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.
Este artículo originalmente fue publicado en inglés en NASA Earth Observatory. Traducción al español de Laura Delgado López, IGES.
Every month we offer a puzzling satellite image here on Earth Matters. Every month someone seems to figure it out quickly. We are feeling like it is time to throw down some gauntlets.
The December 2013 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.
It’s that Time of Year
Monarch butterflies congregate in central Mexico every winter. Sandhill cranes stop at a small section of the Platte River in Nebraska every spring. And earth and planetary scientists congregate in San Francisco each December.
More than ten thousand people converged on Moscone Center this week for the the fall meeting of the American Geophysical Union, a hectic five-day event full of lectures, poster presentations, networking lunches, press conferences, and plenty of coffee and beer. For updates from the meeting, check out Dave Petley at the Landslide blog, Will Morgan at Polluting the Internet, the Barometer Podcast, Real Climate, and Journeys of Dr. G from Laura Guretin.
Tracking Tornado Intensity
Are tornadoes getting stronger? It’s a complicated and controversial topic among meteorologists, but Florida State University’s James Elsner thinks the answer is probably yes (with an emphasis on probably). Elsner came to that conclusion after analyzing the damage caused by every tornado to hit between 1994 and 2006. “If I were a betting man, I’d say tornadoes are getting stronger,” he noted during a talk the American Geophysical Union meeting this week. But when asked directly at a press conference whether they were, he resorted to caveats, according to Scientific American. “I’m not doing this [work] to establish the future intensity of tornadoes,” he explained, but to establish a method that someday could indeed determine if the storms are becoming more powerful. For more on the muddled topic of tornado intensity trends, see this detailed post from DotEarth’s Andrew Revkin.
Arctic Cyclones Galore
Remember that strong Arctic storm that whirled near the north pole back in the summer of 2012? A new analysis shows that there are more of them than we thought—40 percent more. From 2000 to 2010, about 1,900 cyclones churned across the top of the world each year, leaving warm water and air in their wakes—and melting sea ice in the Arctic Ocean. “We now know there were more cyclones than previously thought, simply because we’ve gotten better at detecting them,” one of the authors explained. “We can’t yet tell if the number of cyclones is increasing or decreasing, because that would take a multidecade view.” Read the press release.
Data Visualization AMA
If you missed the Reddit Ask Me Anything with Earth Observatory art director Robert Simmon, you can find the transcript here.
We post items every day to facebook (and not everything that goes onto Facebook makes it onto our site). One of the highlights this week was a spectacular montage of astronaut photography put together by film student David Peterson. Look for Don Pettit’s head peering out from the cupola at the end end of the video. If you’re anything like me, you’ll find yourself watching it again. And again. And again.
Happy 15th Birthday, International Space Station! The first International Space Station component, the Russian Zarya module, was launched in November 1998. In the years since, NASA and its global partners have built a world-class orbiting laboratory and kept a continuous human presence in space since 2000.
I decided to celebrate the occasion by searching through the astronaut photography collection on Visible Earth to find of my 15 favorites. My goal was to find at least one image for each year dating back to 2000, though I couldn’t resist adding a few extras for some years. I also checked our web traffic statistics to see how well my tastes matched with our readers. In a some cases, my favorites were also popular. In other cases, not so much. (Any other fans of crepuscular rays out there?)
But enough about me. What do you think? In the comments section, please send us the links to your favorite astronaut photographs from the ISS. However, we’d prefer if you send no more than three. And don’t forget to scroll to the bottom of this post for a list of the 15 most popular astronaut photographs on our site.
