"NASA's twin Voyager probes keep making discoveries in interstellar space," reports Space.com The Voyager mission has detected a new type of "electron burst," which will provide insights into the mechanisms of flaring stars, a new study reports. The bursts occur when cosmic ray electrons — fast-moving particles from far beyond the solar system — are pushed by shock waves generated by solar eruptions. The electrons then accelerate further along cosmic magnetic field lines to incredible speed, study team members said.

"The idea that shock waves accelerate particles is not new," corresponding author Don Gurnett, professor emeritus in physics and astronomy at the University of Iowa, said in a statement. "[But] we detected it in a new realm: the interstellar medium, which is much different than in the solar wind, where similar processes have been observed...."

Eventually, the magnetic field lines propel the cosmic rays to almost the speed of light — nearly 670 times faster than the solar shock waves that first pushed them. (The shock waves move at roughly 1 million mph, or 1.6 million kph, study team members said.)
The article marvels at the fact that the spacecraft are still sending back data regularly from 14 billion miles away, beyond the edge of our solar system, more than 43 years after they left earth. They even detected the original solar shock wave which caused the electron burst "up to a year after the event occurred.

"The wait time happened because the spacecraft are so far from the sun."

"A Mysterious Object Is Hurtling Towards Earth, and Scientists Don't Know What It Is," read Newsweek's headline on Monday, describing an object projected to pass 31,605 miles from earth. (One astronomer told them that was roughly 13% of the average distance between the earth and the moon).

But then a computer model calculated its past trajectories through space, according to the director for NASA's Center for Near Earth Object Studies (CNEOS). "One of the possible paths for 2020 SO brought the object very close to Earth and the Moon in late September 1966," he said in a statement. "It was like a eureka moment when a quick check of launch dates for lunar missions showed a match with the Surveyor 2 mission."

On Wednesday NASA described how a team led by Vishnu Reddy, an associate professor/planetary scientist at the Lunar and Planetary Laboratory at the University of Arizona, tried to prove what they'd seen was a 54-year-old booster rocket: Through a series of follow up observations, Reddy and his team analyzed 2020 SO's composition using NASA's IRTF and compared the spectrum data from 2020 SO with that of 301 stainless steel, the material Centaur rocket boosters were made of in the 1960's. While not immediately a perfect match, Reddy and his team persisted, realizing the discrepancy in spectrum data could be a result of analyzing fresh steel in a lab against steel that would have been exposed to the harsh conditions of space weather for 54 years. This led Reddy and his team to do some additional investigation.

"We knew that if we wanted to compare apples to apples, we'd need to try to get spectral data from another Centaur rocket booster that had been in Earth orbit for many years to then see if it better matched 2020 SO's spectrum," said Reddy. "Because of the extreme speed at which Earth-orbiting Centaur boosters travel across the sky, we knew it would be extremely difficult to lock on with the IRTF long enough to get a solid and reliable data set."

However, on the morning of Dec. 1, Reddy and his team pulled off what they thought would be impossible. They observed another Centaur D rocket booster from 1971 launch of a communication satellite that was in Geostationary Transfer Orbit, long enough to get a good spectrum. With this new data, Reddy and his team were able to compare it against 2020 SO and found the spectra to be consistent with each another, thus definitively concluding 2020 SO to also be a Centaur rocket booster...
So what happens next? 2020 SO made its closest approach to Earth on Dec. 1, 2020 and will remain within Earth's sphere of gravitational dominance — a region in space called the "Hill Sphere" that extends roughly 930,000 miles (1.5 million kilometers) from our planet — until it escapes back into a new orbit around the Sun in March 2021.

As NASA-funded telescopes survey the skies for asteroids that could pose an impact threat to Earth, the ability to distinguish between natural and artificial objects is valuable as nations continue to explore and more artificial objects find themselves in orbit about the Sun.

Astronomers will continue to observe this particular relic from the early Space Age until it's gone.

