Driven by southwesterly winter winds, dust from the White Sands dune field in New Mexico rises thousands of feet from the valley floor and drifts over the snowy peaks of the Sacramento Mountains. Credit: NASA
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It’s clear from this image of why a region in New Mexico, USA is called ‘White Sands.’ The dust plumes in this photograph taken by an astronaut on board the International Space Station show a dust storm in the White Sands National Monument. But this is a huge dust storm. The white dust plumes stretch across more than 120 kilometers (74 miles).
Caused by winds that channel the dust through a low point in the mountains, the vigorous winds are lifting dust particles from the valley floor to more than 1200 meters over the mountains. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite also captured a wider, regional view of the same storm on the same day.
The sand dunes of this national monument are white because they are composed of gypsum, a relatively rare dune-forming mineral. The dunes’ brilliance, especially contrasted against the nearby dark mountain slopes, makes them easily identifiable to orbiting astronauts. The white speck of the dunes was even visible to the Apollo astronaut crews looking back at Earth on the way to the Moon.
In honor of Earth Day, enjoy this beautiful timelapse compiled by science educator James Drake, who put together one of the first ISS flyover videos. This video was created from images produced by the Russian geostationary Electro-L Weather Satellite, and the images are some of the largest whole disk images of our planet, as the satellite is orbiting at about 40,000 km. Each image is 121 megapixels, and the resolution is 1 kilometer per pixel. They are taken every half hour in four different wavelengths of light — three visible, and one infrared. The infrared light is reflected by forests and vegetation, which appear orange in these images. Enjoy!
See more at Drake’s Planet Earth web page, including a zoomable, full resolution image of Earth, as well as other image downloads.
France's Pleiades Earth observation satellite captured this image of the silent Envisat satellite on April 15, 2012, from a distance of about 100 km. Credit: CNES
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ESA’s mysteriously silent Envisat Earth observing satellite has been observed and imaged by another satellite in space. France’s space agency (CNES) pulled off an on-orbit coup, using their high-resolution Pleiades satellite to take a picture of Envisat from about 100 km. The good news is that engineers were able to determine Envisat is fully intact and has not been obviously damaged by impacts by space debris or meteoroids. The massive Envisat fell silent on April 8 after 10 years of service – twice its designed lifetime — providing high quality images and data of our changing Earth.
“We are really grateful to CNES for offering to acquire images of Envisat using their Pleiades and Spot satellites,” said Volker Liebig, ESA’s Director of Earth Observation Programs. “Additional observations being acquired across the globe show how the international space community has come together to track this veteran satellite.”
Previous optical, radar and laser observations of Envisat show it is still in a stable orbit. However, engineers have not even been able to determine if the satellite is in ‘safe mode’ or if it has just gone dead. They say knowing this would be a starting point for revival and the recovery team is drawing on every information source available. If it is in safe mode, it may be possible to re-establish communications.
CNES was able to rotate the Pleiades satellite to capture images of Envisat. These images are being used to determine the orientation of Envisat’s solar panel – the satellite’s power source – to see if it is in a good position to generate power.
Envisat has been helping researchers examine our planet, completing more than 50,000 orbits and returned thousands of images, as well as a wealth of data about the land, oceans and atmosphere.
The Palm and The World Islands, Dubai. Credit: NASA/ESA
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Usually astronauts have to go much farther away than low Earth orbit to see the entire world in one view, but The World Islands resorts in Dubai provides a unique — if not manufactured — view of Earth’s continents from space. The World Islands are a collection of man-made islands shaped into the continents of the world, and ultimately will consist of 300 small private artificial islands divided into four categories – private homes, estate homes, dream resorts, and community islands.
To the east is another man-made archipelago named The Palm, for obvious reasons, and another island chain is due to be built between these reclaimed lands which will be called The Universe.
ESA astronaut André Kuipers took this image on April 10, 2012 during his long duration mission on the International Space Station. See more of his images at the ESA FLickr page.
A 'Blue Marble' image of the Earth taken from the VIIRS instrument aboard NASA's most recently launched Earth-observing satellite - Suomi NPP. This composite image uses a number of swaths of the Earth's surface taken on January 4, 2012. Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring.
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A new high-definition version of the ‘Blue Marble’ has been taken from the newest Earth observation satellite. The just-renamed Suomi NPP satellite took numerous images on January 4, 2012 and this composite image was created from several “swaths” of Earth. It is a stunningly beautiful look at our home planet, with the largest versions of the image showing about 1.6 km (1 mile) per pixel. This Sun-synchronous Earth-orbiting satellite is 824 kilometers (512 miles) above Earth, and it gets a complete view of our planet every day. It is the first of a new generation of satellites that will observe many facets of how our Earth may be changing.