Earth Observatory’s 15 Most Popular Astronaut Photographs (based on website statistics since 2010)
1. Iberian Peninsula at Night
2. Montreal at Night
3. Nile River Delta at Night
4. India-Pakistan Borderlands at Night
5. Fire in the Sky and on the Ground
6. Midwestern USA at Night with Aurora Borealis
7. Las Vegas at Night
8. Liège at Night
9. Sarychev Peak Eruption, Kuril Islands
10. Northwestern Europe at Night
11. Mount Tambora Volcano, Sumbawa Island, Indonesia
12. Elusive Sprite Captured from the International Space Station
13. Looking Down on a Shooting Star
14. Atafu Atoll, Tokelau, Southern Pacific Ocean
15. Hurricane Earl – The Astronaut View
Last week, a city-state sized chunk of ice broke off of Pine Island Glacier (PIG), sending iceberg B-31 into a bay off West Antarctica. Though the formation of the 700 square-kilometer iceberg could be a purely natural event — the result of a floating ice tongue growing too long and losing its balance on the sea — some scientists suspect that changes in Pine Island Glacier are due to changing conditions below.
Five years ago this week, another block of ice broke off of the Antarctic Peninsula (radar image above from November 26, 2008). The seaward edge of Wilkins Ice Shelf spent much of 2008 breaking loose from the continent. Unlike PIG, Wilkins shattered and splintered into much smaller bits. And in that case, few doubted that global warming — or at least warming of the Antarctic Peninsula — played a major role.
NASA satellites are still tracking the last week’s PIG offspring. Check out these images from:
Each month, Earth Observatory offers up a puzzling satellite image here on Earth Matters. The November 2013 puzzler is above. Your challenge is to use the comments section to tell us 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 300 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 for being the first to respond or for digging up the most interesting kernels of information. 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, 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 this time.
Agony in the Philippines
Satellite images of Super Typhoon approaching and smashing into the Philippines last week were extremely worrisome. Reports and imagery from the ground have now confirmed that the concern was justified. One of the most intense tropical cyclones ever measured by satellites has left the Philippines in chaos. The Capital Weather Gang has heartbreaking footage from Earth UncutTV, which had videographers working in the path of the storm.
Deadly Cyclone over Somalia
Scores of people have died in Somalia after another powerful tropical cyclone — known as 03A — slammed into the northeastern part of the country. According to Accuweather, about 1-2 tropical cyclones form in the Arabian Sea each year, often in November. The last cyclone to strike Somalia made landfall in December 2012. Read more about the storm from Voice of America and Gulf Today.
Super Typhoon Haiyan and Climate Change
Given the strength and destruction of Haiyan, it was inevitable for discussions to arise about the relationship between the most powerful tropical cyclones and climate change. Climate Central contacted some of the leading researchers in the field and detailed some of the complexities in this piece. Though not all experts agree, the general consensus is that warming will bring stronger, wetter, but less frequent storms in the coming decades. Read our feature about storms and climate change for more insight on this complicated balance.
New Clues about Chelyabinsk Meteor
Following the dramatic meteor explosion over Chelyabinsk on February 15, 2013, eye-popping video and photographs flooded social media. After the event, there was no shortage of speculation about the trajectory of the meteor and how the explosion created so much damage. Scientists have since had time to carefully review all of the available evidence and have just published a detailed analysis of the event in the journal Science. Read more about the new research from NASA Ames and check out this blog about one of the researchers who co-authored the study.
Tiger Stripes Beneath Antarctic Ice
A new study published in Science points out that stripes of dirt and rock beneath Antarctic glaciers create friction zones that slow the flow of ice toward the sea. The researchers focused on the Pine Island and Thwaites glaciers, which together have contributed about 10 percent of the world’s observed sea-level rise over the past 20 years. Read more about the research in this press release from Princeton.
From Facebook: Eclipse at 44,000 Feet
Flying at 44,000 feet (13,000 meters), eclipse chasers on a chartered jet managed to intercept the Moon’s shadow over the Atlantic Ocean during the November 3, 2013, solar eclipse. The remarkable flight made a perpendicular crossing of the central shadow track. The photograph below was taken by Ben Cooper of Launch Photography. See another unique view—from space—of the same eclipse here.