This week the Microsoft-owned code repository site GitHub released its annual report with statistics about its community, writes programming columnist Mike Melanson: The report offers a deep dive into three specific areas, with a look at developer productivity in the time of COVID, community and collaboration, and open source security. Highlights include increased productivity with 35% more repositories created in 2020 than 2019, a large open source community with more than 56M developers in 2020 with 100M expected by 2025, and security vulnerabilities that often go undetected for more than 4 years before being disclosed and 94% of projects relying on open source components.
"2020 has been a year of extraordinary change," notes GitHub's report. "Yet with 60M+ new repositories created this past year, one thing has remained true — developers came together from all corners of the world to innovate, find connection, and solve problems."

GitHub reports that over 1.9 billion contributions were added in the last year, with users distributed around the globe:

North America:	34%
Asia:	30.7%
Europe:	26.8%
South America:	4.9%
Africa:	2%
Oceania:	1.7%

And while JavaScript is still the most popular language used on the site, Python remains more popular (at #2) than Java (at #3) for the second year in a row.

1. JavaScript
2. Python
3. Java
4. TypeScript
5. C#
6. PHP
7. C++
8. C
9. Shell
10. Ruby

A Reddit user found Google Earth photos showing the Utah monolith may have appeared in its canyon up to five years ago, according to The Daily Beast. But it's gone now: Last week, a team of four people removed the Utah obelisk. One of them, a Utah adventure guide, explained their actions in an Instagram post. "We removed the Utah Monolith because there are clear precedents for how we share and standardize the use of our public lands, natural wildlife, native plants, fresh water sources, and human impacts upon them. The mystery was the infatuation and we want to use this time to unite people behind the real issues here — we are losing our public lands — things like this don't help," Sylvan Christensen wrote.

Although the statue had damaged some of the surrounding rock formations, its real cost came when hordes of tourists drove cars and rode helicopters to the remote canyon to see it, Christensen said. "This land wasn't physically prepared for the population shift (especially during a pandemic)," he wrote. "People arrived by car, by bus, by van, helicopter, planes, trains, motorcycles and E-bikes and there isn't even a parking lot. There aren't bathrooms — and yes, pooping in the desert is a misdemeanor. There was a lot of that."
"The group of four took the big pieces of the monolith and placed them in a wheelbarrow and said 'leave no trace' as they rolled it away," reports CNN, citing a photographer who witnessed the event.

The second mysterious monolith that appeared in Romania has also been "removed by parties unknown," reports the Bay Area Newsgroup. But a third monolith also mysteriously appeared 200 miles south of San Francisco in the small town of Atascadero on Tuesday, according to SFGate. Though their reporter has a theory as to why: Atascadero is a handy place. There's plenty of rugged cowboy types, and plenty of people with the room and machinery to weld and rivet some sheets of metal together. The local band when I was in high school was in fact known for riveting metal parts and tubing onto stages and cars and painting the whole thing silver...

[W]hen Atascadero saw this monolith trend hitting, someone took note of the importance of getting in fast, went out into their garage and built a monolith.
"And then, overnight, it was gone," notes the Bay Area News Group. Forbes describes the young men responsible as "Dressed in camo gear, armed with night-vision goggles and energy drinks," and at least once referencing the QAnon conspiracy theory. "One of the men even states: 'We don't want illegal aliens from Mexico, or outer space.'"

The Bay Area News Group writes: The revelation that the culprits drove five hours from Southern California to tear it down, live-streaming the trek, has angered Central Coast residents. Video shows the four young men chanting "Christ is king" as they tear down the monolith and replace it with a plywood cross. They also made racist and anti-immigrant statements...

In a statement Thursday, Atascadero Mayor Heather Moreno said: "We are upset that these young men felt the need to drive 5 hours to come into our community and vandalize the Monolith.

"The Monolith was something unique and fun in an otherwise stressful time."

