Long-time Slashdot reader destinyland writes: Advent of Code isn't the only geeky tradition that's continuing in 2020. "This is going to be the first full year with Raku being called Raku," notes the site raku-advent.blog. "However, it's going to be the 12th year (after this first article) in a row with a Perl 6 or Raku calendar, previously published in the Perl 6 Advent Calendar blog." The tradition continues, with a new article about the Raku programming language every day until Christmas.

And meanwhile over at perladvent.org, the Perl Advent Calendar is also continuing its own article-a-day tradition (starting with a holiday tale about how Perl's TidyAll library "makes it trivial for the elves to keep their code formatting consistent and clean.")

But they're not the only ones. "Pandemic or not, Christmas time is a time for wonder, joy and sharing," writes Kristofer Giltvedt Selbekk from Oslo-based Bekk Consulting (merging technology with user experience, product innovation and strategy). So this year they're "continuing our great tradition of sharing some of the stuff we know every December" with 11 different advent calendar sites sharing articles (or, on one site, podcast episodes), on topics including JavaScript, Kotlin, React, Elm, functional programming, and cloud computing.

And if you're more interested in outer space, this also marks the 13th year for the official Hubble Space Telescope Advent Calendar. "Every day until Friday, December 25, this page will present one new incredible image of our universe from NASA's Hubble telescope," explains its page at the Atlantic.
There's also a series of daily coding challenges called "24 days of JavaScriptmas" at the tutorial site Scrimba, which has turned the event into a marketing opportunity by promising a $1,000 prize on Christmas Eve to one lucky participant chosen from the ones who publicized their solutions on Twitter.

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."

Amazon is laying the groundwork for a quantum computer, deepening efforts to harness technology that can crunch in seconds vast amounts of data that take even the most powerful supercomputers hours or days to process. From a report: Amazon has been hiring for a Quantum Hardware Team within its Amazon Web Services Center for Quantum Computing, according to internal job postings and information on LinkedIn. Marc Runyan, a former engineer with NASA's Jet Propulsion Laboratory, lists his title on the professional social network as senior quantum research scientist at Amazon and describes his role as "helping to design and build a quantum computer for Amazon Web Services." [...] Among Amazon's recent hires are research scientists focusing on designing a new superconducting quantum device as well as device fabrication. Developing its own quantum computer would let Amazon more closely mirror the approach taken by its major cloud rivals. International Business Machines first made a quantum computer available to the public in 2016 and has rolled out regular upgrades.

Long-time Slashdot reader SonicSpike brings some big news from outer space. European Space Agency announced this week that they're signing "a €86 million ($102 million USD) contract with an industrial team led by the Swiss start-up ClearSpace SA to purchase a unique service: the first removal of an item of space debris from orbit" in the year 2025.

"With this contract signature, a critical milestone for establishing a new commercial sector in space will be achieved..." In almost 60 years of space activities, more than 5,550 launches have resulted in some 42,000 tracked objects in orbit, of which about 23,000 remain in space and are regularly tracked. With today's annual launch rates averaging nearly 100, and with break-ups continuing to occur at average historical rates of four to five per year, the number of debris objects in space will steadily increase. ClearSpace-1 will demonstrate the technical ability and commercial capacity to significantly enhance the long-term sustainability of spaceflight...
"This is the right time for such a mission..." says Luc Piguet, founder and CEO of ClearSpace. [I]n the coming years the number of satellites will increase by an order of magnitude, with multiple mega-constellations made up of hundreds or even thousands of satellites planned for low Earth orbit to deliver wide-coverage, low-latency telecommunications and monitoring services. The need is clear for a 'tow truck' to remove failed satellites from this highly trafficked region...." Supported within ESA's new Space Safety programme, the aim is to contribute actively to cleaning up space, while also demonstrating the technologies needed for debris removal.

"Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water," says ESA Director General Jan Wörner. "That is the current situation in orbit, and it cannot be allowed to continue. ESA's Member States have given their strong support to this new mission, which also points the way forward to essential new commercial services in the future..."

"NASA and ESA studies show that the only way to stabilise the orbital environment is to actively remove large debris items. Accordingly we will be continuing our development of essential guidance, navigation and control technologies and rendezvous and capture methods through a new project called Active Debris Removal/ In-Orbit Servicing — ADRIOS. The results will be applied to ClearSpace-1. This new mission, implemented by an ESA project team, will allow us to demonstrate these technologies, achieving a world first in the process."