Following their successful “Let It Snow” photo contest, our colleagues at the soon-to-launch Global Precipitation Measurement (GPM) mission are looking for your best photos and videos of rain, sleet, hail, snow and any other precipitation. They describe their “Unique Perspectives” contest this way:
There are many ways to view precipitation…We’d like to see weather from all angles — far away, up close, above, below and inside. The more creative and unique, the better. Post your coolest photos and videos of precipitation from unique perspectives, and we’ll choose the best ones to post on the NASA Precipitation Measurement Missions websites…Winning photos will be selected by a group of judges comprised of NASA scientists and outreach personnel, and will be judged based on their creativity and artistic merit.
The new contest runs from November 1 to December 1, 2013, and imagery can be submitted via Flickr, Instagram, or Vimeo. Learn more about the contest and rules by visiting: http://pmm.nasa.gov/unique-perspectives
Engineer and avid traveler Andrew Bossi had one of the winning entries last spring – this shot of the harbor in Kulusuk, Greenland. His shot became part of an Image of the Day on Earth Observatory.
In between combing your photo archives and setting up your tripod for the perfect precipitation shot, check out this quirky anime cartoon about GPM from the science and outreach team at JAXA, NASA’s partner in the mission. If you don’t speak Japanese, turn on the closed-caption button.
Hindus are celebrating Diwali this week. That means cities and towns around the world—but particularly in South Asia—are ablaze with lamps, candles, and firecrackers. It’s also become a tradition (of sorts) to share a colorful image via social media that was supposedly taken by a satellite during Diwali. If that image turns up on your feed, be skeptical.
As we pointed out last year, that image is a composite created and colored back in 2003 by NOAA scientists to illustrate population growth over time. In reality, India during Diwali looks something more like the image you see at the bottom of this page. The fact is that any extra light produced during Diwali would be so subtle that it would be extremely difficult to detect from space.
The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite collected the data that was used to make the image below on November 12, 2012. Read more about the fake Diwali image from Earthsky or USA Today.
Congratulations to Jaimen W. for solving the October Puzzler the fastest. The answer is Chile’s Lluta River. See the Image of the Day that we published on November 1, 2013, for details about the area. Phil Echelman was right on Jaimen’s heels, responding with the correct answer just two minutes after Jaimen. Congratulations also to Javier Canete, Alan W, and Juan Pablo Joui for offering interesting information about the area.
The unique perspective—and beauty—of satellite imagery never ceases to fascinate me. In this case, the satellite perspective of Lluta River does a remarkable job of illustrating how constricted and precious water and farmland is in this extremely arid region. But distance also blurs detail. I was curious about what this river valley looked like from the ground, so I did some searching on Panoramio and Flickr. I’ve included two of the many shots I came across at the top and bottom of this post. The panorama at the top was taken by Gustavo Canales; Julie Laurent took the photograph at the bottom.
While researching the Lluta, I ended up in touch with Pablo Pastén González, an engineer at Northwestern University and the Pontifical Catholic University of Chile. His group has been studying the Lluta since 2007. Via email, he shared some thoughts about what he finds most notable about the river.
“The interplay between the Atacama aridity, the presence of ancestral communities, high arsenic and boron concentrations in the fluvial network deriving from the complex interaction of hydrodynamic and biogeochemical factors, with natural (geothermal) and anthropogenic (legacy mining) sources upstream from the place of your picture makes it a prime spot for research in the geosciences. At the same time, the presence of ancestral cultures, the proximity of the border with Perú, and the push from the Chilean government to increase economic activity (mining, agriculture, tourism) makes it a fascinating place where science meets economic development and policy.
For example, not far upstream from the place of your picture, the Chilean government is planning to build the Chironta dam, a reservoir that seeks water storage for irrigation and flood control during the “Bolivian winter,” the wet season between December and March. What’s puzzling is that the Lluta brings high concentrations of arsenic-loaded particles that will probably make the sediments of this dam into an arsenic reservoir. We expect that the dam will work as a giant settling basin that will decrease the concentration of total arsenic flowing downstream (i.e. less arsenic will flow through the reach in your picture), but an arsenic time bomb that could be set off by the wrong biogeochemical/hydraulic conditions in the dam.”