GitHub has released its annual Octoverse report, revealing trends in one of the largest developer communities on the planet, including a spike in open source project activity following the start of the COVID-19 pandemic. VentureBeat: JavaScript continues to be the most popular programming language on GitHub, while Python is now the second most popular, followed by Java and the fast-growing TypeScript community. Maintained by GitHub owner Microsoft, TypeScript has climbed from seventh place in 2018 and 2019 to fourth overall this year. PHP and Ruby, languages that ranked among the most popular five years ago, continued to decline in popularity.

Apple has picked "Code Switch" as the best audio show of the year, marking the first time the company has recognized a single podcast in this way. Engadget reports: Code Switch is NPR's weekly discussion on race. While the series has been on the air for the better part of seven years, it became significantly more popular over the summer as people across the US took to protest the death of George Floyd and other instances of racial injustice.

As in past years, the company also shared a selection of the most popular audio shows people listened to through Apple Podcasts. Few surprises here as old favorites like Stuff You Should Know, This American Life and The Daily came out as the most popular shows in the US. When it comes to shows new to 2020, Unlocking Us, Nice White Parents and CounterClock made the top three for the year. Apple's editorial team had their say as well. They picked California Love, Canary by the Washington Post and Dying for Sex as their favorites of 2020. If you're looking for something new to listen to, all three lists are a good place to start.

hackingbear writes: Australian Prime Minister Scott Morrison demanded an apology after a senior Chinese official posted a "fake image" of an Australian soldier holding a knife with blood on it to the throat of an Afghan child, calling it "truly repugnant" and demanding it be taken down. The Australian government has asked Twitter to remove the image, posted on Monday by China's foreign ministry spokesman Zhao Lijian on his official Twitter account, Morrison said. "It is utterly outrageous and cannot be justified on any basis," Morrison said. "The Chinese government should be utterly ashamed of this post. It diminishes them in the world's eyes."

The image is actually an art work, originally posted on Weibo by online artist Wuhe Qilin, based on the recently uncovered war crimes committed by Australian special forces in the Afghan War. On Friday, Australia has told 13 special forces soldiers they face dismissal in relation to an independent report on alleged unlawful killings in Afghanistan, the head of the country's army said on Friday. "It is the Australian government who should feel ashamed for their soldiers killing innocent Afghan civilians," said Hua Chunying, China's foreign ministry spokeswoman, when asked about Morrison's comments. Wuhe Qilin praised Zhao's re-posting [translation: "Deputy Zhao's strong. Go for it!"] of his work.

NBC News reports: Many urban centers have seen residents move out in large numbers since the start of stay-at-home orders in March, but the shift has been especially dramatic for San Francisco, a city that was already experiencing rapid change because of the tech industry. Software engineers, CEOs and venture capitalists have chosen to jump from the Bay Area to places such as Denver, Miami and Austin, Texas, citing housing costs, California's relatively high income tax and the Bay Area's general resistance to rapid growth and change.

The scale of the departures is visible in vacant high-end apartments, moth-balled offices and quieter streets in neighborhoods popular with tech workers. And while no one is exactly celebrating, especially as Covid-19 has devastated the incomes of many people, some residents were ready to take a break from the rich.... Rents may have fallen 20 percent or more from a year ago, but they're still high by national standards, and many artists left the city a long time ago.

Although some companies such as Pinterest have canceled leases, Google is expanding its offices in San Francisco, a sign of the tech industry's attachment to the city despite the local hostility and the predictions of a permanent work-from-home culture...

Tracy Rosenberg, executive director of Media Alliance, a San Francisco nonprofit that is often critical of the power of tech companies, said she wonders whether tech workers will want to return to a place where they've received a mixed welcome. "The level of tech blowback in San Francisco and the Bay Area was going up in intensity," she said. "I think there'll be sort of a reluctance to come back and face that, because that was reaching a level that was hard to live with — when you are the cause of all social problems, in the eyes of a significant part of the population, at least."

"PHP version 8.0 has arrived, bringing with it a major update to the 25-year-old programming language..." writes Tech Republic.

