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Posts Tagged ‘science’

Pebbly Rocks Testify to Old Streambed On Mars


May 30, 2013 — Detailed analysis and review have borne out researchers’ initial interpretation of pebble-containing slabs that NASA’s Mars rover Curiosity investigated last year: They are part of an ancient streambed.

 

NASA’s Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named “Hottah” after Hottah Lake in Canada’s Northwest Territories. It may look like a broken sidewalk, but this geological feature on Mars is actually exposed bedrock made up of smaller fragments cemented together, or what geologists call a sedimentary conglomerate. Scientists theorize that the bedrock was disrupted in the past, giving it the titled angle, most likely via impacts from meteorites. (Credit: NASA/JPL-Caltech/MSSS)

The rocks are the first ever found on Mars that contain streambed gravels. The sizes and shapes of the gravels embedded in these conglomerate rocks — from the size of sand particles to the size of golf balls — enabled researchers to calculate the depth and speed of the water that once flowed at this location.

“We completed more rigorous quantification of the outcrops to characterize the size distribution and roundness of the pebbles and sand that make up these conglomerates,” said Rebecca Williams of the Planetary Science Institute, Tucson, Ariz., lead author of a report about them in the journal Science this week. “We ended up with a calculation in the same range as our initial estimate last fall. At a minimum, the stream was flowing at a speed equivalent to a walking pace — a meter, or three feet, per second — and it was ankle-deep to hip-deep.”

Read more: http://www.sciencedaily.com/releases/2013/05/130530150547.htm

Hubble Space Telescope Captures The Ring Nebula In Astonishing Detail


By Clay Dillow Posted 05.24.2013

The Ring Nebula
The Ring Nebula New images of the Ring Nebula captured by the Hubble Space Telescope are redefining the way astronomers understand its shape. NASA, ESA, C.R. Robert O’Dell (Vanderbilt University), G.J. Ferland (University of Kentucky), W.J. Henney and M. Peimbert (National Autonomous University of Mexico)
Astronomers love to point their telescopes at the Ring Nebula. Located 2,000 light years away in the constellation Lyra, this ring of glowing gas has a distinctive elliptical shape when seen from Earth. But new images captured by the Hubble Space Telescope suggest that the nebula actually looks a lot more like a football or a misshapen doughnut.

Giant storms on Saturn: Nasa captures incredible view of ‘rose’ hurricane 20 times bigger than any on Earth


  • Hurricane’s eye is about 1,250 miles (2,000 kilometers) wide, 20 times larger than the average hurricane eye on Earth
  • Hurricane swirls inside a large, mysterious, six-sided weather pattern known as the hexagon

By MARK PRIGG

PUBLISHED: 17:40 GMT, 29 April 2013 | UPDATED: 18:49 GMT, 29 April 2013

At first glance, it resembles a giant rose, surrounded by green foliage.

However, in fact this is a huge, violent storm of the surface of Saturn – and one that has been brewing for years

In high-resolution pictures and video, scientists say the hurricane’s eye is about 1,250 miles (2,000 kilometers) wide, 20 times larger than the average hurricane eye on Earth.

The spinning vortex of Saturn's north polar storm The spinning vortex of Saturn’s north polar storm resembles a deep red rose of giant proportions surrounded by green foliage in this false-color image from NASA’s Cassini spacecraft. Measurements have sized the eye at a staggering 1,250 miles (2,000 kilometers) across with cloud speeds as fast as 330 miles per hour (150 meters per second).
Nasa’s Cassini spacecraft has provided scientists the first close-up, visible-light views of a behemoth hurricane swirling around Saturn’s north pole.

Thin, bright clouds at the outer edge of the hurricane are traveling 330 mph(150 meters per second). The hurricane swirls inside a large, mysterious, six-sided weather pattern known as the hexagon.

‘We did a double take when we saw this vortex because it looks so much like a hurricane on Earth,’ said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena.

‘But there it is at Saturn, on a much larger scale, and it is somehow getting by on the small amounts of water vapor in Saturn’s hydrogen atmosphere.’

