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Venus

Venus in Color

The bluish hue of Venus is an effect of the colorization technique used to enhance subtle contrasts in cloud patterns and indicates that this image was taken through a violet filter. Features in the sulfuric acid clouds near the top of the planet's atmosphere are most prominent in violet and ultraviolet light. This image shows the east to west cloud banding and the brighter polar hoods . The features are embedded in winds that flow from east to west at about 370 kph (230 mph).

Impact Craters

Three large impact craters with diameters ranging from 37 km (23 mi) to 65 km (40 mi) are visible in the fractured plains. Features typical of meteorite impact craters are also visible. Rough radar-bright ejecta surrounds the perimeter of the craters; terraced inner walls and large central peaks can be seen. Crater floors appear dark because they are smooth and have been flooded by lava. Domes of probable volcanic origin can be seen in the southeastern corner. The domes range in diameter from 1-12 km (0.6-7 mi); some have central pits typical of volcanic shields or cones.

Bright Plains

Located along the left central edge of the image is a cluster of volcanic domes that ranges from 1.5 km (1 mi) to 7.5 km in diameter (5 mi). The domes and their deposits are located at the convergence of radar-bright lineaments that are interpreted to be faults and troughs. In some places the domes overlie the faults. The faults and troughs extend into the lower parts of the image where they terminate against dark plains deposits and are crosscut at right angles by additional faults. The relationship between these features indicates that multiple episodes of faulting and volcanism have occurred.

Ovda Regio

The tectonic fabric of this region of Ovda Regio trends predominantly east-west. The large radar-dark areas are probably tectonically formed basins that have been filled in by fluid lava flows, thus presenting a smooth surface to the Magellan radar system.

Ridges and Troughs

On this bright, lineated terrain Alpha Regio is a series of troughs, ridges, and faults running in every direction. The lengths of these features range from 10 km (6.3 mi) to 60 km (37 mi). The elevation of Alpha Regio varies over a range of 4 km (2.5 mi). Low-lying areas appear dark in the radar images and may be filled with lava. Volcanoes appear as bright spots on the smooth plains. Notice the large volcano in the upper right. At the center of this 35 km (22 mi) volcano is a caldera; its western edge appears to be either a debris flow or a lava flow. The black square represents missing data.

Highlands

Several tectonic events formed this complex terrain, which is part of the interior of Ovda Regio. An underlying fabric of ridges and valleys lies NE-SW. These ridges are spaced 10-20 km (6-12 mi) apart and may have been caused by compression of the crust at right angles to the ridge. The ridges are cut by bright features extending NW-SE. The largest valleys, particularly the 20 km (12 mi) wide valley extending across the image, were filled with dark material, probably lava. The complexity of Ovda Regio attests to a long history of tectonic deformation.

Eastern Lakshmi

Lava flows blanket the flat plains region of eastern Lakshmi. The dark flows most likely represent smooth flows similar to pahoehoe flows on Earth, while the brighter areas are rougher flows resembling Earth's aa flows. Three dark splotches mark the tops of these lava flows. Because of the thick atmosphere surrounding Venus, small impactors break up before they hit the surface. The fragments are deposited over the surface and produce the dark splotches seen here. Notice the splotch on the far right has a crater at its center, indicating that the impactor was not completely destroyed.

Lava flows

This mosaic highlights a system of east-trending, radar-bright and dark lava flows that collide with and breach a north-trending ridge belt (left of center). Upon breaching the ridge belt, the lava pooled, forming a radar-bright deposit approximately 100,000 square km (right side of image). The source of the lava is the Corona Derceto, which lies about 300 km (186 mi) west of the scene. The bright and dark bars extending from top to bottom are artifacts of image processing.

Coronas in Fortuna

Two large oval features can be seen in this image of Fortuna. On the left is Ba'het Patera, 230 km (138 mi) long and 150 km (90 mi) across. A portion of Onatah Corona, over 350 km (210 mi) in diameter, is visible on the right. Both features are surrounded by a ring of ridges and troughs. The central areas of the coronae contain radial fractures as well as volcanic domes and flows. Coronae may form due to the upwelling of hot material from deep in the interior of Venus. These two coronae may have formed at the same time over a single upwelling. The black strip represents missing data.

