"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.

China successfully powered up its "artificial sun" nuclear fusion reactor for the first time, state media reported Friday, marking a great advance in the country's nuclear power research capabilities. Phys.Org reports: The HL-2M Tokamak reactor is China's largest and most advanced nuclear fusion experimental research device, and scientists hope that the device can potentially unlock a powerful clean energy source. It uses a powerful magnetic field to fuse hot plasma and can reach temperatures of over 150 million degrees Celsius, according to the People's Daily -- approximately ten times hotter than the core of the sun. Located in southwestern Sichuan province and completed late last year, the reactor is often called an "artificial sun" on account of the enormous heat and power it produces. They plan to use the device in collaboration with scientists working on the International Thermonuclear Experimental Reactor -- the world's largest nuclear fusion research project based in France, which is expected to be completed in 2025.

The programming language JavaScript emerged 25 years ago and has grown to become one of the most important pieces of the web and browser applications we use today. From a report: JavaScript is the go-to language for front-end development and has spawned Microsoft's Typescript, a superset of JavaScript with a stronger optional type system for developers that compiles to JavaScript when run in the browser. Both JavaScript and TypeScript conform to ECMAScript, the standard for JavaScript and node.js, the runtime for running applications outside of the browser thanks to Google's powerful V8 JavaScript engine. JavaScript's impact on the web cannot be understated. Tech giants have thrown their weight behind the language. Besides Google's V8, there are open source projects like React from Facebook and Angular from Google, which help spread web applications across smartphones and desktop. After Netscape and Sun Microsystems -- where Java was hatched in May 1995 by James Gosling -- announced JavaScript in December 1995, Microsoft promoted Visual Basic (VB) as a standard for creating web applications using VB Script for its Internet Explorer browser. Oracle would go on to buy Sun Microsystems in 2008 largely to get its hands on Java and its huge development ecosystem. The press release about its launch from 25 years ago.

An anonymous reader shares a report: Dec. 2 was the 25th anniversary of the Solar and Heliospheric Observatory (SOHO), a joint project from NASA and the European Space Agency. To celebrate, the agencies released a dramatic, nearly 50-minute-long video showing the sun blasting out solar material from 1998 through 2020. The SOHO spacecraft constantly stares at the sun, recording its every whim. It's spectacular and mesmerizing. "What becomes clear as the sun turns and years pass and background stars whirl by, is how constant the stream of material is that is blasted in all directions -- the solar wind," ESA said in a statement on Wednesday. "This constant wind is interrupted only by huge explosions that fling bows of material at vast speeds, filling the solar system with ionized material and solar radiation."

NBC News calls it "the ghostly signal that reveals the engine of the universe." Long-time Slashdot reader fahrbot-bot shares their report: In research published Wednesday in the journal Nature, scientists reported that they've made the first detection of almost-ethereal particles called neutrinos that can be traced to carbon-nitrogen-oxygen fusion, known as the CNO cycle, inside the sun. It's a landmark finding that confirms theoretical predictions from the 1930s, and it's being hailed as one of the greatest discoveries in physics of the new millenium. "It's really a breakthrough for solar and stellar physics," said Gioacchino Ranucci of the Italian National Institute for Nuclear Physics (INFN), one of the researchers on the project since it began in 1990.

The scientists used the ultrasensitive Borexino detector at the INFN's Gran Sasso particle physics laboratory in central Italy — the largest underground research center in the world, deep beneath the Apennine Mountains, about 65 miles northeast of Rome. The detection caps off decades of study of the sun's neutrinos by the Borexino project, and reveals for the first time the main nuclear reaction that most stars use to fuse hydrogen into helium... Scientists calculate that the CNO cycle is the primary type of fusion in the universe. But it's hard to spot inside our relatively cool sun, where it accounts for only 1 percent of its energy...

Ranucci said the Borexino detector has spent decades measuring neutrinos from the sun's main proton-proton chain reaction, but detecting its CNO neutrinos has been very difficult — only about seven neutrinos with the tell-tale energy of the CNO cycle are spotted in a day. The discovery required making the detector ever more sensitive over the last five years, Ranucci said, by shielding it from outside sources of radioactivity so that the inner chamber of the detector is the most radiation-free place on Earth.

