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Mars Base

Asteroid's troughs suggest stunted planet - 0 views

phys.org/...id-troughs-stunted-planet.html

scibyte65 Vesta

shared by Mars Base on 27 Sep 12 - No Cached
  • Scientists have been trying to determine the origin of these unusual troughs since their discovery just last year
  • new analysis supports the notion that the troughs are faults that formed when a fellow asteroid smacked into Vesta's south pole. The research reinforces the claim that Vesta has a layered interior, a quality normally reserved for larger bodies, such as planets and large moons.
  • ggest of those troughs, named Divalia Fossa, surpasses the size of the Grand Canyon by spanning 465 kilometers (289 miles) long, 22 km (13.6 mi) wide and 5 km (3 mi) deep
  • ...20 more annotations...
  • The complexity of their formation can't be explained by simple collisions
  • New measurements
  • taken by NASA's Dawn spacecraft last year
  • indicate that a large collision could have created the asteroid's troughs
  • would only have been possible if the asteroid is differentiated – meaning that it has a core, mantle and crust
  • By saying it's differentiated, we're basically saying Vesta was a little planet trying to happen
  • previous research has found signs of igneous rock on Vesta, indicating that rock on Vesta's surface was once molten, a sign of differentiation
  • If the troughs are made possible by differentiation, then the cracks aren't just troughs, they're graben
  • graben is a dip in the surface that forms when two faults move apart from each other and the ground sinks into the widening gap
  • Vesta's troughs have many of the qualities of graben
  • observations indicate that Vesta is also unusually planet-like for an asteroid in that its mantle is ductile and can stretch under a lot of pressure
  • not yet fully convinced that Vesta's troughs are graben
  • There are other qualities of Vesta that could be clues to how the troughs formed
  • unlike the larger asteroid Ceres, Vesta is not classified as a dwarf planet because the large collision at its south pole knocked it out of its spherical shape
  • if Vesta has a mantle and core, that would mean it has qualities often reserved for planets, dwarf planets and moons—regardless of its shape
  • believes the south pole collision knocked Vesta into its current speedy rate of rotation about its axis of about once per 5.35 hours
  • may have caused the equator to bulge outward so far and so fast that the rotation caused the troughs, rather than the direct power of the impact
  • enigma why Vesta rotates so quickly
  • Dawn has already left to explore Ceres, so all the data it will retrieve on Vesta is in hand
  • scientists will continue to sort that data out and improve on computer simulations of Vesta's interior
Mars Base

Intraplate Quakes Signal Tectonic Breakup - Science News - 0 views

www.sciencenews.org/...quakes_signal_tectonic_breakup

scibyte65 TectonicPlate

shared by Mars Base on 27 Sep 12 - No Cached
  • The first April 11 quake unzipped four perpendicular faults one after another in less than two minutes
  • They continued to resonate around the globe, triggering big aftershocks as far away as Mexico, a third study finds.
  • the number of quakes of magnitude 5.5 or greater, located more than 1,500 kilometers from the April 11 quakes, went up nearly fivefold for six days afterward
  • ...6 more annotations...
  • Most giant quakes don’t trigger temblors so far away
  • The biggest
  • was a magnitude 7 in Baja California, about 22 hours afterward
  • the triggered quakes are well below magnitude 5
  • The difference, Pollitz says, lay in the strike-slip nature of the April 11 quakes
  • fault geometry allows the stress of a crustal movement to propagate much farther across the planet’s surface
Mars Base

Unusual Indian Ocean Earthquakes Hit at Tectonic Breakup: Scientific American - 0 views

www.scientificamerican.com/article.cfm

scibte65 TectonicPlate

shared by Mars Base on 27 Sep 12 - No Cached
  • According to prevailing theories of plate tectonics, the Indo-Australian plate began to deform internally about 10 million years ago
  • thrusting the Himalayas up and slowing India down
  • Most scientists think that the Australian portion forged ahead, creating twisting tensions
  • ...3 more annotations...
  • inferred the presence of these seismic stresses by modeling stress changes from shortly before the 2012 earthquakes
  • magnitude-9.1 tremor in 2004
  • and another quake in 2005 — probably triggered the 2012 event by adding to pent-up stresses in the plate’s middle region.
Mars Base

A Crescent Moon in the Martian Sky - 0 views

www.universetoday.com/...escent-moon-in-the-martian-sky

scibyte65 Curiosity

shared by Mars Base on 26 Sep 12 - No Cached
  • raw image taken on September 21 by Curiosity’s right Mastcam shows a daytime view of the Martian sky with a crescent-lit Phobos
  • image
  • is a crop of the original, contrast-enhanced and sharpened
  • ...2 more annotations...
  • 13-km-wide Phobos has been spotted several times before by Mars rovers
  • most recently during a solar transit on September 13 (sol 37)
Mars Base