The ClearSpace-1 mission will target the Vespa (Vega Secondary Payload Adapter) upper stage left in an approximately 800 km by 660 km altitude orbit after the second flight of ESA's Vega launcher back in 2013. With a mass of 100 kg, the Vespa is close in size to a small satellite, while its relatively simple shape and sturdy construction make it a suitable first goal, before progressing to larger, more challenging captures by follow-up missions — eventually including multi-object capture. The ClearSpace-1 'chaser' will be launched into a lower 500-km orbit for commissioning and critical tests before being raised to the target orbit for rendezvous and capture using a quartet of robotic arms under ESA supervision. The combined chaser plus Vespa will then be deorbited to burn up in the atmosphere.

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."

To discard the theory of dark matter, "you'll need to replace it with something even more bizarre: a force of gravity that, at some distances, pulls massive objects together and, at other distances, pushes them apart." That's how Science magazine describes a new study, adding that "The analysis underscores how hard it is to explain away dark matter" — even though "after decades of trying, physicists haven't spotted particles of dark matter floating around." [T]o do away with dark matter, theorists would also need explain away its effects on much larger, cosmological scales. And that is much harder, argues Kris Pardo, a cosmologist at NASA's Jet Propulsion Laboratory, and David Spergel, a cosmologist at Princeton University. To make their case, they compare the distribution of ordinary matter in the early universe as revealed by measurements of the afterglow of the big bang — the cosmic microwave background (CMB) — with the distribution of the galaxies today....

Pardo and Spergel derived a mathematical function that describes how gravity would have had to work to get from the distribution of ordinary matter revealed by the CMB to the current distribution of the galaxies. They found something striking: That function must swing between positive and negative values, meaning gravity would be attractive at some length scales and repulsive at others, Pardo and Spergel report this week in Physical Review Letters. "And that's superweird," Pardo says...

In a paper posted in June to the preprint server arXiv, theoretical cosmologists Constantinos Skordis and Tom Zlosnik of the Czech Academy of Sciences present a dark matter-less theory of modified gravity they say jibes with CMB data. To do that, researchers add to a theory like general relativity an additional, tunable field called a scalar field. It has energy, and through Einstein's equivalence of mass and energy, it can behave like a form of mass. Set things up just right and at large spatial scales, the scalar field interacts only with itself and acts like dark matter...

Skordis's and Zlosnik's paper is "very exciting," Pardo says. But he notes that in some sense it merely replaces one mysterious thing — dark matter — with another — a carefully tuned scalar field. Given the complications, Pardo says, "dark matter is kind of the easier explanation."

While tonight will see SpaceX's 16th launch of its broadband satellites, that launch will also make history, reports CNET: The first stage of the Falcon 9 rocket is set to make its seventh flight, which would be a record for rocket recycling for the company. The booster previously flew on four Starlink missions and a pair of larger telecom satellite launches. SpaceX will likely attempt to land the booster on a droneship in the Atlantic shortly after launch and may also try to catch the two halves of the nose cone or fairing with another pair of ships.

This all happens just about 10 hours after SpaceX is scheduled to perform another big launch on the other side of the country. On Saturday morning [in just one half hour], another Falcon 9 will blast off from Vandenburg Air Force Base in California carrying the new NASA/European Space Agency Sentinel 6 Michael Freilich satellite designed to monitor global sea level rise and improve weather forecasting...

You can watch the whole thing right here.
SpaceX has also begun tweeting photos taken last weekend during its Crew Dragon capsule's flight from earth— and its arrival at the International Space Station.

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.

Four astronauts aboard their SpaceX Dragon capsule "Resilience" have arrived at the International Space Station, circling 262 miles above the Earth, where they will stay until spring. From a report: The capsule lifted off from the Kennedy Space Center Sunday evening atop a SpaceX Falcon 9 rocket, chasing the ISS for 27 hours before matching its altitude and speed for an orbital dock. The flight marks only the second crewed flight for Crew Dragon, which became the first commercial vehicle to put humans in orbit when astronauts Doug Hurley and Bob Behnken launched in May. "SpaceX, this is Resilience. Excellent job, right down the center," commander Hopkins radioed to mission control after the docking. "SpaceX and NASA, congratulations." The flight marks another milestone for SpaceX flying its first fully operational mission. After the May launch, designated "Demo-2" with Hurley and Behnken, NASA certified the capsule for operational use in its Commercial Crew program. The Resilience crew includes three NASA astronauts and one from the Japan Aerospace Exploration Agency who were mostly passengers during the flight of Crew Dragon, which generally flies without human input and docks to the ISS autonomously.

The big launch finally happens in 2 minutes. "All systems are go for tonight's launch at 7:27 p.m. EST of Crew Dragon's first operational mission with four astronauts on board," SpaceX tweeted this morning. But live coverage is already streaming on SpaceX's web site.

