Several brittle stars have their arms wrapped around the branches of an octocorallian sea fan, family Plexauridae, at 1,120 m(3,675 ft) depth in Exuma Sound, in the Bahamas.
Image courtesy of Bahamas Deep-Sea Coral Expedition Science Party, NOAA-OE.
(via: NOAA Ocean Explorer)
The tentacles of a box jellyfish (Chironex fleckeri) trail behind it and can reach 15 feet (4.6 meters) in length. Found in northern Australia and adjacent waters, a sting from this species can be deadly. This species of box jellyfish, the largest, can have as many as 60 tentacles.
Photograph by David Doubilet, National Geographic.
Mars - Ismeniae Fossae
This scene shows a section of Ismeniae Fossae that straddles the southern highlands–northern lowlands of Mars. The 2 km-wide curvilinear trough that runs through this image contains numerous parallel grooves and ridges comprising material from the trough walls and material that has been dragged along the floor by ancient glaciers and ice-rich flows.
In the left portion of the scene the channel truncates a roughly 25 km-wide crater. Material in the crater walls has slumped down into the channel, smoothing over the grooved floor. Around this crater, and elsewhere in Ismeniae Fossae, clusters of circular to elliptical, partially interconnected depressions are observed. These may be either secondary impact craters from debris flung out by larger impact craters, or collapse pits caused by the sublimation of subsurface ice…
Image: ESA/DLR/FU Berlin (G. Neukum) [high-resolution]
(read more: Wired Science)
What Doomed the Stromatolites? - Scientists find key clue to an ancient enigma
by Cherie Winner
About a billion years before the dinosaurs became extinct, stromatolites roamed the Earth until they mysteriously disappeared. Well, not roamed exactly.
Stromatolites (“layered rocks”) are rocky structures made by photosynthetic cyanobacteria. The microbes secrete sticky compounds that bind together sediment grains, creating a mineral “microfabric” that accumulates in fine layers. Massive formations of stromatolites showed up along shorelines all over the world about 3.5 billion years ago. They were the earliest visible manifestation of life on Earth and dominated the scene for more than two billion years.
“They were one of the earliest examples of the intimate connection between biology—living things—and geology—the structure of the Earth itself,” said Joan Bernhard, a geobiologist at Woods Hole Oceanographic Institution (WHOI). “Then, around one billion years ago, their diversity and abundance begin to take a nosedive.” …
(read more: Oceanus - WHOI)
Coelacanths might be monogamous, to the surprise of researchers
by Cynthia McKelvey
They evaded humans for millions of years and live very private lives. The hulking, fleshy-finned fish known as the coelacanth has beguiled scientists for generations. But the coelacanth mystique that enchants researchers also makes it difficult to study. Researchers recently revealed in Nature Communications one startling aspect of the coelacanth lifestyle: they might be monogamous.
Presumed extinct for over 60 million years, the coelacanth (SEE-lah-kanth) was known only in fossil form until a fisherman caught a live one in 1938 near South Africa. Recently, scientists have found populations of dozens of coelacanths nestled in caves hundreds of meters deep in the Indian Ocean near Kenya, Tanzania and the Comoros Islands.
Monogamy poses a risk to coelacanths in part because of the onerous three-year-long pregnancies in females. The babies are fully developed when they’re born, but the mother sacrifices a lot of energy and is more vulnerable to predators while she carries her young. If one male with a bad set of genes sires the brood, all the offspring can suffer—and those three years might be wasted…
(read more: MongaBay)
photos: Hans Fricke and Mark V. Erdmann
Requiem with a marginal dragonfly
book of hours, Bruges or Ghent 15th century.
Beinecke Rare Book and Manuscript Library, MS 287, fol. 161v
That’s a beaut dragonfly, even if it does seem to have an extra leg. But it was very clearly drawn from life and it makes me happy to think of some medieval stationer taking the time to look at and appreciate an insect.
Galactic Dust Clouds
Galactic Cirrus clouds billow and obscure the background Universe in this direction. NGC 7497 is seen through partly cloudy skies. These galactic clouds of dust are sculpted by the winds of nearby stars. They are relatively close to us (only hundreds of light years away) and there are few stars in the foreground to hinder of view of them. The color of the clouds is odd due to the fact they are illuminated mostly by diffuse galactic star light.
Image: Adam Block/Mount Lemmon SkyCenter/University of Arizona [high-resolution]
Caption: Adam Block
(via: Wired Science)
This cluster of stars is known as Messier 15, and is located some 35 000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years.
Both very hot blue stars and cooler golden stars can be seen swarming together in the image, becoming more concentrated towards the cluster’s bright centre. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core. As well as stars, Messier 15 was the first cluster known to host a planetary nebula, and it has been found to have a rare type of black hole at its centre.
This new image is made up of observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum.
Image: NASA, ESA [high-resolution]
Caption: Hubble Heritage Team
(via: Wired Science)