Buddhist statue, discovered by Nazi expedition, is made of meteorite, new study reveals - 0 views

phys.org/...ue-nazi-meteorite-reveals.html

scibyte65 meteorite

shared by Mars Base on 27 Sep 12 - No Cached
  • a 1,000 year-old ancient Buddhist statue which was first recovered by a Nazi expedition in 1938 has been analysed by scientists and has been found to be carved from a meteorite
  • statue, known as the Iron Man, weighs 10kg and is believed to represent a stylistic hybrid between the Buddhist and pre-Buddhist Bon culture
  • discovered in 1938 by an expedition of German scientists
  • ...10 more annotations...
  • expedition was supported by Nazi SS Chief Heinrich Himmler and the entire expeditionary team were believed to have been SS members.
  • unknown how the statue was discovered
  • believed that the large swastika carved into the centre of the figure may have encouraged the team to take it back to Germany
  • only became available for study following an auction in 2007.
  • first team to study the origins of the statue
  • The team was able to classify it as an ataxite
  • a rare class of iron meteorite with high contents of nickel.
  • statue was chiseled from a fragment of the Chinga meteorite which crashed into the border areas between Mongolia and Siberia about 15,000 years ago
  • first debris was officially discovered in 1913 by gold prospectors
  • believe that this individual meteorite fragment was collected many centuries before
Mars Base

Sumatra quake was part of crustal plate breakup: Study shows huge jolt measured 8.7, ri... - 0 views

phys.org/...ake-crustal-plate-breakup.html

scibyte65 TectonicPlate

shared by Mars Base on 27 Sep 12 - No Cached
  • Seismologists have known for years that the Indo-Australian plate of Earth's crust is slowly breaking apart
  • quake was caused by at least four undersea fault ruptures
  • within a 2-minute, 40-second period
  • ...27 more annotations...
  • This is part of the messy business of breaking up a plate. … This is a geologic process
  • will take millions of years to form a new plate boundary
  • likely, it will take thousands of similar large quakes for that to happen."
  • All four faults
  • were strike-slip faults, meaning ground on one side of the fault moves horizontally past ground on the other side
  • great quake of last April 11 "is possibly the largest strike-slip earthquake ever seismically recorded
  • although a similar size quake in Tibet in 1950 was of an unknown type
  • 2012 quakes likely were triggered, at least in part, by changes in crustal stresses caused by the magnitude-9.1 Sumatra-Andaman earthquake of Dec. 26, 2004
  • the 8.7 and 8.2 quakes were generated by horizontal movements
  • not by vertical motion
  • explains why they didn't generate major tsunamis
  • 8.7 quake caused small tsunamis, the largest of which measured about 12 inches in height at Meulaboh, Indonesia
  • Indo-Australian plate is breaking into two or perhaps three pieces
  • happening because it is colliding with Asia in the northwest, which slows down the western part of the plate, while the eastern part of the plate continues moving more easily by diving or "subducting" under the island of Sumatra to the northeast
  • subduction zone off Sumatra caused the catastrophic 2004 magnitude-9.1 quake and tsunami
  • ruptured along a roughly 90-mile length
  • seafloor on one side of the fault slipped about 100 feet past the seafloor on the fault's other side
  • second fault, which slipped about 25 feet, began to rupture 40 seconds after
  • extended an estimated 60 miles to 120 miles north-northeast to south-southwest – perpendicular to the first fault and crossing it.
  • third fault was parallel to the first fault and about 90 to the miles southwest
  • started breaking 70 seconds after the quake began
  • along a length of about 90 miles
  • slipped about 70 feet
  • The fourth fault paralleled the first and third faults
  • began to rupture 145 seconds after the quake began
  • fault rupture was roughly 30 miles to 60 miles long.
  • fault slipped about 20 feet past ground on the other side
Mars Base

Google Lat Long: Dive into the Great Barrier Reef with the first underwater imagery in ... - 0 views

google-latlong.blogspot.in/...t-barrier-reef-with-first.html

scibyte65 GoogleMap

shared by Mars Base on 27 Sep 12 - No Cached
  • experience six of the ocean’s most incredible living coral reefs
  • sea turtle swimming among a school of fish
  • follow a manta ray
  • ...3 more annotations...
  • experience the reef at sunset
  • see an ancient boulder coral, which may be several hundred years old
  • drift over the vast coral reef at Maui's Molokini crater
Mars Base