New language features include the nullsafe operator and attributes (commonly known as annotations in other languages) to add metadata to classes — and more: The JIT compiler is designed to bring performance improvements to web applications by turning code into instructions for the CPU at runtime. Meanwhile, union types is a feature that allows data of more than one type to be held by a variable. Named arguments allow developers to assign values to a function by specifying the value name, allowing optional parameters to be ignored. Alongside these, version 8.0 of PHP brings optimizations and enhancements to the language's type system, syntax, error handling and consistency....

Commenting on PHP 8.0, PHP programmer and stitcher.io developer, Brent Roose, noted that the latest version of the language may require developers to review code for any breaking changes.

An anonymous reader shares a report: Satoshi didn't leave much behind when he decided to leave the scene for good back in April, 2011. But, he did leave enough for us to conduct a thorough research into his whereabouts when he was working on Bitcoin. To conduct this research, we gathered data from the following:
Satoshi's Bitcointalk account (539 available posts)
His 34 emails on the cryptography and Bitcoin mailing lists
His 169 commits on SourceForge
The metadata from Bitcoin whitepaper versions from 2008 (PDF) and 2009 (PDF)
The Genesis block
Various Wayback Machine archives

The data-driven part of the research focuses on timestamps from Satoshi's Bitcointalk posts, SourceForge commits, and emails, which represent a total of 742 activity instances from 206 days (not consecutive). The timestamp data starts from October 31, 2008, when he first announced Bitcoin on the cryptography mailing list, and ends on December 13, 2010, when he sent his last email that is known to be UTC timestamped. Using that data we compiled scatter charts in different suspect time zones to see when he was active and when he was not. We then used other data we gathered to further confirm the most likely location he called home. Common suspect locations are the UK (GMT), US Eastern (EST), US Pacific (PST), Japan (JST), and Australia (AEST). The last two were easy to debunk, but the first three prospects needed further examination.

Programming columnist Mike Melanson assesses the news that Guido Van Rossum, the creator of the Python programming language, has come out of retirement to join Microsoft's developer division: The news brought a flurry of congratulations and feature requests, though a few of the suggested features indeed, already exist. Others still were met with informative responses that make the resulting threads worth a perusal, especially if you're looking for a quick "who's who" on Twitter for the world of programming languages. Microsoft's Miguel de Icaza pointed out that this addition adds to the company's now growing list of language designers and contributors:

"The developer division at Microsoft now employs the language designers and contributors to Python, Java, JavaScript, Typescript, F# C#, C++. We just need some PHP, Rust and Swift magic to complete the picture."

[Microsoft senior software engineer Kat Marchán added "We actually have some early ex-moz Rust people too!"]

So, what can we expect from all of this? Is it a corporate takeover of open source, as some further down in the long list of replies always seem to suggest? Or is Microsoft planning the Frankenstein of all languages, with a little bit of this, a little bit of that? In all likelihood, you Python developers using Microsoft products probably have some good features to look forward to in the near future, and that's that, but there's always lingering fears...especially when it comes to Microsoft. As van Rossum suggests, stay tuned.
After Slashdot's earlier story, long-time reader alexgieg posted his own theory: "Several months ago the Excel folk within Microsoft asked users whether they'd like to have Python as an alternative scripting language in Office. Support for that was overwhelming, but nothing more was said on the matter since then. I guess this is Microsoft's answer."

An anonymous reader shares an excerpt from a report via VICE: Like other gig work giants, DoorDash has admitted in its IPO documents that its own business model -- and the way it treats and pays workers -- are major "risks" to its business. In its S-1 filing with the Securities and Exchanges Commission, there's little to no evidence DoorDash can achieve let alone sustain profitability (in fact, that it may never be profitable is another "risk"), and lots of evidence that its business model is largely based on taking advantage of both restaurants and drivers.