Amateur astronomer and YouTuber Alberto Caballero, one of the founders of The Exoplanets Channel, has found a small amount of evidence for a source of the notorious Wow! signal. Phys.Org reports: Back in 1977, astronomers working with the Big Ear Radio Telescope -- at the time, situated in Delaware, Ohio -- recorded a unique signal from somewhere in space. It was so strong and unusual that one of the workers on the team, Jerry Ehman, famously scrawled the word Wow! on the printout. Despite years of work and many man hours, no one has ever been able to trace the source of the signal or explain the strong, unique signal, which lasted for all of 72 seconds. Since that time, many people have suggested the only explanation for such a strong and unique signal is extraterrestrial intelligent life.

In this new effort, Caballero reasoned that if the source was some other life form, it would likely be living on an exoplanet -- and if that were the case, it would stand to reason that such a life form might be living on a planet similar to Earth -- one circling its own sun-like star. Pursuing this logic, Caballero began searching the publicly available Gaia database for just such a star. The Gaia database has been assembled by a team working at the Gaia observatory run by the European Space Agency. Launched back in 2013, the project has worked steadily on assembling the best map of the night sky ever created. To date, the team has mapped approximately 1.3 billion stars. In studying his search results, Caballero found what appears to fit the bill -- a star (2MASS 19281982-2640123) that is very nearly a mirror image of the sun -- and is located in the part of the sky where the Wow! signal originated. He notes that there are other possible candidates in the area but suggests his candidate might provide the best launching point for a new research effort by astronomers who have the tools to look for exoplanets. Caballero shared his findings via arXiv.

Ars Technica glimpsed a possible future at the Johns Hopkins University Applied Physics Laboratory: a solar simulator "that can shine with the intensity of 20 Suns..."

"They think it could be the key to interstellar exploration." "It's really easy for someone to dismiss the idea and say, 'On the back of an envelope, it looks great, but if you actually build it, you're never going to get those theoretical numbers,'" says Benkoski, a materials scientist at the Applied Physics Laboratory and the leader of the team working on a solar thermal propulsion system. "What this is showing is that solar thermal propulsion is not just a fantasy. It could actually work."

In 2019, NASA tapped the Applied Physics Laboratory to study concepts for a dedicated interstellar mission. At the end of next year, the team will submit its research to the National Academies of Sciences, Engineering, and Medicine's Heliophysics decadal survey, which determines Sun-related science priorities for the next 10 years... In mid-November, [APL's] Interstellar Probe researchers met online for a weeklong conference to share updates as the study enters its final year. At the conference, teams from APL and NASA shared the results of their work on solar thermal propulsion, which they believe is the fastest way to get a probe into interstellar space.

The idea is to power a rocket engine with heat from the Sun, rather than combustion. According to Benkoski's calculations, this engine would be around three times more efficient than the best conventional chemical engines available today. "From a physics standpoint, it's hard for me to imagine anything that's going to beat solar thermal propulsion in terms of efficiency," says Benkoski. "But can you keep it from exploding...?" If the interstellar probe makes a close pass by the Sun and pushes hydrogen into its shield's vasculature, the hydrogen will expand and explode from a nozzle at the end of the pipe. The heat shield will generate thrust. It's simple in theory but incredibly hard in practice.

A solar thermal rocket is only effective if it can pull off an Oberth maneuver, an orbital-mechanics hack that turns the Sun into a giant slingshot. The Sun's gravity acts like a force multiplier that dramatically increases the craft's speed if a spacecraft fires its engines as it loops around the star... The big takeaway from his research, says Dean Cheikh, a materials technologist at NASAâ(TM)s Jet Propulsion Laboratory, is there's a lot of testing that needs to be done on heat shield materials before a solar thermal rocket is sent around the Sun. But it's not a deal-breaker. "Additive manufacturing is a key component of this, and we couldn't do that 20 years ago. Now I can 3D-print metal in the lab."

Thelasko shares a report from Forbes: In a major milestone, the New Zealand-based launch company Rocket Lab has successfully recovered an orbital-class rocket after parachuting it back to Earth from near-space -- only the second company in history ever to do so. Yesterday, Thursday, November 20 at 9.20 P.M. Eastern Time, the company's two-stage Electron rocket lifted off from the company's launch site on the Mahia Peninsula on New Zealand's North Island.