Lavinia Region

The bright area running from the upper right to the lower left may be part of a belt of ridges formed by compression and thickening of the upper layers of the planet. The area between the ridges suggests flooding by lava flows. The varied textures of the lava can be seen in the mottled appearance of the plains, which have been cut by the ridges; brighter, rougher flows are also quite common. The lighter area in the lower right corner is the northern extension of Mylitta Fluctus. The black strip represents missing

Arachnoids

Named by the Soviets for their spider and cobweb-like appearance, arachnoids are one of the more remarkable features found on Venus. They are 50 to 230 km (30 to 138 mi) diameter circular structures, with a central volcanic feature surrounded by a complex network of fractures. Arachnoids are similar in form but generally smaller than coronae. The radar- bright lines extending for many kilometers beyond the arachnoids may have been caused by an upwelling of magma from the interior of Venus, which pushed up the surface to form cracks.

Selu Corona

Located in Lada Terra, Selu Corona measures 350 km (210 mi) in diameter. Coronae are circular to elliptical features marked by a ring of concentric ridges, and are thought to result from the flow of heat in the planet's interior. As hot material rises, it weakens the upper layers of the crust, causing the surface to dome upwards. Then as the region cools, the dome begins to subside. As the upper layers rise and fall, they are subjected to stresses that crack the surface, creating both circular and radial fractures. The black strips represent missing data.

Corona

This region, roughly 100 km (60 mi) on a side, shows a gigantic structure known as a corona. Such features are thought to be the result of hot rising bodies of magma that reach the crust, and cause it to partially melt and collapse, generating volcanic flows and fault patterns that radiate from the central structure. Magellan acquired this view of Venus during its first mapping cycle around the planet in 1990 and 1991.

Sacajawea Patera

Sacajawea Patera is a huge caldera located in western Ishtar Terra. It measures approximately 233 km (140 mi) wide at its base, 1-2 km (0.6 -1.2 mi) deep and 120 by 215 km (74 by 133 mi) in diameter. The caldera is bounded by a zone of graben and fault scarps. Extending up to 140 km (87 mi) in length from the southeast of Sacajawea is a system of linear structures thought to be a flanking rift zone along which the lateral injection and eruption of magma may have occurred.

Domical Hills

Seven circular domes can be seen on the eastern edge of Alpha Regio. They average 25 km (15 mi) in diameter with maximum heights of 750 m (2475 ft). Some scientists believe they are the result of eruptions of thick lava that flowed from a vent on level ground, resulting in an even lateral pattern of lava. The concentric and radial fracture pattern on the surface of the domes suggests that lava welled up inside the domes, causing the surface to stretch.

Ticks

Scientists nicknamed this type of volcano a tick. About 66 km (41 mi) across at the base, this volcano has a flat, concave summit 35 km (22 mi) in diameter. The sides of the volcano are characterized by radiating ridges and valleys. To the west, the rim of the volcano appears to have been breached by dark lava flows that emanated from a shallow summit pit (5.4 km/3.3 mi in diameter) and traveled west along a channel. The black square represents missing data.

Murcury

Mosaic of Mercury

This photomosaic of the planet Mercury was assembled from individual high-resolution images taken by Mariner 10 shortly before closest approach in 1974. The sun is shining from the right, and the terminator is at about 100 degrees west longitude. Crater Kuiper, named after astronomer Gerard P. Kuiper, can be seen just below the center of the planet's illuminated side. The landscape is dominated by large craters and basins with extensive plains between craters.

Caloris Basin

Seen here is part of the enormous Caloris Basin, which is thought to be similar to the large circular basins found on the moon. Probably formed by a giant impact early in Mercury's history, this basin was subsequently filled by lava flows. The nature of the wrinkle ridges on its floor is arguable: some scientists claim tectonics while others suggest they are due to volcanic flows escaping from fractures.

Southwest Mercury

The southwest quadrant of Mercury is seen in this image taken March 29, 1974, by the Mariner 10 spacecraft. The picture was taken four hours before the time of closest approach when Mariner was 198,000 km (122,760 mi) from the planet. The largest craters seen in this picture are about 100 km (62 mi) in diameter.

Hills of Mercury

Weird terrain best describes this hilly, lineated region of Mercury. Scientists note that this area is at the antipodal point to the large Caloris basin. The shock wave produced by the Caloris impact may have been reflected and focused to the antipodal point, thus jumbling the crust and breaking it into a series of complex blocks. The area covered is about 800 km (497 mi) on a side.

Mercury Close Up

The small, bright halo crater (center) is 10 km (6 mi) in diameter. The prominent crater further left, which has a central peak, is 30 km (19 mi) across. The darker, lightly cratered area (upper left) may be an ancient lava flow. Mercury's surface is similar to that of Earth's moon, where a history of heavy cratering is followed by volcanic filling.

Welcome to Planets

This is a collection of many of the best images from NASA's planetary exploration program. The collection has been extracted from the interactive program "Welcome to the Planets" which was distributed on the Planetary Data System Educational CD-ROM Version 1.5 in December 1995. It has also been updated with the addition of more recent images. Please note: This collection replaces the former on-line version of Welcome to the Planets. Internal links within this site are not identical to the old site, so please adjust any links to this site accordingly.

