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.


Opalized Fossil of a Cycad Cone

January 06, 2023


Mila_cycad (003)

Photographer: Mila Zinkova

Summary Author: Mila Zinkova

Shown above is an opalized cycad cone fossil (31 x 11 x 9 mm) that
was found in Lighting Ridge, Australia. Fossil cycads, dating from the
Mesozoic, have been uncovered on every continent. These very
ancient group of seed plants are thought to be a sister group to all
other living seed plants.

Most fossil cycads are called cycadeoids and are classified
scientifically in the order Bennettitales. During the Jurassic,
cycads and their kin, along with conifers and ginkgos, dominated
the plant kingdom. They remain extant and are commonly referred to
as living fossils.

On occasion, cycad fossils are opalized. If a cavity in a rocky
surface resulted when a living organism, such as a shell or pinecone,
was buried in sand or clay and then rotted away, an opalized cast or
fossil replica may form of the object that was buried. Click here
to see a video of this fossil, which also includes clips of a modern
cycad.


Lighting Ridge, Australia Coordinates: -29.4278, 147.9790


Related EPODs

Opalized Fossil of a Cycad Cone Radial Stress Fracture Red
Bar Natural Bridge, Utah Crystal Forms in Petrified Wood Mt.
Baker at Sunrise Fossil Find in Sicily, Italy
More...

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 44 weeks, 4 days, 20 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.


Six Years of Full Moons

February 06, 2023


滿月顏色37危海排列1.8M

Photographer: Meiying Lee

Summary Author: Meiying Lee
This composite shows the full moons I’ve captured over the past 6+
years from my home in Taiwan. Because Mare Crisium is located on
the east side of the moon, its position can be used as a guide to the
moon’s location in the sky. Therefore, the moons pictured here are
arranged according to where the moon was in the sky on the night it was
photographed.

On the top row, Mare Crisium is the circular crater at the top of the
lunar disk. When it's in this position, the full moon rises in the
east. As the moon rises, the position of Mare Crisium shifts to the
right. When Mare Crisium is on the right side of the lunar surface, the
full moon is near the zenith –- around midnight. At this time of night,
the sky is near its darkest, and if the weather is clear, it’s easier
to detect the iron-gray lunar surface.

As the moon sets, Mare Crisium is turned toward the lower right. A full
moon sets about the time that the Sun rises. The color of the dawn is
usually gray-blue or pink-gray, so the color of the full moon will be
close to the color of the sky, and details in the lunar surface are
more challenging to detect.

All photos were taken at the same focal length. But you can observe
that the size of the moon may change significantly from one shot to the
next. This is of course related to the distance between the moon and
the Earth. Note that I also captured phases of a total lunar
eclipse (rows 2 and 3) as well as a jet airliner (row 3) passing
overhead of my location.

Yunlin, Taiwan Coordinates: 23.7092, 120.4313


Related EPODs

Six Years of Full Moons Backyard Viewing of Saturn and Uranus
Total Lunar Eclipse and over Quebec City Milky Way and Summer
Triangle Mars, Auriga and Taurus Lunar Occultation of Uranus
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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 49 weeks, 21 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.


Giant Bialy

March 06, 2023

20210710_132845

20230105_093118

Photographer: Roger Hopkins
Summary Author: Roger Hopkins
Our waterfall produces a full menu of foam goodies, including
marshmallows, pancakes, donuts, bagels, and recently, a spectacular
bialy. This foam, frequently misunderstood to be man-made
pollution, is a natural phenomenon in our case. Decaying plant material
is mixed in the turbulence of the stream, acting as a surfactant to
reduce the surface tension of the water and allowing the formation
of persistent small "soap" bubbles in the turbulence. We normally see
these after a period of rain with more organic material leaching into
the stream.
The waterfall has this nice gentle eddy at the base that forms
these round shapes. The brown streaks are probably caused by tannin
washed into the stream from decaying oak leaves and branches upstream.
Click here to see a video of this foam forming. Photo taken on
January 5, 2023.

Asbury, New York: 42.526283332981414, -76.48522451537521

Related EPODs

Giant Bialy Wallaman Falls, Australia Water Eruption
Flood Hazard in the Desert Skypools on Surface Waves Great
Salt Lake’s Mirabilite Mounds
More...

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 1 year, 1 week, 20 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)