Prominent View

The Sun is constantly roiling with nuclear heat and intense magnetism that make sunspots, flares, coronal mass ejections, and all sorts of space weather. When directed toward Earth, those solar blasts can disrupt satellite and radio communications, damage our electric-powered tools and toys, and create auroras.

But it is not always easy to know when the Sun is spitting plasma and energy in our direction. This is why NASA launched the Solar Terrestrial Relations Observatory, or STEREO, in October 2006. The twin satellites were sent out along roughly the same orbit around the Sun as the Earth itself. The orbit of STEREO-A (ahead) is slightly closer to the Sun and moving faster than Earth; the STEREO-B (behind) orbit is slightly farther from the Sun and moving a little slower than our planet. The difference in speed creates separation between the satellites and a stereoscopic view of our nearest star.

The images above show the surface of the Sun from two different angles on October 14, 2012. The top image is from STEREO-B and shows a dark vertical stripe on the upper middle face of the Sun. The lower image comes from STEREO-A, which was more than 90 degrees ahead of STEREO-B; that is, somewhat beyond a right angle from that vertical stripe. In the lower image, the vertical stripe instead shows up as a large loop stretching into the solar atmosphere, or corona.

The stripe and the loop are differing views of the same dense mass of electrified gas (plasma) held in place by a magnetic field. When viewed straight on, as in the STEREO-B image, the line of plasma appears darker because it is relatively cooler than the solar surface below. (More of its energy is magnetic than radiant.) Solar scientists call these dark lines “filaments.” When viewed from the side, however, the line of plasma looks like a bright loop stretched out against the blackness of space; solar physicists call this a prominence. Essentially, filaments and prominences are the same phenomenon, just viewed from a different perspective.

As of September 1, 2012, STEREO-A and STEREO-B formed an equal-sided triangle together with NASA’s Solar Dynamics Observatory (SDO), which views the Sun from orbit around Earth. This geometry allowed the three craft to provide overlapping views of the entire Sun. It also allows solar physicists to study solar events in three dimensions.

1.  Further Reading

2.   NASA STEREO Mission.

3.   NASA STEREO Science team.

NASA image courtesy of the STEREO science team. Caption by Mike Carlowicz, based on information from Karen Fox 

Ashfall from the Karymsky Volcano

The Karymsky stratovolcano stands 1,536 meters (5,039 feet) above sea level, and most of its eruptions and occasional lava flows originate from the summit. Karymsky is the most active of Kamchatka’s eastern volcanoes, with almost constant (on a geologic time scale) volcanism occurring since at least the late 18th century, when the historical record for the region began.

Because of the high levels of volcanic activity on the Kamchatka Peninsula, the Kamchatka Volcanic Eruption Response Team (KVERT) monitors the activity levels of several volcanoes and issues updates including aviation alerts and webcams. KVERT reported moderate seismic activity at Karymsky between November 2–9, 2012. Such activity can indicate the movement of magma beneath or within a volcanic structure and that an eruption may be imminent. The Tokyo Volcanic Ash Advisory Center (VAAC) subsequently reported an explosive eruption at Karymsky on November 9 at 22:15 Universal Time.

This astronaut photograph of the resulting ash plume was taken approximately 1 hour and 35 minutes after the eruption began. The plume extends from the summit of Karymsky to the southeast, with brown ash deposits darkening the snow cover below the plume.

The Akademia Nauk caldera—now filled with water to form the present-day Karymsky Lake—is located to the south of Karymsky volcano. Calderas are formed by explosive eruption and emptying of a volcano’s magma chamber, leading to collapse of the structure to form a crater-like depression. Akademia Nauk last erupted in 1996.

Astronaut photograph ISS033-E-19822 was acquired on November 9, 2012, with a Nikon D3S digital camera using an 800 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 33 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.

Instrument: 

ISS - Digital Camera

Falkland Islands

About 400 million years ago, some of the rocks that make up the Falkland Islands were part of the supercontinent ofGondwana, crunched between southern Africa and what is now Queen Maud Land, Antarctica. When tectonic forces tore Gondwana apart, the Falkland Islands were left behind like crumbs as a massive geologic cookie was split into pieces.