Named 'Return to Sender', the mission lofted 30 satellites into a sun-synchronous orbit 500 kilometers above the surface of Earth -- the most satellites ever flown on an Electron rocket. Of the satellites launched, 24 were small communications satellites called "SpaceBees" from the California-based company Swarm Technologies. The others included a space junk removal test, a maritime observation satellite, and an earthquake investigation satellite -- while a small gnome also made its way to space for charity. The launch was especially notable, however, for Rocket Lab's recovery efforts. Shortly after the launch, the first stage of the rocket descended back to Earth under parachute, falling into the ocean where it was then recovered by a waiting ship several hours later. Rocket Lab's plan is to catch its smaller rockets with a helicopter as they fall from space under a parachute. At some point, possibly next year, the first helicopter recovery will be attempted.

"First, the company says it wants to perform a few more splashdown tests in the ocean like this one, to check everything is nominal," reports Forbes. "If all goes well, however, SpaceX quite soon might not be the only private company that's able to launch, recover, and re-launch its own rockets."

Amanda Jane Hughes, Lecturer, Department of Mechanical, Materials and Aerospace Engineering at University of Liverpool Stefania, and Soldini Lecturer in Aerospace Engineering at University of Liverpool, write: A space-based solar power station could orbit to face the Sun 24 hours a day. The Earth's atmosphere also absorbs and reflects some of the Sun's light, so solar cells above the atmosphere will receive more sunlight and produce more energy. But one of the key challenges to overcome is how to assemble, launch and deploy such large structures. A single solar power station may have to be as much as 10 kilometres squared in area -- equivalent to 1,400 football pitches. Using lightweight materials will also be critical, as the biggest expense will be the cost of launching the station into space on a rocket. One proposed solution is to develop a swarm of thousands of smaller satellites that will come together and configure to form a single, large solar generator. In 2017, researchers at the California Institute of Technology outlined designs for a modular power station, consisting of thousands of ultralight solar cell tiles. They also demonstrated a prototype tile weighing just 280 grams per square metre, similar to the weight of card.

Recently, developments in manufacturing, such as 3D printing, are also being looked at for this application. At the University of Liverpool, we are exploring new manufacturing techniques for printing ultralight solar cells on to solar sails. A solar sail is a foldable, lightweight and highly reflective membrane capable of harnessing the effect of the Sun's radiation pressure to propel a spacecraft forward without fuel. We are exploring how to embed solar cells on solar sail structures to create large, fuel-free solar power stations. These methods would enable us to construct the power stations in space. Indeed, it could one day be possible to manufacture and deploy units in space from the International Space Station or the future lunar gateway station that will orbit the Moon. Such devices could in fact help provide power on the Moon. The possibilities don't end there. While we are currently reliant on materials from Earth to build power stations, scientists are also considering using resources from space for manufacturing, such as materials found on the Moon.

Researchers with NASA's New Horizons say they've finally been able to determine if space is truly black. The group has posted their work online, and it will soon appear ini the Astrophysical Journal. NPR reports: New Horizons was originally designed to explore Pluto, but after whizzing past the dwarf planet in 2015, the intrepid spacecraft just kept going. It's now more than four billion miles from home -- nearly 50 times farther away from the Sun than the Earth is. That's important because it means the spacecraft is far from major sources of light contamination that make it impossible to detect any tiny light signal from the universe itself. Around Earth and the inner solar system, for example, space is filled with dust particles that get lit up by the Sun, creating a diffuse glow over the entire sky. But that dust isn't a problem out where New Horizons is. Plus, out there, the sunlight is much weaker.

To try to detect the faint glow of the universe, researchers went through images taken by the spacecraft's simple telescope and camera and looked for ones that were incredibly boring. Then they processed these images to remove all known sources of visible light. Once they'd subtracted out the light from stars, plus scattered light from the Milky Way and any stray light that might be a result of camera quirks, they were left with light coming in from beyond our own galaxy. They then went a step further still, subtracting out light that they could attribute to all the galaxies thought to be out there. And it turns out, once that was done, there was still plenty of unexplained light.

