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.


Star Trails and Moiré Patterns in Night-Sky Photography

January 30, 2020

Star Trails On Desert

Photographer: Nima Asadzadeh
Summary Author: Nima Asadzadeh

The star trails shown above were viewed over the Maranjab Desert in
Iran. You may be able to notice that some of the star trails,
particularly at the center of the image, form rather unusual
symmetrical patterns. These patterns result from an optical phenomenon
that’s called the moiré effect. Whenever we observe repetitive
shapes, the light rays that reach our eyes are interfered with in such
a way to form rather symmetrical patterns. This seems to be the case no
matter the detector, human eyes, CCD cameras, etc. To avoid seeing
these shapes, better resolution is needed to separate out all the tiny
sections of the whole image so other paths are available for the light
rays to reach our eyes without interference. For instance, looking
through the holes of mesh fencing from up close rather than from a
dozen feet away.

In this image, the interval between consecutive shots is about 1 second
more than the appropriate shutter speed for an 18 mm focal length.
This extra second causes a gap between each of the shots required to
make the image and the repetitive trails of the stars, causing the
moiré patterns to appear. A zoom-viewed image is used to compare
with the full-size image. Note that the brightest star trail is that of
the brightest star in the sky, Sirius. Image taken on December 14,
2019.
* Maranjab Desert, Iran Coordinates: 34.1832, 51.1332

Related EPODs

Star Trails and Moiré Patterns in Night-Sky Photography Slender
Moon Over Modica, Italy Quadrantid Meteor Shower Encore - Lake
Irene's Milky Way Mirror Moon, Mars and the Moon's Glitter Path
Large and Small Magellanic Clouds
More...

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 1 week, 1 day, 15 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.


Saturn, Jupiter, the Moon and Mars Alignment and the ISS

March 30, 2020

Saturn Jupiter Moon Mars Alignment and ISS Passage 19 February 2020
Label EPOD

Photographer: Dario Giannobile
Summary Authors: Dario Giannobile; Jim Foster

Just before daybreak on the morning of February 19, 2020, it was
possible to witness a very fascinating celestial show. Near the end of
the astronomical night I observed Saturn, Jupiter, Mars and
the Moon, all rising over this marine coast on the island of Sicily
(Italy). Note that the ashen, waning moon is accented by a
corona.

The International Space Station passed over almost exactly when the
ambient light was changing. This is why this image shows the
transition from night to dawn by means of multiple shots, allowing me
to track the ISS across the sky. This crossing lasted 4 minutes, during
which time the light changed considerably.

Early tomorrow morning, before dawn, Mars passes just south (0.9
degrees) of Saturn, and Jupiter is just 6.3 degrees west of this bright
duo. If you’re up early, make sure to take a look.
* Syracuse, Italy Coordinates: 37.0755, 15.2866

Related EPODs

Saturn, Jupiter, the Moon and Mars Alignment and the ISS
Betelgeuse at its Minimum Brightness Encore - Geminid Meteors
Observed Over Leiria, Portugal Star Trails and Moiré Patterns in
Night-Sky Photography Slender Moon Over Modica, Italy
Quadrantid Meteor Shower
More...

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 9 weeks, 5 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.


Lava Tube on La Palma

June 30, 2020

T3 Cueva Palomas

Photographer: Antonio Gonzalez
Summary Author: Antonio Gonzalez

This panoramic composition shows an immersive 360-degree image of a
volcanic cave, or lava tube, on La Palma island in the
Canary Islands of Spain. The Canaries, like the Hawaii islands,
were born as a result of volcanic activity.
In 1949, the San Juan volcano expelled lava that passed through
the area where the cave is now. The upper part of the lava flow was in
contact with the air and cooled very quickly; while in the lower part
of the flow, where the panorama was made, lava continued to circulate
well after the upper part cooled. As the lava level came down, it
eventually formed this cave – a hollowed out river of hardened lava
approximately 1800 ft (549 m) in length. It’s open to the public and
very easy to walk through. Note that the formation of lava caves is
very different than caves that form in a karst topography

This panoramic picture was made with a group of 3 immersive 360-degree
photographs on June 27, 2015. Click here to see similar photos.
Thanks to the Innovation área of Cabildo La Palma and to Eduardo Diaz y
Paco Govantes for their help.
* La Palma, Spain Coordinates: 28.601276, -17.890769

Related EPODs

Lava Tube on La Palma Archive - Geological Unconformity
Young Lava and Old Olivine A Crack in the Moon? Mount Etna
and Pillow Lava of Aci Castello Archive - Blended Image of Rock
Outcrop
More...

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

--- up 22 weeks, 6 days, 16 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.


Cirrus Rows

July 30, 2020

D4D7C491-1A91-4312-9860-93DD77F3F022

Photographer: Sally Budack
Summary Authors: Sally Budack; Jim Foster
Driving near my home in Tacoma, Washington, several weeks ago I noticed
a curious cloud formation with oddly regular stripes. I pulled over to
take the picture shown above. These clouds dissipated quite quickly.
They appear to be a type of cirrus cloud ( cirrus fibratus) that
tends to become oriented in the direction of the upper air flow,
resulting in parallel rows -- like window blinds to the upper
atmosphere. Photo taken on June 11, 2020.

Photo Details: Camera - Apple iPhone 6s; Exposure Time - 0.0001s
(1/8547); Aperture - ƒ/2.2; ISO equivalent - 25; Focal Length (35mm) -
146.
* Tacoma, Washington Coordinates: 47.2529, -122.4443

Related EPODs

Cirrus Rows Building Storm Near Belo Horizonte Brazil Trade
Winds and Clouds on La Palma Santa Ana Wave Clouds Sierra Wave
Glaciated Clouds Over Paris
More...

Cloud Links

* Atmospheric Optics
* The Cloud Appreciation Society
* Cloud Atlas
* Color and Light in Nature

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

https://epod.usra.edu

--- up 2 weeks, 15 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (21:1/186)