diagram below, courtesy of Dave Lynch, illustrates how
crepuscular and anticrepuscular rays are viewed.
* Miami Beach, Florida Coordinates: 25.7907, -80.1300

Related EPODs

EPOD 20th - Anticrepuscular Rays Observed Over Miami Beach, Florida
EPOD 20th - Shimmer Tree EPOD 20th - Inferior Mirage of a Ship
EPOD 20th - High Altitude Balloon Burst Sunset Observed from
Mount Chasseral, Switzerland Archive - Las Vegas Sunset
More...

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 2 weeks, 6 days, 21 hours, 43 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.


Mass Balance

October 14, 2020

Mass balance

Photographer: Andrea Rapposelli
Summary Authors: Andrea Rapposelli

Essential for a glacier to survive is its mass balance - the
difference between accumulation and ablation ( melting or
sublimation). Climate change can cause large variations in temperature
ranges, both in their averages and in snowfall precipitation as well as
changes in the mass balance. A glacier with a negative balance is not
in equilibrium and will tend to retreat. A glacier with a positive
balance is also in a state of imbalance but will advance to restore it.
The retreat of the glacier manifests itself in the loss of its lower
region which because it’s at a lower altitude is normally warmer than
the higher zones. Glacier melting reduces overall ablation, thus
increasing mass balance and potentially restoring equilibrium. If the
mass balance of a significant part of the glacier accumulation zone
is negative, it's out of balance with the climate and will tend to melt
if a colder climate and/or an increase in solid precipitation does not
occur. The photograph above of the Montabel glacier was taken near the
town of Breuil-Cervinia. The central rocky tip was covered by snow a
few decades ago. Photo taken July 22, 2020.

Photo Details: Camera PENTAX K-5; telephoto lens 18-55 mm at 55mm;
Software Adobe Photoshop CC 2015 (Windows); Exposure Time 0.010s
(1/100); Aperture ƒ/9.0; ISO equivalent 400; Focal Length (35mm) 82.
* Breuil-Cervinia, Italy Coordinates: 45.934444, 7.631111

Related EPODs

Mass Balance Archive - Longest Day Ice Out on Sebago Lake
in 2020 Archive - Breidamerkurjökull Ice Cap Death Valley’s
Zabriskie Point Dust and Isla de La Palma, Canary Islands

Climatology Links

* Aerosols: Tiny Particles, Big Impact
* JetStream - An Online School for Weather
* Climate History
* National Centers for Environmental Information
* Global Climate Animations
* NOAA Climate Analysis Branch
* Vital Climate Graphics

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

https://epod.usra.edu

--- up 7 weeks, 1 day, 20 hours, 21 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)