Earth Science Picture of the Day

Captive Geyser of Soda Springs, Idaho

2012-06-04T03:01:00-04:00

Photographer: Ray Boren
Summary Author: Ray Boren

Every hour on the hour, every day of the year, a powerful geyser erupts in the middle of the southern Idaho community of Soda Springs. Technically, artificial geysers are known as erupting geothermal wells. This one is named Captive Geyser, perhaps the only man-made and top-of-the-hour timed geyser in the world. When it erupts, droplets spray for yards around (watch out for your cars, glasses and camera lenses), helping build the orange-red mineral dome that circles the geyser. When the geyser is quiescent, the wet dome-top is peaceful and cool enough that flocks of birds, such as pigeons, land on it to check out the possibilities.

Historical signs tell the tale of how this man-made geyser came to be. Three-quarters of a century ago Soda Springs entrepreneurs, hoping to entice tourists, sought "to find and divert hot water from nearby Pyramid Spring to develop a commercial bathhouse and health resort. On November 28, 1937 at a depth of 315 ft (96 m), their hopes and dreams seemed within reach. The drilling rig pierced a gas chamber and... hot water began gushing upward more than 40 ft (12 m)" into the air. "The next day, after the 3,500-pound (1,588 kg) bit was removed, the ground shook as if it were about to split open and a roaring geyser of more than 70 ft (20 m) streamed upward from the valve. After several days, the hissing hot water began to cool and become laden with mineral content (hard water), rendering it undesirable for use as a bathhouse. Two weeks later, the drilling riggers were able to finally cap the gusher” now known as Captive Geyser. If your back is to the Sun, rainbows accompany the geyser during the early to midmorning hours and midafternoon to early evening hours. Photo taken on September 10, 2011.

Photo details: Top - Camera Maker: NIKON CORPORATION; Camera Model: NIKON D60; Focal Length: 32.0mm; Aperture: f/8.0; Exposure Time: 0.0020 s (1/500); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Flash Fired: No; Orientation: Normal; Color Space: sRGB; Software: QuickTime 7.6.4.

Daniel Boone National Forest

2012-06-03T03:01:00-04:00

Photographer: Ross Wehner; Ross' Web site
Summary Author: Ross Wehner

The photo above was taken from the Red River Gorge in southeastern Kentucky, just inside the Daniel Boone National Forest. I was hiking up Double Arch Trail on this early spring day and noticed that part of the trail had been washed out by a recent deluge. The red rock and soil here likely derive their flaming colors from iron oxides. Geologically, the Red River Gorge is part of the Pottsville Escarpment. Note that the trees, several of which are chestnut oak (Quercus prinus) had just begun to leaf out. They contrasted beautifully with the red soil formations and Columbian blue sky. Photo taken on April 6, 2012.

Photo details: Camera Maker: PENTAX; Camera Model: PENTAX K-x; Lens: smc PENTAX-DA 18-250mm F3.5-6.3 ED AL [IF]; Focal Length: 18mm (35mm equivalent: 27mm); Aperture: f/8.0; Exposure Time: 0.0031 s (1/320); ISO equiv: 400; Exposure Bias: +0.30 EV; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); Exposure Mode: Auto Bracketing; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Aperture 3.2.3.

Double Rainbow Panorama Over Amersfoort, The Netherlands

2012-06-02T03:01:00-04:00

Photographer: Jurgen de Boer; Jurgen's Web site
Summary Author: Jurgen de Boer; Jim Foster

This double rainbow panorama was captured over Amersfoort, the Netherlands following a hail-producing afternoon thunderstorm. Clearly visible here are the primary and secondary rainbows, Alexander's dark band (the darkened area between the two bows) and supernumerary bows just beneath the top of the primary bow. Whereas refraction and reflection of light in raindrops explains how the primary and secondary bows are formed, the wave nature of light is needed to understand how light interacts with the tiny, nearly same-sized droplets that are responsible for the formation of supernumerary bows. Panorama taken on May 16, 2012.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 60D; Lens: EF28-70mm f/2.8L USM; Focal Length: 28mm; Aperture: f/8.0; Exposure Time: 0.0031 s (1/320); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Exposure: program (Auto); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop CS5 Windows.