Understanding mineralogy of carbon capture and storage through near infrared spectroscopy

Carbon capture and storage, or geosequestration of carbon dioxide, has been proposed to reduce the greenhouse effect of increased carbon dioxide in the atmosphere. New findings published in the latest edition* of the Journal of Near Infrared Spectroscopy reveal a way to identify and classify the carbonate rocks which would be produced if liquefied CO2 is pumped below the earth’s surface.

Carbon capture and storage, or geosequestration of carbon dioxide, has been proposed to reduce the greenhouse effect of increased carbon dioxide in the atmosphere. New findings published in the latest edition^* of the Journal of Near Infrared Spectroscopy reveal a way to identify and classify the carbonate rocks which would be produced if liquefied CO₂ is pumped below the earth’s surface. Geosequestration involves locking the carbon dioxide in the form of minerals such as smithsonite and magnesium carbonate minerals. Near infrared spectroscopy offers a means of identifying such minerals and may be employed remotely.

The carbonate rocks, such as smithsonites, include some of the most highly coloured and prized precious gem stones. “Here at the Queensland University of Technology we set out to understand the basis of the colour changes in carbonate rocks”, project leader Professor Ray Frost said. “We now understand the significance of very small changes in trace elements (some may call them impurities).” Near infrared spectroscopy is a scientific tool which has helped us understand the colours in these minerals and may be employed to study the colour in gems and jewellery.

The present paper, the sixth in a series on carbonate minerals, employed NIR spectroscopy to reveal differences in mineralogy and mineral composition which related to the origins of the samples. Ray Frost, together with his students and collaborators, are developing the technique of infrared spectroscopy for the study and identification of minerals. Such a study also has relevance to the identification of minerals on Mars and other planets and their moons.

Understanding the matter which makes up our solar system has challenged scientists for centuries. “We are now a step closer to being able to identify which minerals occur on Mars and other planets in the solar system,” Professor Frost said.

These latest studies were undertaken in collaboration with visiting scientist Professor B.J. Reddys at the Queensland University of Technology.

“Here on earth we will be now be able to use visible–near infrared spectroscopy in combination with multispectral remote sensing to greatly enhanced the accuracy of geological mapping,” Professor Frost said. Such remote sensing can be carried out from the air, or even from space.

In the spectra of smithsonite minerals, the main peaks relate, in addition to the anions of OH^– and CO₃^2– to Fe and Cu. The effects of structural cations substitution (Ca²⁺, Fe²⁺, Cu²⁺, Cd²⁺ and Zn²⁺) on band shifts in the electronic spectral region of 11,000 to 7500 cm^–1 (910 to 1330 nm) and vibrational modes of OH^– and CO₃^2– anions in the 7300 to 4000 cm^–1 (1370 to 2500 nm) region were used to distinguish between the smithsonites.

About Journal of Near Infrared Spectroscopy

The Journal of Near Infrared Spectroscopy (JNIRS) is a peer review journal published by IM Publications (www.impublications.com). It publishes high-quality, original research papers on all aspects of near infrared (NIR) spectroscopy and technology. NIR spectroscopy is used widely in the food and agriculture, pharmaceutical and chemical industries, and is finding increasing applications in other areas including medicine and the environment.

Conformational change of proteins probed by laser spray

Seattle, WA (U.S.A.) --- An exciting scientific breakthrough into protein conformation study through a newly-developed laser spray mass spectrometry was reported by Dr. Xianggguo Shi at Yokohama University (Japan) and coworkers last month.

Laser spray, developed by Dr. Shi’s collaborator Prof. Hiraoka at Yamanshi University, is a hybrid of three basic techniques for the generation of gaseous ions from the condensed phase. Laser spray mass spectrometry can faithfully reflect the solution-phase characteristics of biomolecules. Dr. Shi and coworkers have successfully applied laser spray to evaluate the binding affinities of protein-DNA and drug-DNA complexes, which is a topic of importance and challenge in biophysics and medical chemistry.

One of the advantages of laser spray in the analysis of biomolecules is its convenience. Laser spray provides information on the stability of biomolecules instantly just by tuning the laser power. In this recent work, published in the April 2008 issue of Rapid Commun Mass Spectrom, Dr. Shi investigated whether laser spray could be employed to analyze the thermal stability and folding transitions of proteins quantitatively. Horse heart cytochrome c (cyt c, Protein Data Bank (PDB) ID: 1HRS) is a small heme protein, whose molecular weight is 12,365, with 104 amino acid residues and plays an important role in transferring electrons in the respiratory chain. In the reported study, they used cyt c as a model protein to establish the methodology in the conformational study. The stability of horse heart cytochrome c and bovine ubiquitin was evaluated by laser spray and compared in this study.