Space.com explains it's the first operational flight of SpaceX's "astronaut taxi," the Crew Dragon: Called Crew-1, this will be the second Crew Dragon mission to carry astronauts. NASA astronauts Michael Hopkins, Victor Glover and Shannon Walker, along with Japan Aerospace Exploration Agency astronaut Soichi Noguchi, will lift off from the historic Launch Complex 39A at NASA's Kennedy Space Center in Florida at 7:27p.m. EST (0027 GMT) to begin a six-month mission.
Space.com reports that the astronauts completed their 9-mile (14 km) drive to the Falcon 9 rocket on the launch pad inside a pair of Tesla's electric Model X SUVs.

In another report, CBS News has confirmed that SpaceX "plans to reuse the booster for the next Crew Dragon flight." NASA is counting on the Crew-1 flight and follow-on missions by SpaceX and Boeing to end the agency's sole reliance on Russian Soyuz spacecraft for trips to and from low-Earth orbit. NASA has spent $4 billion since 2006 buying seats aboard Soyuz spacecraft and another $6 billion to date on its Commercial Crew Program, ultimately awarding contracts to SpaceX and Boeing... With two successful test flights behind them, NASA engineers were able to certify the spacecraft after a detailed analysis of telemetry and inspections of the flight hardware. It was the first such certification since the space shuttle was being built in the 1970s and the first ever granted a commercially developed spacecraft.

"I believe 20 years from now, we're going to look back at this time as a major turning point in our exploration and utilization of space," said Phil McAlister, director of commercial spaceflight development at NASA Headquarters. "It's not an exaggeration to state that with this milestone, NASA and SpaceX have changed the historical arc of human space transportation...

The station's life support systems, including its water recycling equipment and carbon dioxide removal gear, have been beefed up to support a seven-member crew and additional stores and supplies have been laid in. But the U.S. segment of the station only has four crew "sleep stations" and Hopkins plans to bunk with a sleeping bag in the powered-down Crew Dragon.

Axiom Space has signed three private astronauts to join former NASA astronaut Michael Lopez-AlegrÃa on Ax-1, the first private mission into orbit and to the International Space Station. From a report: In March, Axiom Space announced plans to launch "history's first fully private human spaceflight mission to the International Space Station." The mission, dubbed Ax-1, would go forward using SpaceX's Crew Dragon vehicle to deliver private astronauts to the ISS for at least eight days. At the International Astronautical Congress last month, Axiom CEO Michael Suffredini said the company was aiming to launch in the fourth quarter of 2021. Details are still sparse. We know that former NASA astronaut Michael Lopez-AlegrÃa will be part of the mission, but the three other astronauts have not been announced yet. The promotional image Axiom posted Wednesday features three male silhouettes, suggesting there will be no female astronauts on board. There is some excitable chatter on Twitter and other places suggesting that two of the other astronauts might be actor Tom Cruise and director Doug Liman, who have been in talks with NASA about filming a movie on the ISS. NASA administrator Jim Bridenstine mentioned in June that Axiom was involved in those talks.

sciencehabit writes: Two years ago, a global dust storm veiled Mars. But although the storm took a toll, killing off NASA's Opportunity rover, it also revealed that such storms play an important role in how the once-wet planet loses its water. In 2014, looking back at data from 2007, scientists noticed that the fluorescent fog of hydrogen in the martian upper atmosphere faded as the southern hemisphere's summer ended and a previous global dust storm subsided. The only plausible source for that hydrogen was water. Subsequent observations have indicated that water, buoyed by storms, can reach much higher in the atmosphere than previously thought -- all the way to the ionosphere, a new paper reports. This allows charged particles to directly break the water apart, and it is likely the primary method of water loss on the planet today.

NASA administrator Jim Bridenstine says he plans to leave his position at the space agency under the new Joe Biden administration, even if he's asked to stay, according to an interview he did with Aviation Week. Bridenstine said the decision would be to ensure NASA has the right leader who connects with the new president. From a report: "What you need is somebody who has a close relationship with the president of the United States," Bridenstine told Aviation Week. "You need somebody who is trusted by the administration... including the OMB [Office of Management and Budget], the National Space Council and the National Security Council, and I think that I would not be the right person for that in a new administration." President Trump nominated Bridenstine, then a Republican representative from Oklahoma, to lead NASA in 2017. Bridenstine's confirmation became a contentious one, with many lawmakers decrying the idea of a politician running a scientific agency like NASA. "NASA is one of the last refuges from partisan politics," former Sen. Bill Nelson (D-FL) said during Bridenstine's confirmation hearing in November 2017. "NASA needs a leader who will unite us, not divide us. Respectfully, Congressman Bridenstine, I don't think you're that leader." Eventually, the Senate did narrowly confirm him in April 2018, with lawmakers voting along party lines.

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."

"Mark Kelly will soon be the fourth NASA astronaut to serve in the U.S. Congress," writes People magazine.