Scientists will be studying the hurricane to gain insight into hurricanes on Earth, which feed off warm ocean water.

Read more: http://www.dailymail.co.uk/sciencetech/article-2316699/The-breathtaking-rose-storms-Saturn-captured-Cassini.html#ixzz2S7oHC54E

Scientists Detect ‘Dark Lightning’ Energy Burst Linked to Visible Lightning

April 25, 2013 1 comment

Apr. 24, 2013 — Researchers have identified a burst of high-energy radiation known as ‘dark lightning” immediately preceding a flash of ordinary lightning. The new finding provides observational evidence that the two phenomena are connected, although the exact nature of the relationship between ordinary bright lightning and the dark variety is still unclear, the scientists said.

Three images, left to right, of the same thundercloud depict a less-than-10-milliseconds-long sequence of events: (left) formation within the cloud of a small channel, or ‘leader,’ of electrical conductivity (yellow line) with weak emission of radio signals (ripples), to (middle) a burst of both dark lightning (pink) and radio waves (larger ripples), to (right) a discharge of bright lightning and more radio waves. (Credit: Studio Gohde)

“Our results indicate that both these phenomena, dark and bright lightning, are intrinsic processes in the discharge of lightning,” said Nikolai Østgaard, who is a space scientist at the University of Bergen in Norway and led the research team.

He and his collaborators describe their findings in an article recently accepted in Geophysical Research Letters — a journal of the American Geophysical Union.

Dark lightning is a burst of gamma rays produced during thunderstorms by extremely fast moving electrons colliding with air molecules. Researchers refer to such a burst as a terrestrial gamma ray flash.

Read more:http://www.sciencedaily.com/releases/2013/04/130424210319.htm

Left vs. right


 

Curiosity Chills Out In Safe Mode While NASA Analyzes Computer Glitch


Corrupted files may be the fault of cosmic radiation.
By Rebecca Boyle Posted 03.04.2013
 
A Rover In Full

A Rover In Full NASA/JPL-Caltech

NASA’s Mars rover Curiosity paused its work over the weekend and is chilling in safe mode on Mars, while engineers on Earth try to resolve a computer glitch. The rover switched to a backup computer, but operations are on hiatus while NASA engineers work on the problem.

Last week, engineers noticed a glitch in the flash memory on one of the rover’s two computers. Curiosity had normal communications with Earth on Wednesday, Feb. 27, but like an annoying Facebook friend, it updated its status yet included no actual information. In the status update, engineers learned the rover did not go to sleep when planned, and when they started diagnosing the problem, they realized the main A-side computer had some corrupted files.

Read more: http://www.popsci.com/technology/article/2013-03/today-mars-curiosity-chills-safe-mode-while-nasa-analyzes-computer-glitch

NASA’s Van Allen Probes Reveal a New Radiation Belt Around Earth


Feb. 28, 2013 — NASA’s Van Allen Probes mission has discovered a previously unknown third radiation belt around Earth, revealing the existence of unexpected structures and processes within these hazardous regions of space.

Two giant swaths of radiation, known as the Van Allen Belts, surrounding Earth were discovered in 1958. In 2012, observations from the Van Allen Probes showed that a third belt can sometimes appear. The radiation is shown here in yellow, with green representing the spaces between the belts. (Credit: NASA/Van Allen Probes/Goddard Space Flight Center)

Previous observations of Earth’s Van Allen belts have long documented two distinct regions of trapped radiation surrounding our planet. Particle detection instruments aboard the twin Van Allen Probes, launched Aug. 30, quickly revealed to scientists the existence of this new, transient, third radiation belt.

The belts, named for their discoverer, James Van Allen, are critical regions for modern society, which is dependent on many space-based technologies. The Van Allen belts are affected by solar storms and space weather and can swell dramatically. When this occurs, they can pose dangers to communications and GPS satellites, as well as humans in space.

Read more: http://www.sciencedaily.com/releases/2013/02/130228155430.htm