SciByte

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

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

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.

13-km-wide Phobos has been spotted several times before by Mars rovers

most recently during a solar transit on September 13 (sol 37)

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

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

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

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

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

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