EPOD - a service of USRA

EPOD 20th - Foggy Start to the Day in Budapest, Hungary

2020-09-02T03:01:00-04:00

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 June 01, 2013.

Photographer: Miklos Mayer
Summary Author: Miklos Mayer

This photo shows the capital of Hungary, Budapest, under a blanket of fog on a cold, winter morning. Only a 666 ft (203 m) high chimney is able to peer through the thick fog. This is an example of valley fog or radiation fog that often forms in low-lying areas on cold clear nights, especially in fall and winter. During the nighttime hours as the surface cools, if the dew point is reached, fog will hug the ground, with a layer of warmer air above -- an inversion layer. In most cases, the foggy mantle is relatively shallow (tens of feet), but on occasion, it'll extend several hundred feet above the surface. Because this phenomenon was forecast, I positioned myself high above Budapest on Harmahatar Hill (1,575 ft or 480 m high) a little before daybreak in order to capture this scene. The atmosphere above the inversion layer was quite clear, thus the Matra Mountains, some 50 mi (80 km) distant, could be seen on the eastern horizon. Photo taken on January 17, 2011.

Photo Details: Camera: Canon EOS 1000D; Lens: EF28-105mm f/3.5-4.5 USM; Focal Length: 55.0mm; Aperture: f/1.8; Exposure Time: 0.033 s (1/30); ISO equiv: 100; Software: Adobe Photoshop Lightroom 3.4.1.

[8/20]

EPOD 20th - Driftwood at La Push, Washington

2020-09-01T03:01:00-04:00

Photographer: Phillip Lachman
Summary Author: Phillip Lachman

This piece of driftwood washed up on the beach at La Push, a small community in Clallam County, Washington. On our visit there in early spring, a very strong gale was blowing. Powerful winds accompanied by high tides are required to bring monsters like this ashore. The entire length of the beach was strewn with driftwood of all sizes. La Push, surrounded by the lush forest of the Olympic National Park, is located on the northwest coast of Washington's most westerly peninsula, at the mouth of the Quillayute River. La Push is the home of the Quileute Tribe. Picture taken April 5, 2010.

Photo Details: Camera: FUJIFILM FinePix S7000; Focal Length: 22.0mm; Aperture: f/5.0; Exposure Time: 0.0031 s (1/320); ISO equiv: 160.

[8/20]06152010

Sunset Observed from Mount Chasseral, Switzerland

2020-08-31T03:01:00-04:00

Photographer: Arnaud Besancon
Summary Author: Arnaud Besancon

Shown above is a captivating sunset scene I observed earlier this summer from Mount Chasseral, Switzerland (5,269 ft or 1,606 m). The camera is facing southeast. Lake Neuchâtel is at lower right. The ambiance created by the interplay of clouds, shadows and fading light was fantastic. At the top, the triangular shadow of Mount Chasseral can be seen cast upon the cloud deck. Note the rainbow fragment at the lower right-center. Photo taken on July 1, 2020.

Photo Details: 5D3 camera; 135 mm; F11; ISO 100; 1/15 second exposure time.

Archive - Las Vegas Sunset

2020-08-30T03:01:00-04:00

Each Sunday we present a notable item from our archives. This EPOD was originally published August 30, 2003.

Provided by: Carl Crumley
Summary author: Carl Crumley

The low humidity of the desert in the vicinity of Las Vegas, especially during the dry summer months, results in few clouds, and if airborne aerosols such as dust aren't present when the Sun is near the horizon, colorful sunsets aren't often observed. However, as seen above, on August 5, 2003, a cirrus cloud deck in the western sky resulted in this striking sunset.

Related Links:

[8/20]

Encore - Altair and Barnard's "E"

2020-08-29T03:01:00-04:00

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

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.

[8/20]10182014

Cotton Trees

2020-08-28T03:01:00-04:00

Photographer: Menashe Davidson
Summary Author: Menashe Davidson

As shown above, it’s easy to understand why this tree is called the cotton tree. Its scientific name is Bombax malabaricum, though it’s also referred to as the red silk cotton tree or Kapok tree. Its fruits (pods) are brown oval capsules that when ripe contain seeds and white cotton-like fibers, a mix of lignin and cellulose. Cotton trees produce several hundred of these 6 inch (15 cm) pods.

