It's not the work of aliens. Instead, you can chalk these crop circles up to humans + money + time. And, with the help of satellite imaging, you can watch as humans use money to change the desert over the course of almost 30 years.
Landsat is a United States satellite program that's been in operation since 1972. Eight different satellites (three of them still up there and functioning) have gathered images from all over the world for decades. This data is used to help scientists studying agriculture, geology, and forestry. It's also been used for surveillance and disaster relief.
Now, at Google, you can look at images taken from eight different sites between 1984 and 2012 and and watch as people change the face of the planet. In one set of images, you can watch agriculture emerge from the deserts of Saudi Arabia — little green polka-dots of irrigation popping up against a vast swath of tan. In another se, you'll see the deforestation of the Amazon. A third, the growth of Las Vegas. It's a fascinating view of how we shape the world around us, in massive ways, over a relatively short period of time.
The images above — prepared by NASA hurricane researcher Owen Kelly — were taken on Sunday, before Hurricane Sandy made landfall on the United States' Northeast coast. They're made from radar data collected by the Tropical Rainfall Measuring Mission (TRMM) satellite, and they show a feature of this storm that helps explain why it's caused much more destruction than you might expect from a Category 1 hurricane.
In the right-hand image, showing a close-up of the storm's eye, you can see a feature labeled "eyewall". Those are vertical cloud walls that surround the eye, and they're the spot with the strongest winds in the whole storm.
Placed in context, the TRMM-observed properties of Hurricane Sandy’s eyewall are evidence of remarkable vigor. Most hurricanes only have well-formed and compact eyewalls at category 3 strength or higher. Sandy was not only barely a category 1 hurricane, but Sandy was also experiencing strong wind shear, Sandy was going over ocean typically too cold to form hurricanes, and Sandy had been limping along as a marginal hurricane for several days.
That eyewall, says NASA and New Scientist, is the result of Sandy's Frankenstorm nature. Despite all the factors that should have made this storm weak, it represented the merging of several storm systems. Because of that, Sandy was stronger than a Category 1 storm normally is.
Read the full story on this at NASA and New Scientist
Via Michael Marshall
Today is the final day for voting in the USGS "Earth as Art" image project. To celebrate the 40th Anniversary of the Landsat Program on July 23, 2012, the federal agency seeks your help in selecting the 5 coolest images from more than 120 scenes.
For 40 years Landsat satellites have been acquiring images of the land cover of the planet. The satellites have given us spectacular views of mountains, valleys, coastal areas, islands, volcanic fields, forests, and patterns on the landscape. By highlighting some of those features and creatively crafting the colors we have developed a series of "Earth as Art" perspectives that reveal the artistic side of Landsat. The Top 5 "Earth as Art" images will be announced on July 23 in Washington, D.C., at a special event commemorating the launch of the first Landsat satellite.
Vote here, by end of day today.
Image above, from the Landsat collection: Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people.
(Thanks, Miles O'Brien!)
How? It's surprisingly simple. Turns out, demand for trees in neighborhoods behaves a lot like a luxury item, as opposed to a basic necessity.
Tim De Chant at The Per Square Mile blog wrote about research on this a couple of weeks ago. Then, he went out and found examples, using images from Google Earth.
Read the rest
You're familiar with contrails, the tracks left by airplanes as they move across the sky. Those are made when hot water vapor from the exhaust of jet engines hits cold, high-altitude air and condenses into ice.
Under the right conditions, big ships can leave a very similar trail, but it's caused by a slightly different mechanism. Incomplete combustion of fossil fuels means little particles of dust—aerosols—come out in the exhaust. Water molecules are attracted to these aerosols. As water builds up around a piece of dust, you get a cloud. Yes, it's basically cloud-seeding.
This photo of oceanic "contrails" over the Pacific is one of NASA's Images of the Day today, but it's not the first time they've featured this kind of photo. This is a cool phenomenon and they've posted photos of it in 2002, 2005, and 2009.
Thanks Philip Bump!
From satellites, to probes, to capsules full of people—humans have launched more than 7000 objects into space. In a nifty infographic at Technology Review, Tommy McCall and Mike Orcutt illustrate reams of data, collected from hundreds of sources, to show how the character of launches has changed over time in different countries.
One of the first things you'll notice when you look at the graphic: The Soviet Union launched far more objects into space than anybody else. Why? According to Orcutt, it's partly because Soviet satellites were less robust. The U.S. didn't have to launch as many because we got more mileage out of the ones we did launch.
Via David Brin