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Member since: Tue Feb 10, 2004, 12:08 PM
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Environmental Scientist

Journal Archives

Ganymede, biggest moon in the solar system, has a saltwater ocean

NASA says new observations from the Hubble Space Telescope confirm the existence of a salty subsurface ocean on Ganymede, the largest moon in the solar system, which orbits our largest neighbor planet, Jupiter.

The ocean is estimated to be about 60 miles thick -- 10 times deeper than the Mariana Trench, the deepest part of the Pacific -- but is buried under a layer of mostly icy crust 95 miles thick. Ganymede joins other neighborhood moons like Enceladus, the asteroid belt dwarf planet Ceres, and Saturn's Europa and Titan that host strange icy or liquid layers, making them prime targets in the search for life beyond Earth.

Scientists have hypothesized for decades that Ganymede might harbor an icy or even liquid ocean beneath its frigid surface. The key to confirming the presence of a saltwater ocean came from observing Ganymede's aurorae, which would look bright red to a human able to stand on the surface of the moon and gaze up through its thin oxygen atmosphere. But don't get too excited, it's much too thin to support life as we know it.

Auroral phenomena -- think the bright northern lights of the aurora borealis or the aurora australis down south -- are not fully understood, but are linked to magnetic fields interacting with the solar wind. Ganymede is the only moon in the solar system that generates its own magnetic field thanks to its liquid iron core, but it also lies within the magnetic field of massive Jupiter. As Jupiter's magnetic field changes, it affects the aurorae on Ganymede, causing them to "rock back and forth" according to Joachim Saur, a professor for geophysics at the University of Cologne, who presented the news on a NASA teleconference Thursday.



Non-invasive ultrasound restores memory in Alzheimer's mice

A potential method of treating Alzheimer's disease using ultrasound is being hailed as a "breakthrough."

A team of researchers at the University of Queensland's Queensland Brain Institute Clem Jones Centre for Ageing Dementia Research have successfully restored memory function in mice using the drug-free, non-invasive technology to break down the neurotoxic amyloid plaques that cause memory loss and loss of cognitive function.

"We're extremely excited by this innovation of treating Alzheimer's without using drug therapeutics," said CJCADR director Professor Jürgen Götz.

"The word 'breakthrough' is often misused, but in this case I think this really does fundamentally change our understanding of how to treat this disease, and I foresee a great future for this approach."

To test the treatment, first the team deposited amyloid-β into the brains of the test mice -- the peptide that has been implicated with effecting Alzheimer's dementia. This creates a mouse model of the disease that can be used to test treatments.



Star cluster NGC 6193 and nebula NGC 6188 (Big Space Image)

This image, taken by OmegaCAM on the VLT Survey Telescope at Paranal Observatory, shows a section of the Ara OB1 stellar association. In the centre of the image is the young open cluster NGC 6193, and to the right is the emission nebula NGC 6188, illuminated by the ionising radiation emitted by the brightest nearby stars.

Thursday TOON Roundup 4- The Rest







Thursday TOON Roundup 3- Clintons

Thursday Toon Roundup 2- Haters

Thursday Toon Roundup 1- Letter Treason

Enceladus may have ocean with the right ingredients for life, scientists say

Scientists say they’ve discovered evidence of a watery ocean with warm spots hiding beneath the surface of Saturn’s icy moon Enceladus. The findings, described in the journal Nature, are the first signs of hydrothermal activity on another world outside of Earth – and raise the chances that Enceladus has the potential to host microbial life.

Scientists have wondered about what lies within Enceladus at least since NASA’s Cassini spacecraft caught the moon spewing salty water vapor out from cracks in its frozen surface. Last year, a study of its gravitational field hinted at a 10-kilometer-thick regional ocean around the south pole lying under an ice crust some 30 to 40 kilometers deep.

Another hint also emerged about a decade ago, when Cassini discovered tiny dust particles escaping Saturn’s system that were nanometer-sized and rich in silicon.

“It’s a peculiar thing to find particles enriched with silicon,” said lead author Hsiang-Wen Hsu, a planetary scientist at the University of Colorado, Boulder. In Saturn’s moons and among its rings, water ice dominates, so these odd particles clearly stood out.


Sun emits X2.2-class Flare

Sun Emits an X2.2 Flare on March 11, 2015
The sun emitted a significant solar flare, peaking at 12:22 p.m. EDT on March 11, 2015. NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel.

This flare is classified as an X2.2-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.


Sol, that's so rude!

Outburst on the Sun
The Sun blew out a coronal mass ejection along with part of a solar filament over a three-hour period (Feb. 24, 2015). While some of the strands fell back into the Sun, a substantial part raced into space in a bright cloud of particles (as observed by the SOHO spacecraft). The activity was captured in a wavelength of extreme ultraviolet light. Because this occurred way over near the edge of the Sun, it was unlikely to have any effect on Earth.

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