Today, the islands are situated about 600 kilometers (400 miles) east of Argentina and 1,350 kilometers (850 miles) north of the Antarctic Circle. There are 778 islands in this territory of the United Kingdom, but just two large islands—East Falkland and West Falkland—comprise the bulk of the Connecticut-sized landmass.

The Falkland Islands have a cool, moist climate that varies minimally throughout the year. Average annual temperatures are about 5.6°C (42°F). Temperatures reach as high as 24°C (76°F) in summer and as low as -5°C (22°F). Rainfall is comparatively low and evenly distributed throughout the year, averaging 625 millimeters (25 inches) in Stanley, the capital city.

Few trees grow on the islands. Intead, grassland and heath—which is widely used as pastureland for sheep and cattle—dominate the landscape. The islands are home to nearly 500,000 sheep and 5,000 cattle, and the animals far outnumber the 2,600 people permanent human residents. About 80 percent of the people reside in Stanley.

Farmers often burn pastureland in the early spring to encourage growth. When ewes and lambs are born, they move the young animals to recently-burned areas to graze. On November 17, 2012, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’s Aqua satellite captured a glimpse of a few of agricultural fires west of Stanley. Red outlines indicate hot spots where MODIS detected the unusually warm surface temperatures associated with fires.

The same satellite instrument captured another view of agricultural fires on East Falkland in October 2012.

·      References

·      CIA. (n.d.) Falkland Islands. Accessed November 19, 2012.

·      British Geological Survey. (n.d.) The Geology of the Falkland Islands. Accessed November 19, 2012.

·      Falkland Islands Government. (n.d.) Falkland Islands. Accessed November 19, 2012.

·      Falkland Islands Government. (n.d.) Farming in the Falkland Islands. Accessed November 19, 2012.

NASA image by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Adam Voiland.

Instrument: 

Fires Across Cape York Peninsula

Summer bushfires near densely-populated areas in southern Australia attract the most public attention, but the continent’s largest and most frequent fires actually occur in the spring in the tropical savannas of northern Australia.

On November 25, 2012, the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard

NASA’s Aqua satellite captured this natural-color image of wildfires burning on Cape York Peninsula, the northernmost part of Australia. Smoke plumes from multiple fires are visible streaming west; red outlines indicate hot spots where MODIS detected unusually warm surface temperatures associated with fires.

Three main meteorological variables affect fire behavior: atmospheric humidity, air temperature, and wind strength. On Cape York Peninsula, humidity drops and temperatures rise beginning with the arrival of the dry season in March. By the end of November, grasses and woodland trees in the region have reached their most flammable state. In this case, steady winds (about 20 kilometers/12 miles per hour) have helped sustain fires that were likely started by lightning and human activity.

About half of the savanna woodlands on Cape York Peninsula burn either every year or so, typically late in the dry season. Dried grasses, which receive ample sunshine and rain during the wet season, provide the bulk of the fuel. As the dry season progresses, trees also drop loads of leaves and twigs that help fuel fires. Key grasses and trees in the region include Sorghum, Eucalyptus, and Corymbia.

Despite the frequency of the burning, wildfires on Cape York Peninsula are generally less severe than in southern Australia because fungi, bacteria, and other decomposers that thrive in the region continuously break dried grass and leaf litter down. Fewer decomposers live in southern Australia, making it possible for leaf litter and other fuel to build up for decades and prime the landscape for extremely destructive fires.

·      References

·      NAFI. (2012, Nov. 27) North Australia fire information map: Cape York. Accessed Nov. 27, 2012.

·      NASA. (2012, Nov. 27) Cape York Peninsula fires. Accessed Nov. 27, 2012.

·      Queensland Government. (n.d.) Rural fire service. Accessed Nov. 27, 2012.

·      Savannah Explorer. (n.d.) Fire in Australia’s tropical savannas. Accessed Nov. 27, 2012.

1.    Further Reading

2.     CSIRO. (2012, Oct. 26). Bushfire in Australia. Accessed Nov. 27, 2012.

3.     Crowley, G.M. (2008, Oct. 9). Changing fire management in the pastoral lands of Cape York Peninsula of northeast Australia. Geographical Research.

