'A Flawless Point'. The photograph shows the Milky Way arching over Yosemite Valley in California’s famous national park. A lens-shaped (lenticular) cloud hovers over the distinct granite dome of Liberty Cap, which rises to an elevation of over 2000m, near the centre of the photograph (Rogelio Bernal Andreo)
Observations using the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed an unexpected spiral structure in the material around the old star “R Sculptoris.” This feature has never been seen before and is probably caused by a hidden companion star orbiting the star. This slice through the new ALMA data reveals the shell around the star, which shows up as the outer circular ring, as well as a very clear spiral structure in the inner material.
ALMA (ESO/NAOJ/NRAO)/M. Maercker et al.
ASU grad student discovers new form of lava flow on Mars - April 26, 2012
High-resolution photos of lava flows on Mars reveal coiling spiral patterns that resemble snail or nautilus shells. Such patterns have been found in a few locations on Earth, but never before on Mars. The discovery, made by Arizona State University graduate student Andrew Ryan, is announced in a paper published April 27, 2012, in the scientific journal Science.
In the past, a few scientists have argued that the plates in Elysium are in fact underlain by water ice.
Assessing those claims that ice was present today beneath the lava plates drove Ryan to study the area. “My initial goal,” he says, “was to model the nighttime infrared temperatures of the plates. Then I became fascinated by the terrain lying between the plates and the high-centered polygonal patterns found there.” This led him to look closely at every available image of the region.
On Earth, lava coils can be found on the Big Island of Hawaii, mainly on the surface of ropey pahoehoe lava flows. They have also been seen in submarine lava flows near the Galapagos Rift on the Pacific Ocean floor.
As Ryan explains, “The coils form on flows where there’s a shear stress – where flows move past each other at different speeds or in different directions. Pieces of rubbery and plastic lava crust can either be peeled away and physically coiled up – or wrinkles in the lava’s thin crust can be twisted around.”
Similarly, he notes that scientists have documented the formation of rotated pieces of oceanic crust at mid-ocean ridge spreading centers. “Since the surface of active lava lakes, such as those on Hawaii, can have crustal activity like spreading centers do, it’s conceivable that lava coils may form there in a similar way, but at a smaller scale.”
The size of Martian lava coils came as a surprise. “On Mars the largest lava coil is 30 meters across – that’s 100 feet. That’s bigger than any known lava coils on Earth,” he says. Ryan and Christensen’s work has inventoried nearly 200 lava coils in the Cerberus Palus region alone.
Read article here
Image Credit: NASA/JPL-Caltech/UA
photo and comment by David Kingham:
“On Thursday afternoon I drove 5 hours to meet up with Jason Hatfield and Mike Berenson in South Dakota. Our target was in Custer State Park on the Needles Highway, after driving past this rock formation called ‘The Eye of the Needle’ this past summer I knew I had to come back to photograph it at night. But it needed to be something special[…]”
- 2012 Geminid Meteor Shower (Video) (wjla.com)
- Watch the Geminid Meteor Shower Live online (wtkr.com)
- More Incredible Geminid Meteor Shower Images and Video (universetoday.com)
Dreaming Matterhorn - Photo and comment by Mario Spalla:
Alone in the dark, one wonderful night in tent at 2.800mt in the Swiss Alps, near the Riffelsee, under a bright summer sky!
Paradox - (Image - Adam Cole / NPR) Sun Goes Down. Up Comes A Mystery by ROBERT KRULWICH Here’s a question you probably didn’t know was a question: Why is the sky dark at night? My daughter asked me this about 10 years ago. We were looking up at the night sky, and she said, “There’s lots of stars up there.” And I said, “Yes.” Then she said, “Are there stars everywhere?” And I said there were. Then she said, “Well, if there are stars everywhere, all of them shining, why don’t they fill the sky and make the sky shiny?” In her mind, the sky, instead of being dark, should look like this, brightness everywhere. MORE: http://www.npr.org/blogs/krulwich/2012/10/10/162630285/sun-goes-down-up-comes-a-mystery
Trail to the Milkyway - Mengzhonghua
This picture was taken at the top of Loveland Pass which is the highest mountain pass in the world that regularly stays open during a snowy winter season.
Venus-Jupiter Close Conjunction, by Laurent Laveder (France)