Intense Spring Aurora Over Northern Michigan

2012-06-01T03:01:00-04:00

Photographer: Greg Raniszewski; Greg's Web site
Summary Author: Greg Raniszewski; Jim Foster

The photo above shows the northern lights as viewed from Sleeping Bear Dunes National Lakeshore in Michigan on the night of April 23, 2012. Not only was there a remarkable aurora display, but the Moon was below the horizon and so didn't steal any luster away from the show. Green color dominated early on but later in the night both green and red aurora saturated the northern sky. In late spring and summer, the only place where aurora can be easily seen is in the mid-latitudes -- the sky isn't dark enough to observe them further to the north (or to the south in the Southern Hemisphere).

Photo details: Camera Maker: NIKON CORPORATION; Camera Model: NIKON D90; Focal Length: 24.0mm (35mm equivalent: 36mm); Aperture: f/2.8; Exposure Time: 30.000 s; ISO equiv: 400; Exposure Bias: none; Metering Mode: Matrix; Exposure: Manual; Exposure Mode: Manual; White Balance: Manual; Light Source: Cloudy; Flash Fired: No; Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop Elements 10.0 Windows.

Temples of the Angkor Complex in Cambodia

2012-05-31T03:01:00-04:00

Photographer: Sue Strickland
Summary Author: Sue Strickland

The temples of the Angkor complex, near the Cambodian city of Siem Reap, were abandoned and left to decay for nearly 500 years after the fall of the Khmer empire in the 15th century. The indigenous jungle plants of Cambodia quickly began to invade and destroy the structures. When efforts to conserve and restore the temples of Angkor began in the early 20th century, archeologists decided to leave one temple, Ta Prohm, largely as it had been found except for clearing a path for visitors and strengthening the buildings to prevent further deterioration. The spung trees (Tetrameles nudiflora) growing out of the ruins and the dense jungle surroundings make it possible for visitors today to experience Ta Prohm very much as the early explorers did when they first came upon the temples of Angkor, in the middle of the 19th century.

Ta Prohm is one of the largest and most picturesque temples in the Angkor complex. Constructed as a Buddhist monastery, from the mid-12th to early 13th century, the temple was home to more than 12,500 people (including high priests, officials, assistants and dancers), all of whom were supported by a population of nearly 80,000 people who worked in nearby villages to provide food and supplies. Ta Prohm was also the headquarters of a vast hospital network, providing supplies for over 100 hospitals located throughout the Khmer empire.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS DIGITAL REBEL XTi; Focal Length: 17.0mm; Aperture: f/8.0; Exposure Time: 0.020 s (1/50); ISO equiv: 400; Exposure Bias: -0.33 EV; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: Adobe RGB (1998); Software: Adobe Photoshop Elements 8.0 Windows.

Hudson River Palisade Rockslide

2012-05-30T03:01:00-04:00

Photographer: Michael J Passow; Michael's rockslide photos web page
Summary Author: Michael J Passow

I noticed this impressive rockslide while kayaking near the Palisades of the Hudson River on May 19, 2012. A huge slab of the Triassic intrusion of the Palisade diabase (also known as tap rock) broke off these prominent cliffs (over 300 ft or 90 m high in places) several days before this picture was snapped. The largest blocks are over 10 ft (3 m) long. Chunks of river mud were thrown up as the slide entered the Hudson River. This mud contains small shells and is an excellent example of how fossiliferous shale might have formed.

Photo details: Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: uT6000,ST6000; Focal Length: 5mm (35mm equivalent: 28mm); Aperture: f/5.0; Exposure Time: 0.0031 s (1/320); ISO equiv: 50; Exposure Bias: none; Metering Mode: Matrix; Exposure: program (Auto); White Balance: Auto; Flash Fired: No (enforced); Color Space: sRGB.

22 Degree Halo and 46 Degree Halo

2012-05-29T03:01:00-04:00

Photographer: Lisa Gonnelli
Summary Author Lisa Gonnelli; Jim Foster

The photo above showing a 22 degree halo and what may be a 46 degree halo (faint arc at top) was taken from Pilesgrove, New Jersey on March 10, 2012. Whereas the frequently observed 22 degree halo is formed by the minimum deviation of refracted sunlight through 60 degree prisms (hexagonal ice crystals); 46 degree halos result from minimum deviation through 90 degree prisms. Both halos are formed in the same poorly aligned ice crystals, but because a smaller amount of light emerges through the 90 degree prism and since the 46 degree halo is more readily dispersed (spread out across the sky), it’s considerably dimmer than the smaller 22 degree halo. 46 degree halos are quite rare and can be easily confused with more colorful supralateral or infralateral arcs. Always protect your eyes when looking for these halos, particularly the 22 degree halo.

