Friday, 24 September 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

New Aurora Webcam Captures Spectacular Videos, Images

Posted: 22 Sep 2010 12:02 PM PDT

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The return of winter darkness and sub-zero temperatures comes with at least one bright side for residents of Northern Canada — the return of aurora borealis displays. Luckily for those of us living in southern latitudes, we too can now watch the show from the relative comfort of warmer climates.

The live webcam, called AuroraMax, was launched Sept. 20 by the Canadian Space Agency, in partnership with the University of Calgary and Astronomy North. The camera, located in Yellowknife, Northern Territories (right), shoots an 180-degree view of the sky, which produces a circular image.

The camera goes live between dusk and dawn, which is currently about 12 a.m. to 8 a.m. EST (or 5 a.m. to 1 p.m. GMT). The webcam will be live until May 2012.

The gallery above showcases the best displays captured so far.

Gallery Images and video: Canadian Space Agency/University of Calgary/Astronomy North.

Map: Google Maps

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Swirls and Whorls Shine in a Stellar Lagoon

Posted: 22 Sep 2010 09:45 AM PDT

Dust clouds in the luminous Lagoon Nebula swirl in harsh stellar winds in this new image from Hubble's Advanced Camera for Surveys.

The nebula's tranquil name contrasts starkly with the violent activity that sculpted it. Located 4 to 5 thousand light-years away in the constellation Sagittarius, the Lagoon Nebula is a vast stellar nursery 100 light-years across. Clouds of hydrogen gas are slowly collapsing to form new stars, whose bright ultraviolet light sets the surrounding gas aglow in shades of red.

The young stars' ultraviolet radiation also pushes and erodes the gas and dust around it, creating billowing cloud-like swirls. In the last 5 years, astronomers have also found that several of these young stars have shot out long tendrils of matter from their poles.

These jets, known as Herbig-Haro objects, are usually formed by young stars that are still surrounded by a disk of material that is slowly glomming onto the star. The finding provides strong support for astronomers' theories about star formation in such hydrogen-rich regions.

A sharp eye on a dark night can pick out the Lagoon Nebula as a faint gray patch in the Milky Way, but a telescope and filtering is needed to bring out the nebula's striking colors. In this image, light from glowing hydrogen is colored red, light from ionized nitrogen is shown in green and light through a yellow filter, interestingly, is colored blue. The blue-white flare at the upper-left of the image is scattered light from a bright star just outside the field of view.


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Antique Pressed Orchids Used as Climate Change Data

Posted: 22 Sep 2010 07:45 AM PDT

Plants picked by Victorian collectors up to 150 years ago are a valuable new source of data for ecologists seeking to understand how climate change will affect the timing of flowering plants.

Scientists have used the carefully labeled and dated specimens of the early spider orchid, Ophrys sphegodes, to examine the affect of spring temperatures on flowering. The flowers were collected between 1848 and 1958.

The results, published in Journal of Ecology Sept.21, found that for a 1.8 degree Fahrenheit increase in the spring temperature, the orchid flowered 6 days earlier.

The results are nearly identical to field observations collected between 1975 and 2006. The fact that the response to temperature changes has remained constant, despite accelerated temperature increases since the 1970s, lends support to the use of museum specimens for climate change studies.

"There is an enormous wealth of untapped information locked within our museums and herbaria that can contribute to our ability to predict the effects of future climate change on many plant species," ecologist Anthony Davy of the University of East Anglia, co-author of the study, said in a press release. "It may well be possible to extend similar principles to museum collections of insects and animals."

There are approximately 2.5 billion plant and animal specimens held in natural history collections in museums and herbaria. Some date back to the time of Linnaeus, who devised the system of naming plants and animals about 250 years ago.

Understanding how climate affects the timing of developmental and seasonal events for plants and animals — such as flowering, egg laying, or migration — is essential for predicting future impacts on individual species and ecosystems. The data required for these predictions must be gathered over a number of years, and little of it is available.

Images: 1) An herbarium sheet of the early spider orchid collected May 1, 1900./ K. Robbirt. 2) Early spider orchid.

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