Originally launched as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP), it was just renamed ‘Suomi NPP’ on to honor a pioneer in the use of satellites, the late Verner E. Suomi.
See below for an image showing these “swaths” from global images taken on November 24, 2011.
The Suomi NPP satellite gets a complete view of our planet every day. This image uses 20 orbital ‘swaths’ from November 24, 2011, and is the first complete global image from the VIIRS instrument. Credit: NASA Earth Observatory.
These images were taken with the The Visible/Infrared Imager Radiometer Suite or VIIRS instrument aboard Suomi NPP.
VIIRS images the surface in long wedges measuring 3,000 kilometers (1,900 miles) across. The swaths from each successive orbit overlap one another, so that at the end of the day, the sensor has a complete view of the globe. The Arctic is missing because it is too dark to view in visible light during the winter.
The NPP satellite was placed in a Sun-synchronous orbit, so its path takes the satellite over the equator at the same local (ground) time in every orbit. This orbit allows the satellite to maintain the same angle between the Earth and the Sun so that all images have similar lighting. This consistent angle is important because it allows scientists to compare images from year to year without worrying about extreme changes in shadows and lighting.
Suomi NPP is carrying five instruments on board, and the biggest and most important instrument is VIIRS.
Unfortunately, an anomaly has been discovered in the instrument. During the checkout phase after it launched in October 2011, engineers detected a larger than expected decrease in sensor sensitivity in four of VIIRS’s near-infrared and visible channels.
An analysis revealed an anomalous material on the surface of the mirror, and further investigation on the ground discovered a non-standard process that occurred during the mirror coating as a potential source of tungsten oxide contamination on the VIIRS mirrors. Tungsten oxides could cause the surface of the mirror to darken.
This evidence suggests that the cause of the contamination is limited to the VIIRS instrument, and is not a concern for other NPP instruments. Officials from NPP said that while this problem is likely irreversible, the darkening of the VIIRS mirror caused by the contamination is expected to reach a plateau and remain at that level for the life of the mission. Although testing on this issue is continuing, NPP mission managers expect this plateau to still provide sufficient margins to allow VIIRS to meet its design requirements.
Still, the images have been spectacular so far from Suomi NPP and we look forward to more high definition views of our Blue Marble.
Satellite view from the Advanced Land Imager on the Earth Observer 1, showing a brand new volcanic island in the Red Sea. Credit: NASA
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Want to get away from it all? Here’s the newest deserted island on Earth. In late December, we reported on a volcanic eruption in the Red Sea that appeared to have created a brand new island. The eruption has now stopped and on January 15, 2012 the Advanced Land Imager on the Earth Observer-1 satellite captured a clear, cloud- and volcanic plume-free view of this newly formed land mass. The new island is part of the Zubair Islands, located about 60 kilometers (40 miles) off the coast of Yemen. The new island and its older family members poke above the sea surface, rising from a shield volcano. This region is part of the Red Sea Rift where the African and Arabian tectonic plates pull apart and new ocean crust regularly forms.
If you want to visit, just watch out for hot lava pits and almost certain future eruptions.
The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this high-resolution, natural-color images on December 23, 2011 showing an island being formed in the Red Sea. Credit: NASA
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Looking for some new lake-front property? Here’s the newest available on the planet. Volcanic activity in the Red Sea that started in mid-December has created what looks like a new island. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured a high-resolution, natural-color image on December 23, 2011 showing an apparent island where previously there was none. Here, a thick plume of volcanic ash still rises from the new island.
See below for an image from 2007 of the same region.
Satellite image of the same region from October 24, 2007. Credit: NASA
According to the NASA Earth Observatory website, the volcanic activity occurred along the Zubair Group, a collection of small islands off the west coast of Yemen. The islands poke above the sea surface, rising from a shield volcano. This region is part of the Red Sea Rift where the African and Arabian tectonic plates pull apart and new ocean crust regularly forms.
According to news reports, fishermen witnessed lava fountains reaching up to 30 meters (90 feet) tall on December 19.
In 1989, meteorologists discovered sprites. Not the spirits, elves, or pixies that pepper Shakespearean comedies but their equally elusive electrical namesakes. Lightning sprites are large scale electrical discharges inside the clouds above storms that make the upper atmosphere glow, sort of like a fluorescent lightbulb.
Meteorologists have already determined that sprites likely aren’t unique to Earth. In fact, this elusive form of lightning might be common throughout the solar system. Now, researchers at Tel Aviv University are asking whether the presence of sprites on other planets could indicate the presence of organic material in their atmospheres.