Photo details: Camera Maker: OLYMPUS IMAGING CORP.; Camera Model: E-500; Focal Length: 17.0mm; Aperture: f/9.0; Exposure Time: 0.0050 s (1/200); ISO equiv: 100; Exposure Bias: -0.70 EV; Metering Mode: Matrix; Exposure: Creative Program (based towards depth of field); Exposure Mode: Manual; White Balance: Manual; Light Source: Cloudy; Flash Fired: No (Auto); Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop Elements 8.0 Macintosh.

Whirlpool Galaxy

2012-05-28T03:01:00-04:00

Photographer: John Chumack; John's Web site
Summary Author: John Chumack

Shown above are two colliding galaxies in the direction of the Canes Venatici constellation, only a few degrees from the end star in the handle of the Big Dipper. The featured galaxy is the classic spiral of M51, the Whirlpool Galaxy, also known as NGC-5194. In this image, M51 is interacting with the dwarf galaxy NGC-5195 to the left. The pair is approximately 23 million light years away from our Milky Way Galaxy.

I processed this image to highlight the tidal (gravitational) structures in the tail of M51 and its companion. Note the crimson colored dust lanes swirling toward the center of M51 as well as the faint background galaxies behind and below the tidal tail. This is a 17.5 hour exposure acquired during seven separate nights in early 2010 and early 2011. All data were taken with my homemade 16 inch, F4.5, fork mounted Newtonian telescope, at John Bryan State Park in Yellow Springs, Ohio.

Image details: Captured with my QHY8 Cooled color CCD camera and my modified Canon Rebel Xsi DSLR camera, data from both cameras were used -- both employed a Celestron Coma Corrector and Astronomiks CLS filter. Both camera data sets were combined and resized to match in Maxim DL; initial color balanced performed in Nebulosity; Gradient XT to remove light pollution gradients; Adobe PS was used for Luminance Layering and final color balance. Luminance Data (QHY8) 4 hours (240 minutes) Hydrogen Alpha Data (QHY8) 3.5 hours (210 minutes) RGB Data = modified "Baader" Canon Rebel Xsi 10 hours (600 minutes); 210 sub frames captured -- total 17.5 hours or 1,050 minutes of exposure.

Corrosion on Building Facade

2012-05-27T03:01:00-04:00

Photographer: Glenn Woodell; Glenn's Web site
Summary Author: Glenn Woodell

This example of environmental wear on anodized aluminum demonstrates the electrochemical nature of corrosion. Moisture in the air or from rain combined with the molecules in the metal, or in the moisture source, forms an electrochemical cell, complete with an anode and a cathode. The anodic region is where the corrosion is centered, while the cathodic region is the oppositely charged area surrounding the anode. The radius of this charge is what actually protects, to an extent, the surrounding area from further corrosion. This causes the surface of the aluminum to have what appears to be regularly spaced corrosion. (See black & white detail.) However, rather than being regularly spaced, there's a minimum distance below which further corrosion is not being allowed to initiate. The aluminum shown above is part of the decorative facade on the front of a 50-year old building. This area was never in direct sunlight. Areas receiving direct sunlight at least part of the time had much less corrosion. Photo taken on May 3, 2012.

Photo details: Camera Maker: SAMSUNG; Camera Model: SGH-i937; Focal Length: 4.03mm; Aperture: f/2.6; Exposure Time: 0.0058 s (1/172); ISO equiv: 6400; Exposure Bias: none; Metering Mode: Center Weight; Exposure: aperture priority (semi-auto); White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop CS5.1 Windows.

Occultation of Zeta Tauri

2012-05-26T03:01:00-04:00

Photographer: Mohamed Laaifat
Summary Author: Mohamed Laaifat; Jim Foster

The photo sequence above shows the waxing crescent Moon occulting the star Zeta Tauri. It was taken from Normandy, France on April 25, 2012, at about 10:30 p.m. local time. This modest, third-magnitude star in the constellation of Taurus the Bull was occulted from our perspective here on Earth by the non-illuminated portion of the Moon. Because glare is minimal with an occultation such as this, an observer can more easily view the event and time the star’s disappearance and reappearance. Note that Zeta Tauri appears the same when in contact with the lunar limb as it does in the other frames. If the Moon had an atmosphere, a slight difference in brightness could be detected.

Photo details: Nikon D60 camera; ETX 7O mm.