Fortresses, farmlands of the Maya emerge from massive LiDAR survey

Enlarge (credit: 21st Century Fox ) A recent aerial survey revealed thousands of ancient Maya structures previously hidden beneath the dense Guatemalan jungle, including houses, irrigation canals, fortifications, and even a pyramid. More importantly, though, the survey of 2000 square kilometers of northeastern Guatemala provides a bird’s-eye view of the landscape of ancient Maya cities, farms, and highways. That big picture view of the Maya is letting archaeologists ask bigger questions about this still-enigmatic civilization. A sense of mystery still surrounds the Maya, mostly because so much of their once powerful and sophisticated society now lies hidden beneath thick tropical foliage. In recent years, archaeologists have started using lasers to peer beneath the thick canopy of leaves and map the ancient Maya landscape from above. They’re using a technology called “light detection and ranging,” or LiDAR, which maps the height of features on the ground by measuring how long it takes infrared light beamed down from a plane to bounce off those structures and return to the instrument. Using a plane lets surveyors cover a lot of ground in a short time, and one recent survey covered the largest area so far. The results hint that Maya civilization may have been more extensive and more densely populated than archaeologists realized. The survey, funded by the nonprofit Pacunam foundation, covered 2000 square kilometers of northeastern Guatemala in 2016. Archaeologists have been poring over the data since early 2017, and they say they’ve discovered over 60,000 new structures, from irrigation canals and highways to fortresses and pyramids. Read 16 remaining paragraphs | Comments

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Fortresses, farmlands of the Maya emerge from massive LiDAR survey

Keck Observatory’s exoplanet imager captures its first photos

The W.M. Keck Observatory’s near infrared camera has a new instrument that gives it the power to capture images of Jupiter-sized exoplanets near their stars. That instrument is a vortex coronagraph , and it has recently taken its first two photos. One of them (top left) is a photo of the innermost of three dust discs surrounding a young star 380 light-years away. When the Jet Propulsion Laboratory team who published the study about the image combined the coronagraph’s data with Spitzer telescope’s and NASA’s WISE mission’s , they were able to conclude that the disc is made up of pebble-sized grains of olivine. That’s one of the most common silicates on Earth. The other (top right) is a brown dwarf — a celestial body bigger than the biggest gas giants but smaller than the smallest stars — that’s 23 times as far from its host star than the Earth is from the sun. Keck’s instrument was able to spot the brown dwarf despite its star’s brilliance, because coronagraphs are designed to filter out starlight. This particular one is special, though: it doesn’t block starlight with “masks” like other coronagraphs do. Instead, it redirects light by combining and cancelling out light waves. Now that JPL scientists have proven that the instrument works, they plan to continue using it to observe young stars that could have exoplanets in the future. Dmitri Mawet, the JPL scientist who led the study about the brown dwarf image, explains: “The vortex coronagraph allows us to peer into the regions around stars where giant planets like Jupiter and Saturn supposedly form. Before now, we were only able to image gas giants that are born much farther out. With the vortex, we will be able to see planets orbiting as close to their stars as Jupiter is to our sun, or about two to three times closer than what was possible before.” Source: NASA

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Keck Observatory’s exoplanet imager captures its first photos