DevNull127 shares their report: In a tweet posted Wednesday, he said he was "deeply honored" to have been elected and to serve in the seat once held by the late Sen. John McCain. A retired U.S. Navy captain and astronaut, Kelly has flown in four space missions, including the final mission of Space Shuttle Endeavour in 2011. He is married to former Arizona Congresswoman Gabby Giffords, [who] was shot and nearly killed in 2011.

His identical twin Scott Kelly is also a retired astronaut. The two participated in NASA's landmark "twins study," in which Scott spent a year aboard the space station while scientists collected Mark's physiological data back home for comparison...

When he is sworn in, Kelly will be the only active member of Congress to have flown in space. He is preceded by three former NASA astronauts: former Sens. John Glenn and Jack Schmitt and Rep. Jack Swigert. Two other former members of Congress — Sen. Jake Garn and Rep. Bill Nelson — have flown in space as payload specialists. Apollo 13 astronaut John "Jack" Swigert was elected to the House of Representatives in 1982, but died of cancer before he could take office.
Saturday Kelly tweeted, "Congratulations to Joe Biden and Kamala Harris. We've got some challenges ahead of us, and I'm looking forward to working together to tackle them."

And the same day his brother Scott Kelly tweeted a memory about the moment he left the International Space Station after 500 days, "looked out the window of our space capsule at the truss, and was struck with awe at how we came together & accomplished this great feat.

"And that if we can do this, we can do anything if we commit ourselves and work together."

NASA has formally commented on a request by a US company to build a mega-constellation of satellites at an altitude of 720km above the Earth's surface, citing concerns about collisions. From a report: This appears to be the first time that NASA has publicly commented on such an application for market access, which is pending before the Federal Communications Commission. "NASA submits this letter during the public comment period for the purpose of providing a better understanding of NASA's concerns with respect to its assets on-orbit, to further mitigate the risks of collisions for the mutual benefit of all involved," wrote Samantha Fonder, an engineer for the space agency. At issue are plans put forth by AST & Science, which intends to build a constellation of more than 240 large satellites, essentially deploying "cell towers" in space to provide 4G and possibly 5G broadband connection directly to cell phones on Earth. The company, based in Midland, Texas, calls its constellation "SpaceMobile" and has raised an estimated $120 million.

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.

An anonymous reader shares a report: The Voyager 2 probe, one of NASA's most well-traveled spacecraft, has been unable to communicate with Earth for the past eight months. Voyager 2 has been wandering alone at the edge of interstellar space, gathering data some 11.6 billion miles from Earth and sending it back to us. But we haven't been able to pick up the phone and call back. The only radio antenna that can communicate with the probe, Deep Space Station 43 (DSS43) in Australia, has been offline while NASA completes a series of hardware upgrades. Some of the transmitters on DSS43 haven't been replaced for over 47 years, according to NASA. To test new hardware, the dish pinged Voyager 2 on Oct. 29 with a few commands. It was the first time since mid-March that a signal was beamed to the spacecraft. And because the probe is so far away, the communication team had to wait over 34 hours for a reply. Sure enough, Voyager 2 received the commands with no problems and sent back a "hello."

NASA's 322-foot rocket "Space Launch System" rocket "would be the most powerful rocket ever flown, eclipsing both the Saturn V that flew astronauts to the moon and SpaceX's Falcon Heavy," reports the Washington Post.

But "it's not the rocket's engines that concern officials but the software that will control everything the rocket does, from setting its trajectory to opening individual valves to open and close." Computing power has become as critical to rockets as the brute force that lifts them out of Earth's atmosphere, especially rockets like the SLS, which is really an amalgamation of parts built by a variety of manufacturers: Boeing builds the rocket's "core stage," the main part of the vehicle. Lockheed Martin builds the Orion spacecraft. Aerojet Rocketdyne and Northrop Grumman are responsible for the RS-25 engines and the side boosters, respectively. And the United Launch Alliance handles the upper stage. All of those components need to work together for a mission to be successful. But NASA's Aerospace Safety Advisory Panel recently said it was concerned about the disjointed way the complicated system was being developed and tested...

Also troubling to the safety panel was that NASA and its contractors appeared not to have taken "advantage of the lessons learned" from the botched flight last year of Boeing's Starliner spacecraft, which suffered a pair of software errors that prevented it from docking with the International Space Station as planned and forced controllers to cut the mission short. NASA has since said that it did a poor job of overseeing Boeing on the Starliner program, and has since vowed to have more rigorous reviews of its work, especially its software testing...

NASA pushed back on the safety panel's findings, saying in a statement that "all software, hardware, and combination for every phase of the Artemis I mission is thoroughly tested and evaluated to ensure that it meets NASA's strict safety requirements and is fully qualified for human spaceflight." The agency and its contractors are "conducting integrated end-to-end testing for the software, hardware, avionics and integrated systems needed to fly Artemis missions," it said.