February Puzzler

February 24th, 2014 by Adam Voiland

february_puzzler_2014

Every month we offer a puzzling satellite image here on Earth Matters. The February 2014 puzzler is above. Your challenge is to use the comments section to tell us what the image shows, what part of the world we are looking at, when the image was acquired, and why the scene is interesting.

How to answer. Your answer can be a few words or several paragraphs. (Try to keep it shorter than 200 words). You might simply tell us what part of the world an image shows. Or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure speck in the far corner of an image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t offer prize money, but, we can promise you credit and glory (well, maybe just credit). Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people who offer the most interesting tidbits of information. Please include your preferred name or alias with your comment. If you work for or attend an institution that you want us to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the last few months or work in geospatial imaging, please sit on your hands for at least a few days to give others a chance to play.

Releasing Comments. Savvy readers have solved many of our puzzlers after only a few minutes or hours. To give more people a chance to play, we may wait between 24-48 hours before posting the answers we receive in the comment thread.

A Quick Guide to NASA’s Newest Satellite

February 20th, 2014 by Adam Voiland

Global Precipitation Measurement (GPM) is a name worth remembering. First of all, it’s a satellite.  On February 27, 2014, GPM’s Core Observatory is scheduled to rocket into space from Japan’s Tanegashima Space Center carrying a radar and radiometer capable of measuring precipitation in new ways.

However, this joint NASA/JAXA mission is bigger than just one satellite. The scientists behind GPM are hoping that the core observatory will function like a key that “unlocks” and unifies data collected by a whole constellation of existing and future satellites.

GPM Constellation 1-13-14

 

For instance, an earlier precipitation-monitoring satellite called the Tropical Rainfall Measuring Mission (TRMM) also used radar to measure precipitation, but it could only detect moderate and heavy rain in tropical areas. GPM, in contrast, will also sense light rain and snow and will see nearly to the poles (65 degrees latitude north and south), meaning it will extend and improve upon TRMM’s measurements.

Expect to hear a lot more about this satellite over the next few weeks. There’s a lot of information to sift through if you want to learn more about the mission, but some of it can be tricky to find. To make the sifting a little easier, I’ve compiled a “best of guide” to images and other resources about the mission to make your search a little easier.  Stay tuned for more, follow the mission via @NASA_Rain and on Facebook, and enjoy the launch.

 

Videos Worth Watching

More videos at  http://www.youtube.com/playlist?list=PL_8hVmWnP_O258ZS4-HKumKTfX7f72LHA

 

Precipitation 101
water_cycle
Find out more details about precipitation and GPM’s science goals at
http://pmm.nasa.gov/GPM/science-objectives
http://pmm.nasa.gov/science
http://www.jaxa.jp/countdown/f23/overview/dpr_e.html
http://www.nasa.gov/mission_pages/GPM/science/index.html#.UwYyP_1Jwns

 

Image Galleries
gpm-encapsulation
See image galleries at
http://jda.jaxa.jp/category_p.php?lang=j&page=&category1=256&category2=257&category3=263&page_pics=50
http://gpm/multimedia/images/GPM
http://www.nasa.gov/mission_pages/GPM/multimedia/index.html#.UweJDyRsjJ4

The Human Dimension
Applications_Banner_v1

Find out how GPM will affect life on the ground at
http://pmm.nasa.gov/applications
http://www.nasa.gov/mission_pages/GPM/applications/index.html#.UweGTyRsjJ4

The Nuts and Bolts
GPM-Core-diagram-extended-FINAL2
Find out more about the instruments and technical details of the core observatory at
http://pmm.nasa.gov/GPM/flight-project/spacecraft-and-instruments
http://www.jaxa.jp/countdown/f23/overview/gpm_e.html
http://www.nasa.gov/mission_pages/GPM/spacecraft/index.html#.UwYwt_1Jwns

Learn more about the HII-A Rocket that will launch GPM into orbit at http://pmm.nasa.gov/launch

http://www.jaxa.jp/projects/rockets/h2a/index_e.html
http://www.jaxa.jp/projects/rockets/h2a/design_e.html
http://svs.gsfc.nasa.gov/vis/a010000/a011100/a011129/index.html


Want even more detailed information?