Included in "risks" are the two following statements, which are wonders to behold: "Our success, or perceived success, and increased visibility may also drive some businesses that perceive our business model negatively to raise their concerns to local policymakers and regulators. These businesses and their trade association groups or other organizations may take actions and employ significant resources to shape the legal and regulatory regimes in jurisdictions where we may have, or seek to have, a market presence in an effort to change such legal and regulatory regimes in ways intended to adversely affect or impede our business and the ability of merchants, consumers, and Dashers to use our platform." What this means is that restaurants might want DoorDash to take less of a cut from their commission, which is understandable. Even with cuts to DoorDash's commission rates during the pandemic, many restaurants are still struggling to scrape by.

And then there's this, which explicitly says the company's own pay model for drivers is a risk to its further existence: "Our ability to provide a cost-effective local logistics platform is also dependent on Dasher pay, which is a significant cost and subject to a number of risks..." That's a mouthful, but says that DoorDash's pay model for delivery drivers is algorithmic, which leads to an "inconsistency in earnings" which is likely to piss off both its workforce and its customers to the point where it may be challenged both in court and by regulators, and reported on in the media. This problem is even worse when you consider the labor patterns of gig companies: they require a large reserve of idle labor to keep wait times low and to fight extremely high turnover rates, but they also rely on a core of full-time gig workers to do the vast majority of work. As a result, the workers hurt the most by this "inconsistency in earnings" are the most precarious and vulnerable workers who rely on DoorDash to make ends meet.

Long-time Slashdot reader fahrbot-bot shared this report from the New York Times: A decade ago, a band of astronomers set out to investigate one of the oldest questions taunting philosophers, scientists, priests, astronomers, mystics and the rest of the human race: How many more Earths are out there, if any? How many far-flung planets exist that could harbor life as we know it?

Their tool was the Kepler spacecraft, which was launched in March 2009 on a three-and-a-half year mission to monitor 150,000 stars in a patch of sky in the Milky Way. It looked for tiny dips in starlight caused by an exoplanet passing in front of its home star. "It's not E.T., but it's E.T.'s home," said William Borucki when the mission was launched in March 2009. It was Dr. Borucki, an astronomer now retired from NASA's Ames Research Center, who dreamed up the project and spent two decades convincing NASA to do it. Before the spacecraft finally gave out in 2018, it had discovered more than 4,000 candidate worlds among those stars. So far, none have shown any sign of life or habitation. (Granted, they are very far away and hard to study.) Extrapolated, that figure suggests that there are billions of exoplanets in the Milky Way galaxy. But how many of those are potentially habitable?

After crunching Kepler's data for two years, a team of 44 astronomers led by Steve Bryson of NASA Ames has landed on what they say is the definitive answer, at least for now. Their paper has been accepted for publication in the Astronomical Journal... The team calculated that at least one-third, and perhaps as many as 90 percent, of stars similar in mass and brightness to our sun have rocks like Earth in their habitable zones, with the range reflecting the researchers' confidence in their various methods and assumptions. That is no small bonanza, however you look at it.

According to NASA estimates there are at least 100 billion stars in the Milky Way, of which about 4 billion are sunlike. If only 7 percent of those stars have habitable planets — a seriously conservative estimate — there could be as many as 300 million potentially habitable Earths out there in the whole Milky Way alone.

On average, the astronomers calculated, the nearest such planet should be about 20 light-years away, and there should be four of them within 30 light-years or so of the sun...
"The new result means that the galaxy is at least twice as fertile as estimated in one of the first analyses of Kepler data, in 2013."

"Security firm Kaspersky said Friday that it discovered a Linux version of the RansomEXX ransomware," reports ZDNet, "marking the first time a major Windows ransomware strain has been ported to Linux to aid in targeted intrusions." RansomEXX is a relatively new ransomware strain that was first spotted earlier this year in June. The ransomware has been used in attacks against the Texas Department of Transportation, Konica Minolta, U.S. government contractor Tyler Technologies, Montreal's public transportation system, and, most recently, against Brazil's court system (STJ)...