Red Bull Stratos Targets Oct. 8 for Record-Setting Freefall Attempt - 0 views

www.universetoday.com/...ecord-setting-freefall-attempt

scibyte64 RedBullStratos

shared by Mars Base on 26 Sep 12 - No Cached
  • Mars Base on 26 Sep 12
     
    person to break the sound barrier, alone
Mars Base

Dazzling Meteor Fireball Lights Up UK Night Sky | Space.com - 0 views

www.space.com/ball-video-united-kingdom.html

scibyte64 meteorite

shared by Mars Base on 25 Sep 12 - No Cached
  • A spectacular meteor wowed stargazers across the United Kingdom Friday (Sept. 21) when it flared up and shattered into piece
  • spotted by observers across Scotland and northern England as well as Ireland
  • Many observers captured views of the meteor on camera
  • ...9 more annotations...
  • video of the Sept. 21 meteor shows what appears to be a fireball created as a small space rock breaks apart in Earth's atmosphere. Pieces of the meteor can easily be seen separating from the main body in his view
  • many witnesses to wonder if it was sparked by a man-made piece of space junk falling out of orbit
  • experts have conclusively tied the event to a naturally occurring space rock burning up in Earth's atmosphere
  • Veteran satellite tracker Marco Langbroe
  • the fireball was definitely a meteor.
  • sighting reports to determine the fireball's trajectory and studied videos posted by witnesses to determine how long it lasted
  • ack-of-the-envelope reconstruction therefore shows that this must have been a meteoric fireball, quite likely of asteroidal origin, and we definitely can exclude a satellite re-entry
  • meteor in space is called a meteoroid. Only when it flares up in the night sky does it become a meteor. Any remains of the object that reach the ground, meanwhile, are called meteorites
  • Earlier this year, a rare daytime fireball surprised U.S. observers in California and Nevada when it unleashed a sonic boom that some mistook for a small earthquake. The meteor was caused by a minivan-size asteroid and created several meteorites that NASA retrieved in a follow-up search
Mars Base

Astrophysicists spy ultra-distant galaxy amidst cosmic 'dark ages' - 0 views

phys.org/...tra-distant-galaxy-cosmic.html

scibyte64 galaxy

shared by Mars Base on 20 Sep 12 - No Cached
  • combined power of NASA's Spitzer and Hubble space telescopes as well as a cosmic magnification effect, a team
  • has spotted what could be the most distant galaxy ever detected.
  • Light from the young galaxy captured by the orbiting observatories shone forth when the 13.7-billion-year-old universe was just 500 million years old
  • ...19 more annotations...
  • This galaxy is the most distant object we have ever observed with high confidence
  • Future work involving this galaxy—as well as others like it that we hope to find—will allow us to study the universe's earliest objects and how the Dark Ages ended
  • traveled approximately 13.2 billion light-years
  • the universe was just 3.6 percent
  • Objects at these extreme distances are mostly beyond the detection sensitivity of today's largest telescopes
  • astronomers rely on "gravitational lensing
  • predicted by Albert Einstein a century ago
  • gravity of foreground objects warps and magnifies the light from background objects
  • brightening the remote object some 15 times and bringing it into view.
  • small and compact, containing only about 1 percent of the Milky Way's mass
  • leading cosmological theories, the first galaxies should indeed have started out tiny
  • then progressively merged
  • omers plan to study the rise of the first stars and galaxies and the epoch of reionization with the successor to both Spitzer and Hubble—NASA's James Webb Telescope, slated for launch in 2018
  • newly described distant galaxy will likely be a prime target.
  • first galaxies likely played the dominant role in the epoch of reionization
  • event that signaled the demise of the universe's Dark Ages
  • About 400,000 years after the Big Bang, neutral hydrogen gas formed from cooling particles
  • these earliest galaxies is thought to have caused the neutral hydrogen strewn throughout the universe to ionize, or lose an electron
  • during the epoch of reionization, the lights came on in the universe
Mars Base

Dawn Finds Asteroid Vesta is Rich in Hydrogen - 0 views

www.universetoday.com/...roid-vesta-is-rich-in-hydrogen

scibyte64 dawn

shared by Mars Base on 21 Sep 12 - No Cached
  • The giant asteroid Vesta appears to have
  • hydrogen
  • Dawn spacecraft reveals hydrated minerals in a wide area around Vesta’s equator
  • ...17 more annotations...
  • Dawn did not find actual water ice, there are signs of hydrated minerals such as hydroxyl
  • source of the hydrogen within Vesta’s surface appears to be hydrated minerals delivered by carbon-rich space rocks that collided with Vesta at speeds slow enough to preserve their volatile content
  • pitted terrain – looking much like potholes – mark where the volatiles, perhaps both hydroxyl and water, released from hydrated minerals boiled off
  • Hydroxyl has recently been found on the Moon in permanently shadowed craters at the lunar poles
  • scientists thought there might be a chance that water ice may have
  • around the giant asteroid’s poles
  • unlike Earth’s Moon, however, Vesta has no permanently shadowed polar regions
  • strongest signature for hydrogen actually came from regions near the equator. And there, water ice is not stable
  • The holes that were left as the water escaped stretch as much as 0.6 miles (1 kilometer) across and go down as deep as 700 feet (200 meters
  • collisions converted the hydrogen bound to the minerals into water, which evaporated
  • The pits look just like features seen on Mars, but while water was common on Mars, it was totally unexpected on Vesta in these high abundances
  • ults provide evidence that not only were hydrated materials present, but they played an important role in shaping the asteroid’s geology and the surface we see today
  • the first direct measurements describing the elemental composition of Vesta’s surface
  • elemental investigation by the instrument determined the ratios of iron to oxygen and iron to silicon in the surface materials
  • new findings solidly confirm the connection between Vesta and a class of meteorites found on Earth called the Howardite, Eucrite and Diogenite meteorites
  • have the same ratios for these elements
  • n, more volatile-rich fragments of other objects have been identified in these meteor
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