In fact, the amount of light coming from mysterious sources was about equal to all the light coming in from the known galaxies, says Marc Postman, an astronomer with the Space Telescope Science Institute in Baltimore, Maryland. So maybe there are unrecognized galaxies out there, he says, "or some other source of light that we don't yet know what it is." [...] So where does the light come from? Perhaps, he says, there are far more small, faint dwarf galaxies and other faint regions on the outskirts of galaxies that instruments like the Hubble Space Telescope can't detect and so scientists just aren't aware of them. Or, maybe there's more dust out there interfering with the measurements than scientists expected. Or perhaps there's a more exotic explanation -- some unknown phenomenon out in the universe that creates visible light. It's even possible it's something associated with dark matter, a mysterious form of matter that exerts a gravitational pull on visible matter but has never been seen directly.

A group of astronomers from The University of Texas at Austin has revived an idea shelved by NASA to build a lunar liquid-mirror telescope on the moon to study the first stars in the universe. "The team, led by NASA Hubble Fellow Anna Schauer, will publish their results in an upcoming issue of The Astrophysical Journal," reports Phys.Org. From the report: These first stars formed about 13 billion years ago. They are unique, born out of a mix of hydrogen and helium gasses, and likely tens or 100 times larger than the Sun. New calculations by Schauer show that a previously proposed facility, a liquid mirror telescope that would operate from the surface of the Moon, could study these stars. Proposed in 2008 by a team led by Roger Angel of The University of Arizona, this facility was called the Lunar Liquid-Mirror Telescope (LLMT). NASA had done an analysis on this proposed facility a decade ago, but decided not to pursue the project. According to Niv Drory, a senior research scientist with UT Austin's McDonald Observatory, the supporting science on the earliest stars did not exist at that point. "This telescope is perfect for that problem," he said.

The proposed lunar liquid-mirror telescope, which Schauer has nicknamed the "Ultimately Large Telescope," would have a mirror 100 meters in diameter. It would operate autonomously from the lunar surface, receiving power from a solar power collection station on the Moon, and relaying data to satellite in lunar orbit. Rather than coated glass, the telescope's mirror would be made of liquid, as it's lighter, and thus cheaper, to transport to the Moon. The telescope's mirror would be a spinning vat of liquid, topped by a metallic -- and thus reflective -- liquid. (Previous liquid mirror telescopes have used mercury.) The vat would spin continuously, to keep the surface of the liquid in the correct paraboloid shape to work as a mirror. The telescope would be stationary, situated inside a crater at the Moon's north or south pole. To study the first stars, it would stare at the same patch of sky continuously, to collect as much light from them as possible. The team is proposing that the astronomical community revisit the shelved plan for a lunar liquid-mirror telescope, as a way to study these first stars in the universe.

An anonymous reader shares a report: Earthlings are lucky to live near a relatively stable Sun, which has enabled life on our planet to emerge and thrive over the past four billion years. While many worlds in our galaxy might contain the right ingredients to support life, though, a lot of them could be stuck with a more volatile star that prevents them from becoming -- or remaining -- habitable. To get a better grip on which types of star systems might be most likely to host aliens, a pair of scientists at New York University Abu Dhabi (NYUAD) Center for Space Science have observed space weather around nearly 500 stars, according to a study published on Sunday in the journal Monthly Notices of Royal Astronomical Society: Letters. The results suggest that planets subjected to occasional but intense flares are probably more hospitable to life than worlds that receive a constant flux of radiation and low-energy flares, which blows their protective atmospheres away. Planetary habitability "is one of the most important concepts in exoplanet science" and "is defined as the zone around a star in which a planet is able to sustain liquid water on its surface," said research scientist Dimitra Atri and graduate student Shane Carberry Mogan, both at NYUAD, in the study. "While this approach is useful to identify potentially hospitable planets around stars, it fails to take into account the damaging aspect of stellar activity on such planets," the pair added. "The main goal of this paper is to understand how stellar luminosity and flares can lead to atmospheric escape on [habitable zone] planets on long time-scales and how these losses impact planetary habitability."

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."

"Joe Biden, the projected winner of the U.S. presidency, will move to restore dozens of environmental safeguards President Donald Trump abolished," reports the Washington Post, "and launch the boldest climate change plan of any president in history."

destinyland shares their report: While some of Biden's most sweeping programs will encounter stiff resistance from Senate Republicans and conservative attorneys general, the United States is poised to make a 180-degree turn on climate change and conservation policy. Biden's team already has plans on how it will restrict oil and gas drilling on public lands and waters; ratchet up federal mileage standards for cars and SUVs; block pipelines that transport fossil fuels across the country; provide federal incentives to develop renewable power; and mobilize other nations to make deeper cuts in their own carbon emissions... Biden has vowed to eliminate carbon emissions from the electric sector by 2035 and spend $2 trillion on investments ranging from weatherizing homes to developing a nationwide network of charging stations for electric vehicles.

