SciByte

The decision to resume science activities resulted from the success of work to diagnose the likely root cause of a Nov. 17 change in voltage

made a list of potential causes, and then determined which we could cross off the list, one by one

Science operations were suspended for six days while this analysis took priority

The likely cause is an internal short in Curiosity's power source, the Multi-Mission Radioisotope Thermoelectric Generator

this short does not affect operation of the power source or the rover

Similar generators on other spacecraft, including NASA's Cassini at Saturn, have experienced shorts with no loss of capability

Testing of another Multi-Mission Radioisotope Thermoelectric Generator over many years found no loss of capability in the presence of these types of internal shorts

early Nov. 23

that the rover had returned to its pre-Nov. 17 voltage level. This reversal is consistent with their diagnosis of an internal short in the generator on Nov. 17, and the voltage could change again

analysis work to determine the cause of the voltage change gained an advantage from an automated response by the rover's onboard software when it detected the voltage change

The rover stepped up the rate at which it recorded electrical variables, to eight times per second from the usual once per minute, and transmitted that engineering data in its next communication with Earth

In subsequent days, the rover performed diagnostic activities commanded by the team, such as powering on some backup hardware to rule out the possibility of short circuits in certain sensors

A "soft" short is a leak through something that's partially conductive of electricity, rather than a hard short such as one electrical wire contacting another

The level had been about 11 volts since landing day, and is now about 4 volts

The rover's electrical system is designed with the flexibility to work properly throughout that range and more -- a design feature called "floating bus."

Curiosity had already experienced one soft short on landing day in August 2012

A soft short can cause such a voltage change

That one was related to explosive-release devices used for deployments shortly before and after the landing

It lowered the bus-to-chassis voltage from about 16 volts to about 11 volts but has not affected subsequent rover operations

Soft shorts reduce the level of robustness for tolerating other shorts in the future, and they can indicate a possible problem in whichever component is the site of the short

Operations planned for Curiosity for the next few days are designed to check some of the possible root causes for the voltage change

Analysis so far has determined that the change appeared intermittently three times during the hours before it became persistent

The electrical issue did not cause the rover to enter a safe-mode status, in which most activities automatically cease pending further instructions, and there is no indication the issue is related to a computer reboot that triggered a "safe-mode" earlier this month

Billions of neutrinos pass through a square centimeter of Earth every second, and only a tiny fraction of them interact with matter

IceCube is located inside a cubic kilometer of ice beneath the South Pole. The observatory consists of 5,160 digital optical modules suspended from 86 strings

This cooling effect allowed the

facility to grow three crops per year, even in the scorching summer

At the other end of the greenhouse is a network of pipes with cold seawater running through them

Some of the moisture in the air condenses on the pipes and is collected, providing a source of fresh water

One of the surprising side effects of such a seawater greenhouse, seen during early experiments, is that cool moist air leaking out of it encourages other plants to grow spontaneously outside

Qatar plant took advantage of that effect to grow crops around the greenhouse, including barley and salad rocket (arugula), as well as useful desert plants

The pilot plant accentuated this exterior cooling with more “evaporative hedges” that reduced air temperatures by up to 10°C.

The third key element of the SFP facility is a concentrated solar power plant

This uses mirrors in the shape of a parabolic trough to heat a fluid flowing through a pipe at its focus. The heated fluid then boils water, and the steam drives a turbine to generate power

the plant has electricity to run its control systems and pumps and can use any excess to desalinate water for irrigating the plants

The fact that this small greenhouse produced such good yields,

suggests that a commercial plant—with possibly four crops a year—could do even better

Only the largest eruptions could melt all the ice above them and poke through to the surface, but even smaller eruptions could potentially cause global sea level to rise, although no one knows how big the rise might be

The crust is thinned by the West Antarctic Rift System, a series of giant rift valleys beneath the ice sheet

erupted lava from underground magma chambers has burst through the ice repeatedly over geological history as the plates moved over the top

No one knew whether magma was still stirring

until seismic monitoring stations were installed on the ice between 2007 and 2010.

Researchers built the stations to study the shifting crustal blocks of the West Antarctic Rift System

But seismologist

found another use

They noticed a series of small earthquakes, mainly occurring during two “seismic swarms” in January and February 2010 and March 2011

These earthquakes were unusual: The ground was shaking much more slowly during the quakes than one would expect from the plates grinding against each other

looked at two different types of waves that come in—the P wave, which is the primary wave, and the S wave, which is the secondary wave

calculations revealed that the waves had come from 25 to 40 kilometers below Earth's surface and were centered around a point

approximately the point the volcanic activity should have reached if it had continued the linear trend of volcanoes to the south

The exact cause of these deep quakes is not understood, but they are thought to result from the movement of magma deep below active or soon-to-be active volcanoes

They found that the area showed a slightly higher magnetic field than the surrounding area and that there was a bump in the crust—common signals of magmatic activity

Radar mapping also indicated a layer of volcanic ash embedded in the ice

probably

from an eruption of Mount Waesche about 8000 years ago—very recent geological history

There is no evidence of an actual eruption since then, but, because magma is still moving deep under the Earth, an eruption could occur at any time