Researchers found that laser spray mass spectrometry enables much faster and more convenient monitoring of conformational changes of cyt c than does conventional electrospray ionization mass spectrometry (ESI-MS). Laser spray mass spectra of cyt c at various pH were obtained at different levels of laser power. Bimodal charge-state distributions of the protein were observed in laser spray mass spectra, indicating the two-state model of structural change; the lower charges correspond to the folded state, the higher charges to the unfolded state. The results from laser spray mass spectrometry correlated well with circular dichroism (CD) experiments under relatively acidic conditions, which destabilize the protein. The thermal stabilities of ubiquitin and cyt c prepared in solutions at the same pH were also easily differentiated by corresponding laser power. Their exciting studies indicate that laser spray mass spectrometry could be a versatile method for rapid evaluation of the thermal stability of proteins, and for observation of conformational changes by a simple tuning of the laser power.

ESI-MS, developed by John B. Fenn, was used to identify and analyze biological macromolecules in the past decade. Dr. Fenn was awarded the Nobel Prize in Chemistry in 2002 for the contribution in the development of ESI-MS in the biological application. Laser spray mass spectrometry was developed based on ESI-MS, yet Dr. Shi’s groundbreaking research strongly supports that laser spray offers greater advantage than does ESI-MS in the study of the binding affinity of biomolecular complexes and conformational study of proteins. More importantly, laser spray could reflect faithfully the biophysical characteristics of biomolecules, such as binding affinities. These discoveries confirmed that laser spray is a new powerful method to screen drug candidates such as antibiotics and anticancer drugs. This new mass spectrometry technique may win the Nobel Prize for its inventor and his coworkers in the future. We look forward to the new and exciting scientific discoveries from the further development and application of laser spra

GPS Navigation Devices Can Be Spoofed, Counter Measures Not Effective In Certain Cases

Just like flat-screen televisions, cell phones and computers, global positioning system (GPS) technology is becoming something people can't imagine living without. So if such a ubiquitous system were to come under attack, would we be ready?

It's an uncomfortable question, but one that a group of Cornell researchers have considered with their research into "spoofing" GPS receivers.

GPS is a U.S. navigation system of more than 30 satellites circling Earth twice a day in specific orbits, transmitting signals to receivers on land, sea and in air to calculate their exact locations. "Spoofing," a not-quite-technical term first coined in the radar community, is the transmission of fake GPS signals that receivers accept as authentic ones.

The Cornell researchers, after more than a year of building equipment and experimenting in Rhodes Hall, presented a paper on their findings at a meeting of the Institute of Navigation, Sept. 19 in Savannah, Ga.

To demonstrate how a navigation device can be fooled, the researchers, led by Cornell professors Paul Kintner and Mark Psiaki, programmed a briefcase-size GPS receiver, used in ionospheric research, to send out fake signals.

Paper co-authors Brent Ledvina, Cornell Ph.D. '07 and now an assistant professor of electrical and computer engineering at Virginia Tech, and first author Todd Humphreys, Cornell Ph.D. '07, described how the "phony" receiver could be placed in the proximity of a navigation device, where it would track, modify, and retransmit the signals being transmitted from the GPS satellite constellation. Gradually, the "victim" navigation device would take the counterfeit navigation signals for the real thing.

Handheld GPS receivers are popular for their usefulness in navigating unfamiliar highways or backpacking into wilderness areas. But GPS is also embedded in the world's technological fabric. Such large commercial enterprises as utility companies and financial institutions have made GPS an essential part of their operations.

"GPS is woven into our technology infrastructure, just like the power grid or the water system," said Kintner, Cornell professor of electrical and computer engineering and director of the Cornell GPS Laboratory. "If it were attacked, there would be a serious impact."

By demonstrating the vulnerability of receivers to spoofing, the researchers believe they can help devise methods to guard against such attacks.

"Our goal is to inspire people who design GPS hardware to think about ways to make it so the kinds of things we're showing can be overcome," said Psiaki, Cornell professor of mechanical and aerospace engineering.

The idea of GPS receiver spoofing isn't new; in fact, the U.S. government addressed the issue in a December 2003 report detailing seven "countermeasures" against such an attack.

But, according to the researchers, such countermeasures would not have successfully guarded against the signals produced by their reprogrammed receiver.

"We're fairly certain we could spoof all of these, and that's the value of our work," Humphreys said.