That massive investment plan stands a chance only if his party wins two Senate runoff races in Georgia in January; otherwise, he would have to rely on a combination of executive actions and more-modest congressional deals to advance his agenda.

Still, a number of factors make it easier to enact more-ambitious climate policies than even four years ago. Roughly 10% of the globe has warmed by 2 degrees Celsius (3.6 degrees Fahrenheit), a temperature rise the world has pledged to avoid. The price of solar and wind power has dropped, the coal industry has shrunk, and Americans increasingly connect the disasters they're experiencing in real time — including more-intense wildfires, hurricanes and droughts — with global warming. Biden has made the argument that curbing carbon will produce high-paying jobs while protecting the planet...

Some of the new administration's rules could be challenged in federal court, which have a number of Trump appointees on the bench. But even some conservative activists said that Biden could enact enduring policies, whether by partnering with Congress or through regulation... The new administration may be able to broker compromises with key industries that have experienced regulatory whiplash in the past decade, including the auto industry and power sector, while offering tax breaks for renewable energy that remain popular with both parties. And Biden can rebuild diplomatic alliances that will spur foreign countries to pursue more-ambitious carbon reductions...

Biden's advisers have said that they plan to elevate climate change as a priority in departments that have not always treated it as one, including the Transportation, State and Treasury departments. It will influence key appointments, affecting everything from overseas banking and military bases to domestic roads and farms.... Biden's pledge to achieve a carbon-free U.S. power sector within 15 years would mean the closing or revamping of nearly every coal- and gas-fired power plant around the country, and the construction of an unprecedented number of new wind turbines and solar farms. On top of that, engineers still need to devise a better way of storing energy when the sun is not shining or the wind is not blowing.

"If I were advising Biden on energy, my first three priorities would be storage, storage and storage," said Sen. Angus King, I-Maine, who worked in the alternative energy businesses before running for office.

Here's a good sign for alien hunters: More than 300 million worlds with similar conditions to Earth are scattered throughout the Milky Way galaxy. A new analysis [PDF] concludes that roughly half of the galaxy's sunlike stars host rocky worlds in habitable zones where liquid water could pool or flow over the planets' surfaces. From a report: "This is the science result we've all been waiting for," says Natalie Batalha, an astronomer with the University of California, Santa Cruz, who worked on the new study. The finding, which has been accepted for publication in the Astronomical Journal, pins down a crucial number in the Drake Equation. Devised by my father Frank Drake in 1961, the equation sets up a framework for calculating the number of detectable civilizations in the Milky Way. Now the first few variables in the formula -- including the rate of sunlike star formation, the fraction of those stars with planets, and the number of habitable worlds per stellar system -- are known. The number of sunlike stars with worlds similar to Earth "could have been one in a thousand, or one in a million -- nobody really knew," says Seth Shostak, an astronomer at the Search for Extraterrestrial Intelligence (SETI) Institute who was not involved with the new study.

Astronomers estimated the number of these planets using data from NASA's planet-hunting Kepler spacecraft. For nine years, Kepler stared at the stars and watched for the brief twinkles produced when orbiting planets blot out a portion of their star's light. By the end of its mission in 2018, Kepler had spotted some 2,800 exoplanets -- many of them nothing like the worlds orbiting our sun. But Kepler's primary goal was always to determine how common planets like Earth are. The calculation required help from the European Space Agency's Gaia spacecraft, which monitors stars across the galaxy. With Gaia's observations in hand, scientists were finally able to determine that the Milky Way is populated by hundreds of millions of Earth-size planets orbiting sunlike stars -- and that the nearest one is probably within 20 light-years of the solar system.

Most clocks are handled automatically by computers, points out Tora (Slashdot reader #65,882). So in lieu of daylight saving time, "what about shifting time each month, rather than twice a year?"