The current center of volcanic activity is covered by at least 1 kilometer of ice, and it would take an exceptionally large eruption to melt all this

But an eruption could make its presence felt in subtler ways. As fresh snow adds to their own mass, ice sheets flow downward into the sea

melting the base of the ice sheet, an eruption could speed up this flow, potentially raising the level of the ocean. No one knows how significant such a rise might be

Any effect on the ice sheet above, and thus any effect on the oceans, would probably be quite small

a proper study is needed to find out how significant volcanic activity could be to future sea levels

These events constitute the first solid evidence for astrophysical neutrinos from cosmic sources

The sources of neutrinos, and the question of what could accelerate these particles, has been a mystery for more than 100 years

IceCube is made up of 5,160 digital optical modules suspended along 86 strings embedded in ice beneath the South Pole

It detects neutrinos through the tiny flashes of blue light, called Cherenkov light, produced when neutrinos interact in the ice.

Computers then collect near-real-time data from the optical sensors and send information about interesting events north via satellite

astrophysical neutrinos move in straight lines unimpeded by outside forces, they can act as pointers to the place in the galaxy where they originated

This, in turn, can tell astronomers quite a bit out our universe

The 28 events recorded so far are too few to point to any particular location

a search for "apple" might return images of fruit as well as laptop computers

team had no idea that a search for F-18 would identify not only images of a fighter jet, but also of F18-class catamarans

As its search proceeds, NEIL develops subcategories of objects

tricycles can be for kids, for adults and can be motorized, or cars come in a variety of brands and models

it begins to notice associations – that zebras tend to be found in savannahs, for instance, and that stock trading floors are typically crowded

The goal is to recreate what we call common sense—the ability to learn things without being specifically taught

NEIL uses advances in computer vision to analyze and identify the shapes and colors in pictures, but it is also slowly discovering connections between objects on its own

the computers have figured out that zebras tend to be found in savannahs and that tigers look somewhat like zebras

In just over four months, the network of 200 processors has identified 1,500 objects and 1,200 scenes and has connected the dots to make 2,500 associations

Some of NEIL's computer-generated associations are wrong

"rhino can be a kind of antelope,"

"actor can be found in jail cell"

"news anchor can look similar to Barack Obama."

having a computer make its own associations is an entirely different type of challenge than programming a supercomputer to do one thing very well, or fast

humans constantly make decisions using "this huge body of unspoken assumptions," while computers don

humans can also quickly respond to some questions that would take a computer longer to figure out

"Could a giraffe fit in your car?" she asked. "We'd have an answer, even though we haven't thought about it" in the sense of calculating the giraffe's body mass

In the future, NEIL will analyze vast numbers of YouTube videos to look for connections between objects

It will take the spacecraft 10 months to reach the Red Planet, with arrival scheduled for Sept. 22, 2014

MAVEN’s purpose is to accomplish world class science after arriving at Mars and completing a check-out period before it can finally begin collecting science data

MAVEN will answer key questions about the evolution of Mars, its geology and the potential for the evolution of life

Mars was once wet billions of years ago,

Now it’s a cold arid world, not

hospitable to life

want to determine what were the drivers of that change

What is the history of Martian habitability, climate change and the potential for life

MAVEN will study Mars upper atmosphere to explore how the Red Planet may have lost its atmosphere over billions of years

It will measure current rates of atmospheric loss to determine how and when Mars lost its atmosphere and water

The MAVEN probe carries nine sensors in three instrument suites

The Particles and Fields Package,

contains six instruments to characterize the solar wind and the ionosphere of Mars.

The Remote Sensing Package,

will determine global characteristics of the upper atmosphere and ionosphere.

The Neutral Gas and Ion Mass Spectrometer,

will measure the composition of Mars’ upper atmosphere.

Over the course of its one-Earth-year primary mission, MAVEN will observe all of Mars’ latitudes at altitudes ranging from 93 miles to more than 3,800 miles.

MAVEN will execute five deep dip maneuvers during the first year, descending to an altitude of 78 miles. This marks the lower boundary of the planet’s upper atmosphere.

when an unexpected software reboot (also known as a warm reset) occurred during a communications

After analyzing the data returned by the spacecraft on

Nov. 7

Curiosity operations team was able to determine the root cause. An error in existing onboard software resulted in an error in a catalog file

This caused an unexpected reset when the catalog was processed by a new version of flight software which had been installed on Thursday

The team was able to replicate the problem on ground testbeds the following day

Commands recovering the spacecraft were uplinked to the spacecraft early Sunday

the establishment of the Romanov dynasty in Russia, the building of the Taj Majal in India, two world wars

now researchers are reporting it's more than an entire century older than that: a healthy 507 years

originally, researchers counted the rings on its shell, which usually provides an accurate count, since the clams produce another ring each summer

the rings were so compressed there was apparently a miscount

. A new count of rings on the exterior, confirmed by carbon dating, gave the new age

Ming's slow metabolism is what allows it to survive for so long

Ming died

back in 2006

it's not unlikely that an even older one has been found and not properly researched