See the Bulletin of the Bulletin of the American Meteorological Society paper at
http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-13-00164.1

Or read the launch brochure at http://eospso.gsfc.nasa.gov/content/gpm-core-observatory-pre-launch-brochure

The Landsat 5 Photobomb

February 18th, 2014 by Holli Riebeek

It’s funny what you can find in a satellite image. Mike Gartley, a research scientist at Rochester Institute of Technology, spotted the Landsat 5 satellite lurking in a Landsat 8 image of northwestern Brazil.

Landsat 5

Landsat 5 is just a few blurry pixels in Landsat 8′s panchromatic band.

Landsat 5 once flew in the orbit that Landsat 8 now lives in. But in January 2013, the U.S. Geological Survey lowered L5′s orbit about 23 kilometers (14 miles)  as part of the decommissioning process. The satellite is now in a disposal orbit, slowly being dragged back to Earth.

Landsat 8, meanwhile, reached its final orbiting altitude of 705 kilometers (438 miles) on April 12, 2013. On November 22, Landsat 8 flew over the defunct Landsat 5 satellite, capturing this view of its predecessor. Landsat 5 is just a few pixels across and is only visible at all  because it is much closer to Landsat 8 than it is to Earth. See additional images from the November 22 overflight on NASA’s Landsat web site.

Finding Landsat 5 in the image was a matter of course for Gartley, who routinely hunts for space objects in Landsat images. As of December 2011, more than 22,000 “resident space objects” were in orbit around the Earth. The Space Surveillance Network tracks all of these objects with telescopes, radars, and a computer model. Gartley uses this information to figure out when an object will fly into Landsat 8′s view.

“Believe it or not, there are anywhere from 1 to 4 such underflights of space objects that are passing through the field of view of Landsat 8 on any given day,” says Gartley. “Many of the objects are old rocket bodies and COSMOS satellites (Tselina-D ELINT type), while the ISS has also popped up at least three times since last May.”

International Space Station

The International Space Station seen from Landsat 8.

Landsat 5′s appearance is appropriate: it’s the satellite that just won’t go away. The tenacious satellite was built to operate for 3 years, but worked for more than 29, setting a world record for the longest operating Earth observation satellite. Even the decommissioning process took longer than expected because the satellite kept running. Hear the story from longtime flight systems manager for Landsat 5, Steve Covington, in this recorded talk originally given at the Library of Congress:

Reader Pics: Blooms in the Water

February 5th, 2014 by Mike Carlowicz

Last week we shared an image of an 800-kilometer long bloom of marine protists off the coast of Brazil. In satellite imagery, the bloom appeared navy to black in color, even though the species—Myrionecta rubraappears red when viewed close-up. The blooms tend to occur just below the water surface, so much red light that the protists reflect gets absorbed before it returns to the satellite. Here’s a look at the January bloom from a boat in the South Atlantic.

Brazil bloom closeup 1

The photos were taken in the late afternoon on January 22, 2014. The boat was positioned at roughly 24° 08′ South and 45° 07′ West. The water temperature was 29°Celsius (84°Fahrenheit) and the depth was 70 meters (230 feet).

 

Brazil bloom closeup 2

Thanks to Julio Cardoso, a boater and amateur scientist from Brazil who shared the photos with us. Thanks are due as well to Dr. Aurea Maria Ciotti of the Universidade de São Paulo, who helped us identify the species and the nature of the bloom.

As of February 5, 2014, the bloom appeared to be subsiding, though clouds and haze made it difficult to see clearly from satellites. You can continue to monitor the area by clicking here.

Reader Pics: Sundogs

February 3rd, 2014 by Adam Voiland

sundog_jones

Halos have a long and rich history in religious art, usually symbolizing the presence of someone or something divine.  In the physical sciences, the beautiful displays of light are a sign of something more ordinarythe presence of hexagonal, plate-shaped ice crystals that make up cirrus clouds.  As gravity pulls the ice crystals downward, their faces become horizontal with the ground and they function as dispersive prisms, breaking sunlight into separate colors and leaving rainbow-like ice crystal halos in the sky.