On Medium developer Brandon Gillespie offers the details of "Universal Solar Time." The clock is adjusted up by 10 minutes every month for the first six months, and then down by 10 minutes in the same manner, and can be offset by your timezone. The computerized systems can handle the time shift the same on the 1st...just like they currently do twice a year.

The benefit of such an automated system is the day cycle stays perceptibly the same — the sun is up roughly at the same period each day for any given month. While there are many challenges to such a system, such as what to do with all of the analog clocks, the advantages of a system like this should give all of the positive benefits of Daylight Savings, without the negative impact on a person's day.

"Its that time of year again," writes long-time Slashdot reader rufey: Millions of people around the world will be adjusting (or have already adjusted) their clocks... Over the years it is apparent that most people who have spoken about the twice-yearly clock change oppose it.

So I ask, why are we still changing clocks in the year 2020?
Long-time Slashdot reader thegreatbob believes the answer is: inertia. Personally, I am less opposed, and much more indifferent to its continued existence. One thing (arguably good) that it does do is provide distinct, specific temporal reference points that the gradual changing of seasons does not, by forcing people to take some sort of irregular action.

Do I think this in any way helps cancel out the harm caused by upsetting the sleep cycles of a huge portion of the population? Absolutely not.
But Slashdot reader Anonymouse Cowtard argues they're grateful for the time change — because "I was sick of the sun waking me at 5 a.m."

Since it is that time of year again, share your own thoughts in the comments.

And why do we keep setting our clocks back an hour?

NASA's Mars 2020 Perseverance rover mission has logged a lot of flight miles since being lofted skyward on July 30 -- 146.3 million miles (235.4 million kilometers) to be exact. Turns out that is exactly the same distance it has to go before the spacecraft hits the Red Planet's atmosphere like a 11,900 mph (19,000 kph) freight train on Feb. 18, 2021. From a report: "At 1:40 p.m. Pacific Time today, our spacecraft will have just as many miles in its metaphorical rearview mirror as it will out its metaphorical windshield," said Julie Kangas, a navigator working on the Perseverance rover mission at NASA's Jet Propulsion Laboratory in Southern California. "While I don't think there will be cake, especially since most of us are working from home, it's still a pretty neat milestone. Next stop, Jezero Crater." The Sun's gravitational influence plays a significant role in shaping not just spacecraft trajectories to Mars (as well as to everywhere else in the solar system), but also the relative movement of the two planets. So Perseverance's route to the Red Planet follows a curved trajectory rather than an arrow-straight path.

"Although we're halfway into the distance we need to travel to Mars, the rover is not halfway between the two worlds," Kangas explained. "In straight-line distance, Earth is 26.6 million miles [42.7 million kilometers] behind Perseverance and Mars is 17.9 million miles [28.8 million kilometers] in front." At the current distance, it takes 2 minutes, 22 seconds for a transmission to travel from mission controllers at JPL via the Deep Space Network to the spacecraft. By time of landing, Perseverance will have covered 292.5 million miles (470.8 million kilometers), and Mars will be about 130 million miles (209 million kilometers) away from Earth; at that point, a transmission will take about 11.5 minutes to reach the spacecraft.

Windows Central reports: Microsoft is preparing a major OS update for Windows 10 in 2021 that sources say will bring with it a significant design refresh to the Windows UI. I'm told that Microsoft is planning to update many top-level user interfaces such as the Start menu, Action Center, and even File Explorer, with refreshed modern designs, better animations, and new features. This UI project is codenamed "Sun Valley" internally and is expected to ship as part of the Windows 10 "Cobalt" release scheduled for the holiday 2021 season. Internal documentation describes the project as "reinvigorating" and modernizing the Windows desktop experience to keep up with customer expectation in a world driven by other modern and lightweight platforms.

Windows 10 has remained much the same these last few years, with little to no changes in its design or feature set. Many other platforms on the market have gone through entire redesigns or UI refreshes in the last five years, and while Windows 10 has gone through minor design iterations with the introduction of Fluent Design, we've not seen a significant refresh or rethinking of its UI. The Sun Valley project appears to be spearheaded by the Windows Devices and Experiences team, lead by Chief Product Officer Panos Panay, who took charge of said division back in February. Microsoft announced in May that the company would be "reinvesting" in Windows 10 in the 2021 timeframe, and my sources say that Sun Valley is the result of that reinvestment.