The RansomEXX gang creating a Linux version of their Windows ransomware is in tune with how many companies operate today, with many firms running internal systems on Linux, and not always on Windows Server. A Linux version makes perfect sense from an attacker's perspective; always looking to expand and touch as much core infrastructure as possible in their quest to cripple companies and demand higher ransoms. What we see from RansomEXX may soon turn out to be an industry-defining trend, with other big ransomware groups rolling out their Linux versions in the future as well.

And, this trend appears to have already begun. According to cyber-security firm Emsisoft, besides RansomEXX, the Mespinoza (Pysa) ransomware gang has also recently developed a Linux variant from their initial Windows version.

"Boeing's much-maligned 737 Max jet could be cleared to fly again in just a few weeks," reports SFGate, adding that one U.S. airline plans to carry passengers "as early as December." Although the Federal Aviation Administration has not disclosed a public timeline for the Max's return to service, approval to lift the grounding could come as early as mid-November, according to Reuters. Boeing executives said they expect to gain FAA recertification before the end of the year. The company will also need to get approval from the European Union Aviation Safety Agency and Transport Canada, which are conducting their own respective reviews...

American Airlines said it plans to operate one daily Boeing 737 Max roundtrip from Dec. 29 through Jan. 4 between its Miami hub and New York's LaGuardia Airport. If it takes off, American will be the first US carrier to bring back the Max...

Other U.S. airlines operating the Max are taking a wait-and-see approach before assigning the fleet type to flights.

According to Phoronix, a Dell privacy driver is is being prepared for the Linux kernel. From the report: Beginning in Dell's 2021 laptop models they are providing hardware-based "privacy buttons" to disable microphone and camera support. These new Dell privacy buttons are basically hardware kill switches for the microphone and web camera video stream. The Dell privacy driver sent out on Tuesday for the Linux kernel is about manipulating the relevant LEDs and tracking the status of the hardware-based controls where as the actual toggling of the audio/video support is handled by the hardware.

The Dell privacy driver in its current form is talked about for the camera and microphone support but the patch does also note a "PRIVACY_SCREEN_STATUS" bit as well. Presumably they will be extending this privacy driver as well for privacy screen handling around reducing the horizontal/vertical viewing angles of the display. The dell-privacy Linux driver in its initial form can be found via the kernel mailing list. It's great seeing Dell working on this driver punctually for Linux ahead of their next-gen laptops.

AmiMoJo writes: As we roll into 2021 the Free Software Foundation is looking to update its high priority free software projects list. These are the software projects that should be incorporating "the most important threats, and most critical opportunities, that free software faces in the modern computing landscape." For now the FSF is looking for help deciding what to include. The FSF high priority projects list is what once included PowerVR reverse engineering as being very important albeit never happened prior to PowerVR graphics becoming less common. In fact, many FSF high priority projects never panned out as they weren't contributing much in the way of resources to the causes but just calling attention to them. PDF support was among their high priority projects as well as another example as well as the likes of an open-source Skype replacement and reverse-engineering other popular technologies.

They overhauled the list in 2017 after forming a committee to maintain the list while now as 2021 is just around the corner they are looking to revise their high priority projects focus once more. They have issued a call for input to share with the High Priority Free Software Projects committee what you feel should belong on the list. Feedback is being collected through early January. Currently on the list are different "areas" they feel are high priority for free software as opposed to previously focusing on particular projects.

In preparation for next year's Xe HPG graphics cards, Intel's open-source developers have begun publishing their patches enabling their "ANC" Vulkan Linux driver to support Vulkan ray-tracing. Phoronix reports: Jason Ekstrand as the lead developer originally on the Intel ANV driver has posted today the initial ray-tracing code for ANV in order to support VK_KHR_ray_tracing for their forthcoming hardware. Today is the first time Intel has approved of this open-source code being published and more is on the way. The code today isn't enough for Vulkan ray-tracing but more is on the way and based against the latest internal Khronos ray-tracing specification. At the moment they are not focusing on the former NVIDIA-specific ray-tracing extension but may handle it in the future if game vendors continue targeting it rather than the forthcoming finalized KHR version.

