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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

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

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

A soft short can cause such a voltage change

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

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

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

required three functioning wheels to maintain the precision pointing necessary to detect the signal of small Earth-sized exoplanets

With the failure of a second reaction wheel, the spacecraft can no longer precisely point at the mission's original field of view. The culprit is none other than our own sun

pushes the spacecraft around

the pressure exerted when the photons of sunlight strike the spacecraft

Without a third wheel to help counteract the solar pressure, the spacecraft's ultra-precise pointing capability cannot be controlled in all directions.

Kepler mission and Ball Aerospace engineers have developed an innovative way of recovering pointing stability by maneuvering the spacecraft so that the solar pressure is evenly distributed across the surfaces of the spacecraft

To achieve this level of stability, the orientation of the spacecraft must be nearly parallel to its orbital path around the sun

This technique of using the sun as the 'third wheel' to control pointing is currently being tested on the spacecraft and early results are already coming i

During a pointing performance test in late October, a full frame image of the space telescope's full field of view was captured showing part of the constellation Sagittarius

Photons of light from a distant star field were collected over a 30-minute period and produced an image quality within five percent of the primary mission image quality

Additional testing is underway to demonstrate the ability to maintain this level of pointing control for days and weeks.

The K2 mission concept has been presented to NASA Headquarters

A decision to proceed to the 2014 Senior Review – a biannual assessment of operating missions – and propose for budget to fly K2 is expected by the end of 2013

For four years, the space telescope simultaneously and continuously monitored the brightness of more than 150,000 stars, recording a measurement every 30 minutes.