These photos were taken in a park in Rishon LeZion, Israel, where the cotton tree is grown as an ornamental. When leafless, in February, its scented flowers are particularly fragrant. In India, villagers gather the fruit and extract the cotton-like substance for filling pillows, sofas, etc. Photos taken May 29, 2020.

The Sun’s Green Rim Observed from Arroyo de San Serván, Spain

2020-08-27T03:01:00-04:00

Photographer: Juan Manuel Pérez Rayego
Summary Authors: Juan Manuel Pérez Rayego; Jim Foster

The photo above showing the green rim of the Sun’s trailing rim was captured at sunset from Arroyo de San Serván, Spain. As the Sun sets, if atmospheric conditions are favorable (relatively clear and not optically thick), there’s a chance you might detect an emerald-colored lining on the Sun’s upper rim. This occurs because when the Sun is near the horizon the atmosphere can behave like a prism and as a result sunlight is separated into different colors. However, the green rim is best seen when the Sun is actually a degree or two above the horizon. Note that the wind turbine silhouetted against the Sun’s disk is in Portalegre, Portugal, about 57 miles (92 km) away from my location. Always use caution when looking toward the Sun. Photo taken on June 14, 2020.

Photo Details: DSLR (x1.6) + 400 mm; f / 5.6; 1/1250 sec. exposure; ISO 100.

Reynisfjara Beach, Iceland

2020-08-26T03:01:00-04:00

Photographer: Salvatore Cerruto
Summary Author: Salvatore Cerruto

One of the many geological wonders on the island of Iceland is the black sand of Reynisfjara beach, on a volcanic bay in the south of Iceland. This beach is often on lists of the most beautiful beaches of the world. The sand here is derived from weathered basalt.

Basalt columns, best seen at upper right, form as iron and magnesium-rich basalt lava cools and contracts. Once exposed to the surface air it hardens and solidifies. Generally, the fracture pattern begins at the cooler surface and is propagated downward as the cooling process spreads, forming long, geometric — and usually hexagonally shaped — columns of rock. To me, this rock formation resembles a fallen dragon, one of the majestic beasts sometimes associated with fantasy films on exotic islands like Iceland. Photo taken on September 25, 2017.

Color in Opals

2020-08-25T03:01:00-04:00

Photographer: Mila Zinkova
Summary Author: Mila Zinkova

The most valuable opals, referred to as precious opals, display play of color, patches of spectral colors that occur when this gemstone is tilted. Both frames of the image above show the same Ethiopian opal from Mezezo, and both frames also depict the same part of the opal. The dark patches in the left frame became bright green/blue when I found the proper angle to display the color. These patches are called digits. Making them exhibit colors is simply a matter of working to find the right angle. In some opals, digits create an elaborate color network, as it is seen in the second opal featured in this video. However, only rarely will color appear in multiple digits from different clusters at the same time.

Lavender

2020-08-24T03:01:00-04:00

Photographer: Fabio Di Stefano
Summary Author: Fabio Di Stefano

In the months of June and July in Tuscany (Italy) it’s possible to see a spectacular landscape the color of lavender and violet. Fields of lavender in bloom stretch for miles, a visual and also an aromatic delight. In years past, many of these fields were cultivated in wheat but in recent years they’ve been converted to lavender. A number of farmers in this region are now active beekeepers, producing both lavender flavored honey and scented beeswax (candles). Photo taken on June 20, 2020.

Photo Details: Top - Camera Canon EOS M6; Software Adobe Photoshop Lightroom Classic 9.3 (Windows); Exposure 0.013s (1/80); Aperture ƒ/8.0; ISO 500; Focal Length 50.0mm; Bottom - same except: Exposure 0.0050s (1/200); Aperture ƒ/4.5; ISO 100.