Sundogs are one of the most common types of ice halo. They occur when light rays enter the side of an ice crystal and leave through another side inclined about 60 degrees to the first. (See Atmospheric Optics for a good diagram that illustrates the process.) Sundogs are most easily seen when the Sun is low in the sky; the halos occurring on either side of it at about 22 degrees. The part of a sundog closest to the Sun always forms a layer of red, while greens and blues form beyond that. Sundogs are visible all over the world and at any time of year, regardless of the temperature at the surface. For more imagery of sundogs and other optical phenomena (such as sun pillarscircumhorizonatal arcs, and parhelic circles), it’s worth checking out the archives of Earth Science Picture of the Day.

In the last few weeks, we’ve had a number of readers send us their photographs of sundogs.  The image above was taken by Nina Garcia Jones; the image below comes from Isa DeSil. Thanks for sending the photos our way. To the rest of our readers: keep your interesting photos of atmospheric, meteorological, or geological phenomena coming. We’ll occasionally post the best images on this blog, and we’ll do what we can to help explain the science behind them.

Griselda-Meza_sungdogs

ellesmere_ali_2012171

Congratulations to Dillion and Eric J.F. Kelijssen for solving the January Puzzler the fastest.  The answer is Oobloyah Valley on Canada’s Ellesmere Island. The image features four glaciersNukapingwa, Arklio, Perkeo, and Midgetflowing into the valley from the Krieger mountains to the north. At the end of each glacier, all of which are retreating, there are heaps of rock, gravel, and sand known as terminal moraines. As we explained in our Image of the Day on January 18, 2014, the moraines are of interest to ecologists because they offer an ideal natural laboratory for studying how plant species colonize recently exposed terrain.

One team of researchers led by Yokohama National University’s Akira S. Mori focused their search for Arctic plants on the moraine created by Arklio Glacier, the second to the left in the image above. (The Advanced Land Imager acquired this image of the glacier on June 19, 2012.) The moraine, which formed during the Little Ice Age, appears as a lobe-shaped bulge around the end of glacier. The light brown feature south of the moraine is a stream bed. The scientists found two dominant pioneer species living on the rocky, virtually soil-free moraine. The first is Epilobium latifolium, a flowering plant in the evening primrose family known as Dwarf fireweed. The second is Salix arctic, a type of creeping willow.

See Arklio’s terminal moraine and Epilobium latifolium (right) and Salix arctic (left) in the photographs below.

arkliomoraine

The snout of Arklio Glacier with its terminal moraine visible at the center of the image.  An earlier study of the area’s vegetation occurred at Moraine D. Image courtesy of Akiro Mori, Yokohama National University.

salixarctic-epilibium-latifolium

The dominant vascular pioneer plants that grow on Arklio Glacier’s moraine: Epilobium latifolium (right) and Salix arctica (left). Image courtesy of Akiro Mori, Yokohama National University.

Best of the Archives: Dunes of the Great Bahama Bank

January 16th, 2014 by Adam Voiland

bahamas_etm

Thirteen years ago, a satellite acquired this beautiful image (above) of light and sand playing off a portion of the ocean floor in the Bahamas. The caption that accompanied the image didn’t include many details, only noting that the image was acquired by the Enhanced Thematic Mapper Plus (ETM+) sensor on Landsat 7 and that, “tides and ocean currents in the Bahamas sculpted the sand and seaweed beds into these multicolored, fluted patterns in much the same way that winds sculpted the vast sand dunes in the Sahara Desert.”

An image as beautiful as this seemed like it deserved a bit more explanation, so I  grabbed a recent (January 9, 2014) scene of the same area captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. That image (below) shows a much broader view of the area. You can still see some details of the intricate network of dunes, but the MODIS image offers a much better sense of the regional geology.  For instance, you can easily see that the section of dunes shown in the first image (the white box in the lower image) is part of a much larger limestone platform called the Great Bahama Bank. Limestone is a sedimentary rock formed by the skeletal fragments of sea creatures, including corals and foraminifera, and this particular limestone platform has been accumulating since at least the Cretaceous Period. 

You can also see a sharp division between the shallow (turquoise) waters of the Great Bahama Bank and the much deeper (dark blue) parts of the ocean. The submarine canyon that separates Andros Island from Great Exuma Island is nearly cut off entirely from the ocean by the Grand Bahama Bank, but not quite.  A connection to deep waters to the north gives the trench the shape of a tongue, earning the feature the name “Tongue of the Ocean.” At its lowest point, the floor of the Tongue of the Ocean is about 14,060 feet (4,285 meters) lower than Great Bahama Bank. The shallowest (lightest) parts of the Grand Bahama Bank, in contrast, are just a few feet deep.