The layers of our atmosphere. Image credit: National Weather Service, JetStream Online School for Weather.
Though not an uncommon phenomena, sprites are incredibly hard to find and observe. They can only be captured with highly sensitive high speed cameras. Sprites occur in the Earth’s Mesosphere, layer between the stratosphere and the thermosphere – about 50 km (31 miles) to 90 km (56 miles) high. At this altitude, the gases that make up our atmosphere are much thinner and unable to hold heat from the Sun making the average temperature a chilly 5°F (-15°C) to as low as -184°F (-120°C).
But gases at this altitude are still thick enough to slow meteors – this is where they burn up and create what we see as meteor showers. Gases in the mesosphere are also thick enough to light up with sprites, providing a window into the composition of our atmosphere. Sprites, which glow reddish-orange, indicate the kinds of molecules present in this layer of the atmosphere.
Lightning isn’t a rare occurrence in our solar system, which leads researchers to suspect sprites might be found on Jupiter, Saturn, and Venus – all planets with the right environment for strong electrical storms. Just like on Earth, sprites found on these planets could open a window in their atmospheric composition, conductivity, and possibly point to the presence of exotic compounds.
Jupiter and Saturn present the most exciting environments. Both gas giants experience lightening storms with flashes more than 1,000 as powerful as those found on Earth. It’s on these planets that Ph.D. student Daria Dubrovin, with her supervisors Prof. Colin Price of Tel Aviv University’s Department of Geophysics and Planetary Sciences and Prof. Yoav Yair at the Open University of Israel, is focussing on.
Dubrovin has re-created these planetary atmospheres in a lab to study the presence of sprites in space. Or, as she describes her work, “We make sprites in a bottle.” She hopes this will provide a new understanding of electrical and chemical processes on other planets.
A sprite as it might appear in Saturn's atmosphere, created in a TAU lab. Image credit: American Friends, Tel Aviv University
What’s more, understanding lightning on other worlds could help researchers understand the possibility of life on other worlds. As Dubrovin points out, lightning is commonly accepted as the generator of organic molecules that turned early Earth’s ocean into the life-filled primordial soup. Increased study of lightning on other planets could give another clue into the presence of extraterrestrial life. Their research could easily be applied to exoplanets, not just bodies in our solar system.
A lightning storm on Saturn has Dubrovin pretty excited. It’s currently producing over 100 electrical flashes per second, a rare occurrence even within the planet’s volatile cloud layers. If researchers could successfully gather images of higher altitude sprites from the Cassini spacecraft (currently in orbit around Saturn), it would not only yield information on the storm below but also add to the general knowledge base of sprites and lightning on other planets.
NASA' Terra satellite captured cloud streets in Hudson Bay, Canada on November 20, 2011 at 12:25 p.m. EST (17:25 UTC). Credit: NASA
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I love looking at unusual cloud formations, and these have to be some of the most intriguing. These long, horizontal rolls of clouds are called “cloud streets” and NASA’s Terra satellite had a “drive by” of these clouds, observing them over Hudson Bay, Canada on November 20, 2011 at 12:25 p.m. EST (17:25 UTC). These rows of clouds stretch from northwest to southeast over the Hudson Bay.
Cloud streets are long lines or bands of cumulus clouds that usually form within the lower one to three kilometers of the atmosphere, and come from eddies in the atmosphere.
According to NASA’s Earth Observatory and the Goddard Space Flight Center Flickr page, cloud streets form when cold air blows over warmer waters, while a warmer air layer—or temperature inversion—rests over top of both. The comparatively warm water of Hudson Bay gives up heat and moisture to the cold air mass above, and columns of heated air—thermals—naturally rise through the atmosphere. As they hit the temperature inversion like a lid, the air rolls over like the circulation in a pot of boiling water. The water in the warm air cools and condenses into flat-bottomed, fluffy-topped cumulus clouds that line up parallel to the wind.
Hudson Bay is a large body of saltwater located in northeastern Canada. Also in the image, are several snow-covered islands in Hudson Bay. The larger island to the north is South Hampton Island, and the smaller island east is Coats Island, and further east is Mansel Island.
What more can we say? The view from the International Space Station is incredible, and this latest time-lapse sequence of photographs was put together by Michael König. These views are taken with a special low-light 4K-camera now on the Space Station, and covers August to October, 2011. The crews of expedition 28 & 29 were behind the camera, while König refurbished, smoothed, retimed, denoised, deflickered, and cut, etc. You can see all the images taken with this new camera at the Image Science & Analysis Laboratory website, The Gateway to Astronaut Photography of Earth