Central Kamchatka Volcanoes, Russian Federation

The snow-covered peaks of several volcanoes on the central Kamchatka Peninsula stand above a fairly uniform cloud deck that obscures the surrounding lowlands. In addition to the rippled cloud patterns—caused by interactions of air currents and the volcanoes—a steam and ash plume is visible extending north-northeast from the relatively low summit (2,882 meters above sea level) of Bezymianny volcano. Volcanic activity in this part of Russia is relatively frequent, and well monitored by Russia’s Kamchatka Volcanic Eruption Response Team (KVERT). The KVERT web siteprovides updated information about activity levels on the peninsula, including aviation alerts and webcams.

Directly to the north and northeast of Bezymianny, the much larger and taller stratovolcanoes Kamen (4,585 meters above sea level) and Klyuchevskaya (also Kliuchevskoi) (4,835 meters) are visible. Klyuchevskaya is Kamchatka’s most active volcano; it last erupted in 2011, whereas Kamen has not erupted during the recorded history of the region. The most recent activity at the volcanic massif of Ushkovsky (3,943 meters) was an explosive eruption in 1890.

To the south of Bezymianny, the peaks of Zimina (3,081 meters above sea level) and Udina (2,923 meters) volcanoes are just visible above the cloud deck; no historical eruptions are known from either of them. While the large Tobalchik volcano to the southwest is largely formed from a basaltic shield volcano, its highest peak (3,682 meters) is formed from an older stratovolcano. Tobalchik last erupted in 1976.

While this image may look like it was taken from a passenger airplane, in fact it was taken from the considerably higher altitude of the International Space Station (ISS). At the time the image was taken, the ISS was located approximately 417 kilometers above the Sea of Okhotsk and more than 700 kilometers to the southwest of the volcanoes. The combination of the low viewing angle, the shadows, the height, and the distance from the volcanoes contributes to the appearance of a topographic relief map.

Astronaut photograph ISS033-E-18010 was acquired on November 3, 2012, with a Nikon D3S digital camera using an 800 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 33 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.

Instrument: 

ISS - Digital Camera

Prominent View

The Sun is constantly roiling with nuclear heat and intense magnetism that make sunspots, flares, coronal mass ejections, and all sorts of space weather. When directed toward Earth, those solar blasts can disrupt satellite and radio communications, damage our electric-powered tools and toys, and create auroras.

But it is not always easy to know when the Sun is spitting plasma and energy in our direction. This is why NASA launched the Solar Terrestrial Relations Observatory, or STEREO, in October 2006. The twin satellites were sent out along roughly the same orbit around the Sun as the Earth itself. The orbit of STEREO-A (ahead) is slightly closer to the Sun and moving faster than Earth; the STEREO-B (behind) orbit is slightly farther from the Sun and moving a little slower than our planet. The difference in speed creates separation between the satellites and a stereoscopic view of our nearest star.

The images above show the surface of the Sun from two different angles on October 14, 2012. The top image is from STEREO-B and shows a dark vertical stripe on the upper middle face of the Sun. The lower image comes from STEREO-A, which was more than 90 degrees ahead of STEREO-B; that is, somewhat beyond a right angle from that vertical stripe. In the lower image, the vertical stripe instead shows up as a large loop stretching into the solar atmosphere, or corona.

The stripe and the loop are differing views of the same dense mass of electrified gas (plasma) held in place by a magnetic field. When viewed straight on, as in the STEREO-B image, the line of plasma appears darker because it is relatively cooler than the solar surface below. (More of its energy is magnetic than radiant.) Solar scientists call these dark lines “filaments.” When viewed from the side, however, the line of plasma looks like a bright loop stretched out against the blackness of space; solar physicists call this a prominence. Essentially, filaments and prominences are the same phenomenon, just viewed from a different perspective.

As of September 1, 2012, STEREO-A and STEREO-B formed an equal-sided triangle together with NASA’s Solar Dynamics Observatory (SDO), which views the Sun from orbit around Earth. This geometry allowed the three craft to provide overlapping views of the entire Sun. It also allows solar physicists to study solar events in three dimensions.