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The destructive power of a hurricane appears to be good news for mangroves in the Florida Everglades. When Category 3 hurricanes Wilma (2005) and Irma (2017) struck Florida, mangroves took a beating, especially along the state's western coast. Many trees lost their canopies, others snapped or were uprooted. Yet more were submerged by storm surge. But the storm surge also deposited phosphorus-rich mineral sediment from the ocean floor atop mangrove soils. The sediment increased soil phosphorus concentrations, fueling mangrove regeneration and recovery, according to a study by researchers at Florida International University and other institutions. The results are published in the journal Proceedings of the National Academy of Sciences. "When you hear about hurricanes, it's usually about negative impacts to the coastal landscape because of infrastructure damage and ecosystem damage," said Edward Castañeda, an FIU researcher and the study's lead author. "But when you dig into information going back 20 years, you realize there's a positive side to these storms." With data from the Florida Coastal Everglades Long-Term Ecological Research site funded by the National Science Foundation, Castañeda and his colleagues came to the conclusion that hurricanes help mangroves increase soil elevation, and branch out and find new homes when seeds are scattered. Mangrove forests are important parts of the Florida coastal ecosystem. They blunt the impact of hurricanes, scientists have found. They absorb damaging winds and prevent floodwaters from flowing farther inland. They store carbon that otherwise would be released into the atmosphere, and provide nurseries for fish, crab, shrimp and mollusk species that are critical in Florida's commercial and recreational fishing industries. "This study demonstrates the importance of a long-term perspective when assessing the impacts of large, intense disturbances such as hurricanes," says John Schade, a program director in NSF's Division of Environmental Biology. "What seems like a destructive force can be an affirmation of new life when we look back from the perspective of time."
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A mere 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth. Also known as NGC 5128, the peculiar elliptical galaxy is over 60,000 light-years across. A region spanning about 8,500 light-years, including the galaxy's center (upper left), is framed in this sharp Hubble Space telescope close-up. Centaurus A is apparently the result of a collision of two otherwise normal galaxies resulting in a violent jumble of star forming regions, massive star clusters, and imposing dark dust lanes. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black hole with a billion times the mass of the Sun. As in other active galaxies, that process likely generates the radio, X-ray, and gamma-ray energy radiated by Centaurus A.
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The silhouette of an intriguing dark nebula inhabits this cosmic scene. Lynds' Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only visible in long telescopic exposures of the region. In contrast, the brighter reflection nebula vdB 62 is more easily seen, just above and right of center. LDN 1622 lies near the plane of our Milky Way Galaxy, close on the sky to Barnard's Loop, a large cloud surrounding the rich complex of emission nebulae found in the Belt and Sword of Orion. With swept-back outlines, the obscuring dust of LDN 1622 is thought to lie at a similar distance, perhaps 1,500 light-years away. At that distance, this 1 degree wide field of view would span about 30 light-years. Young stars do lie hidden within the dark expanse and have been revealed in Spitzer Space telescope infrared images. Still, the foreboding visual appearance of LDN 1622 inspires its popular name, the Boogeyman Nebula.
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© Joshua CrippsNikon Z 7 in DX crop mode, with the AF-S NIKKOR 200-500mm f/5.6E ED VR lens attached using the Mount Adapter FTZ. Focal length at 500mm Photo by: 750mm equivalent in DX mode We spoke with Joshua Cripps about an image he created during an annular solar eclipse in the Dubai desert. He was already going to be in the Middle East in mid-December 2019 and when he found out there would be an annular solar eclipse and he decided to extend his trip to photograph it. Joshua says he spent a “crazy amount of planning” the shoot. He used the PhotoPills app to plan the location aspects of the shot including the shooting position he would be in as well as the position of the man and camel. He says, “Ultimately [what] made my decision was the sun’s height at totality. From the UAE, the sun would only be about 6° above the horizon during totality. This meant it would be far easier to get a subject into the shot with the eclipse.” Once he knew where he wanted to be for the eclipse, Joshua says, “The next step was determining what that subject should be. Since the path of totality swept right through the Empty Quarter, an endless expanse of sand dunes, I wanted something representative of that region and landscape. I came up with a list of possible subjects, including Arabian horses, camels, falcons, and Arabian oryxes.” He eventually settled on a camel—being a domesticated animal—as it allowed him more control along with the farmer. Joshua says that finding a suitable spot for the camel and farmer to stand was tedious. “That process was painstaking because I had a very specific vision for how I wanted the shot to turn out: I wanted the camel and the man standing on a sand dune encircled by the eclipse. He planned everything down to the specific GPS coordinates for where he would be standing to shoot and the spot for the subjects. The location where the image was created was about seven kilometers from Tal Moreeb, near the Liwa Oasis in the Empty Quarter desert. Tal Moreeb is one of the highest sand dunes in the world and is found in the United Arab Emirates. “In order to have this specific proportion between the size of the camel and the size of the sun we h
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, , Hubble, ESO, Amateur Data; Processing & Copyright: Robert Gendler Explanation: A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, spans over 300 light-years, one of our galaxy's largest star forming regions. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye, though at a distance of 7,500 light-years it is some 5 times farther away. This gorgeous telescopic close-up reveals remarkable details of the region's central glowing filaments of interstellar gas and obscuring cosmic dust clouds in a field of view nearly 20 light-years across. The Carina Nebula is home to young, extremely massive stars, including the still enigmatic and violently variable Eta Carinae, a star system with well over 100 times the mass of the Sun. In the processed composite of space and ground-based image data a dusty, two-lobed Homunculus Nebula appears to surround Eta Carinae itself just below and left of center. While Eta Carinae is likely on the verge of a supernova explosion, X-ray images indicate that the Great Carina Nebula has been a veritable supernova factory.
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