Bahamas_amo_2014009

January Puzzler

January 13th, 2014 by Adam Voiland

January_Puzzler_2014
Every month we offer a puzzling satellite image here on Earth Matters. The January 2014 puzzler is above. Your challenge is to use the comments section to tell us what the image shows, what part of the world we are looking at, when the image was acquired, and why the scene is interesting.

How to answer. Your answer can be a few words or several paragraphs. (Try to keep it shorter than 200 words). You might simply tell us what part of the world an image shows. Or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure speck in the far corner of an image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t offer prize money, but, we can promise you credit and glory (well, maybe just credit). Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people who offer the most interesting tidbits of information. Please include your preferred name or alias with your comment. If you work for an institution that you want us to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the last few months or work in geospatial imaging, please sit on your hands for at least a few days to give others a chance to play.

Releasing Comments. Savvy readers have solved many of our puzzlers after only a few minutes or hours. To give more people a chance to play, we’re going to wait between 24-48 hours before posting the answers we receive in the comment thread.

December Puzzler Answer: The Gulf Stream

December 23rd, 2013 by Adam Voiland

Every month we offer a puzzling satellite image here on Earth Matters. Every month someone seems to figure it out quickly. So in December 2013, we threw down the gauntlet.

For the first time, we put a false-color imagethis swirl of purple and pinkinto play. A week later, we have received many thoughtful responses but no one came up with the answer. The puzzler this month was a swatch of the Gulf Stream as seen in the infrared by the Thermal Infrared Sensor on Landsat 8.

A number of you came pretty close. Kevin Acosta was one of the first to speculate that we were looking at ocean currents, though he guessed it was the Benguela and Agulhas currents south of South Africa. Eric pointed out it was a false-color image of heat, but he was focused on the Great Lakes as opposed to ocean currents.

I was impressed by the sheer diversity of ideas that flowed in. I’ve included a few of the more creative responses below.

“Looks like part of a red algae bloom or ‘red tide’ on the oceans surface. Can be very beautiful, but can also be deadly when seafood gathered from an algae site is consumed.”  M. Lowe, Earth Matters

“Looking at the gas cloud produced after an eruption using thermal imagery probably underwater hence the blue at top of picture. Recent off Japanese coast.”  Duane Elliott, Facebook.

“Looks similar to nickel tailings in Sudbury, Ontario, much like the images shot by Edward Burtynsky. Improper chemical waste is an on-going environmental issue, which definitely needs more exposure.” Brittney Hopson, Facebook.

“Enhanced satellite imagery of a desert area, showing buried aquifer formations which are potential water supplies, GPR perhaps.”  John Munsey, Facebook.

“To me it looks like it is hot lava with the gases swirling with smoke…Iceland…or Hawaii?  Alison Renee Heller, Facebook.

Thanks to all of you for puzzling away with us in 2013. We had a lot of fun looking at satellite imagery, and we hope you did as well. (Missed one of our 2013 puzzlers? We’ve tagged them here.) Looking forward, the puzzler will be back and even more puzzling in 2014. We’ll see you then.

gulfstream_tir_2013099gulfstream_tir_2013099_palette

chile_tmo_2013267_crop_spanish
Las imágenes de satélite son como los mapas: están llenas de información útil e interesante, siempre y cuando tengas una clave. Éstas nos pueden mostrar cuánto ha cambiado una ciudad, cuán bien están creciendo nuestros cultivos, dónde arde un fuego o cuando se acerca una tormenta. Para revelar la riqueza de información en una imagen de satélite haz lo siguiente:

1. Busca una escala
2. Busca patrones, formas y texturas
3. Define los colores (incluyendo las sombras)
4. Encuentra el norte
5. Considera tu conocimiento previo

Estos consejos provienen de escritores y visualizadores de NASA Earth Observatory que los utilizan diariamente para interpretar imágenes de satélite. Te ayudarán a orientarte lo suficiente para extraer información valiosa de imágenes de satélite.

Leer más en español.

Este artículo originalmente fue publicado en inglés en NASA Earth Observatory. Traducción al español de Laura Delgado López, IGES.

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