Among other big ticket items still to come in the near-term includes extending the ANV driver to support compiling and dispatching OpenCL kernels, new SPIR-V capabilities, and generic pointer support. Also needed is the actual support for compiling ray-tracing pipelines, managing acceleration structures, dispatching rays, and the platform support. The actual exposing of the support won't come until after The Khronos Group has firmed up their VK_KHR_ray_tracing extension. Some of this Intel-specific Vulkan ray-tracing code may prove useful to Mesa's Radeon Vulkan "RADV" driver as well. Intel engineers have been testing their latest ray-tracing support with ANV internally on Xe HPG.

An anonymous reader quotes a report from Ars Technica: In recent years, the cost of solar and wind energy has declined precipitously, which has accelerated the growth of these renewable energy technologies. Increasingly, utilities are now planning for a future grid dominated by solar and wind. That will require changes in grid management and transmission upgrades as well as the addition of storage to smooth out the supply from variable generators. Grid storage is still pretty early days, but we're already seeing huge cost reductions as the industry matures. The US Energy Information Administration (EIA) highlighted this recently, showing that grid-scale battery-project costs in the United States dropped 70 percent in just a few years.

Between 2015 and 2018, average project costs decreased from $2,152 per kilowatt-hour of storage to $625. Costs will need to drop much more for grid batteries to scale, but that's a huge improvement in a short period of time. By the end of 2018, the US had 869 megawatts of battery power capacity and 1,236 megawatt-hours of energy capacity. (Power is the rate at which the batteries can supply electricity, while energy is the total amount it can supply when going from full charge to empty.) EIA also has installation data for 2019, which saw the addition of another 150 megawatts/450 megawatt-hours. And in just the first seven months of 2020, yet another 300 megawatts of power capacity were installed. EIA doesn't see this slowing down. It expects installed battery storage to increase by 6,900 megawatts "in the next few years" -- a figure ambiguous enough to allow for a rapid spike in planned projects.

An anonymous reader quotes a report from IEEE Spectrum: In April, Guoping Feng and colleagues at MIT, along with [Karl Deisseroth, a neuroscientist and bioengineer at Stanford University] demonstrated a minimally invasive optogenetic system that required drilling a small hole in the skull, then being able to control opsin-expressing neurons six millimeters deep into the brain using blue light. This approach used of a type of opsin that slowly activates neurons in a step-wise manner. In the most recent study [published in the journal Nature Biotechnology], Deisseroth and colleagues sought to instead enable both deep and fast optogenetics without surgery. The Stanford team expressed in the brain cells of mice a powerful new opsin called ChRmine (pronounced like the deep-red color "carmine"), discovered by Deisseroth's group last year in a marine organism. Then, they shined a red light outside the skull and were able to activate neural circuits in the midbrain and brainstem at depths of up to 7 millimeters. With the technique, the scientists turned on and off brain circuits with millisecond precision. "It really worked well, far better than we even expected might be possible," says Deisseroth.

The team then tested the effectiveness of the system. In one instance, they used light to quickly and precisely stop seizures in epileptic mice, and in another to turn on serotonin-producing neurons to promote social behavior in mice. Most optogenetic techniques involve injecting viruses with an opsin gene of choice directly into the brain with a needle. To avoid this, the Stanford team used a type of PHP virus developed at CalTech that can be injected in the blood. The virus then crosses the blood-brain barrier to deliver its payload, an opsin gene, to brain cells. In this case, even the delivery of the gene is noninvasive -- no needle penetrates the brain. Deisseroth's team is now testing the non-invasive technique in fish and collaborating with others to apply it to non-human primates. They're also working with the Seattle-based Allen Institute to develop mouse lines bred with ChRmine in their cells.