The aurora borealis (and its southern equivalent, the aurora australis) is a fleeting and somewhat rare phenomenon that produces vivid curtains of color in the sky at extreme latitudes. It’s a common tourist activity to travel to areas where the aurora is more prevalent in order to catch a glimpse of it. The best opportunities are in the winter though, and since most people don’t want to spend hours outside on a cold night night in high latitudes, an all-sky camera like this one from [Frank] can help notify its users when an aurora is happening.
Because of the extreme temperatures involved, this is a little more involved than simply pointing a camera at the sky and hoping for the best. The enclosure and all electronics need to be able to withstand -50°C and operate at at least -30. For the enclosure, [Frank] is going with PVC tubing with a clear dome glued into a top fits to the end of the pipe, providing a water-resistant enclosure. A Raspberry Pi with a wide-angle lens camera sits on a 3D printed carriage so it can easily slide inside. The electronics use power-over-ethernet (PoE) rather than a battery due to the temperature extremes, which conveniently provides networking capabilities for viewing the images.
This is only part one of this build — in part two [Frank] is planning to build a system which can use this camera assembly to detect the aurora automatically and send out notifications when it sees it. Watching the night sky from the comfort of a warm house or sauna isn’t the only reason for putting an all-sky camera to use, either. They can also be used to observe meteors as they fall and then triangulate the position of the meteorites on the ground.
Sustained radio emissions originating from high over a sunspot are getting researchers thinking in new directions. Unlike solar radio bursts — which typically last only minutes or hours — these have persisted for over a week. They resemble auroral radio emissions observed in planetary magnetospheres and some stars, but seeing them from about 40,000 km above a sunspot is something new. They don’t seem tied to solar flare activity, either.
The signals are thought to be the result of electron cyclotron maser (ECM) emissions, which involves how electrons act in converging geometries of magnetic fields. These prolonged emissions challenge existing models and ideas about how solar and stellar magnetic processes unfold, and understanding it better could lead to a re-evaluation of existing astrophysical models. Perhaps even leading to new insights into the behavior of magnetic fields and energetic particles.
This phenomenon was observed from our very own sun, but it has implications for better understanding distant stellar bodies. Speaking of our sun, did you know it is currently in it’s 25th Solar Cycle? Check out that link for a reminder of the things the awesome power of our local star is actually capable of under the right circumstances.
How do you look back over your life and divide it up? Maybe by decades, cultural moments, or geopolitical events. For radio amateurs with older callsigns there’s a temptation to do so by solar cycles, as the roughly 11-year period of the Sun’s activity had a huge effect on radio propagation through the charge it creates in the upper atmosphere. We’re now in solar cycle 25, numbered since the 18th century when the science of solar observation began, and as never before we’re surrounded by information from experts such as [Dr. Tamitha Skov], the so-called [Space Weather Woman]. When she says something is on the way we listen, so a recent Tweet predicting a direct hit from a solar storm with a good probability of auroras in lower latitudes is very much worth sharing.
We must extend our commiserations to readers in equatorial climes and ever through the lower half of the USA, southern Europe, the Middle East, India, Japan, and China. You won’t see the aurora we’ll catch in Europe along with our friends in New Zealand, Canada, Russia, and northern USA. But even then to those of us at moderate latitudes an aurora is a pretty rare event, so we’re hoping for clear skies on the 2nd of February and would advise you to look out too if you’re in the likely zone even if they won’t be quite as impressive as those in our header picture. Meanwhile radio amateurs everywhere don’t have to see pretty lights in the sky to reap the benefits in terms of propagation, so happy DX hunting! The Tweet is embedded below the break, so you can play the timeline for yourselves.
Perhaps the best-known ridesharing service, Uber has grown rapidly over the last decade. Since its founding in 2009, it has expanded into markets around the globe, and entered the world of food delivery and even helicopter transport.
One of the main headline research areas for the company was the development of autonomous cars, which would revolutionize the company’s business model by eliminating the need to pay human drivers. However, as of December, the company has announced that it it spinning off its driverless car division in a deal reportedly worth $4 billion, though that’s all on paper — Uber is trading its autonomous driving division, and a promise to invest a further $400 million, in return for a 26% share in the self-driving tech company Aurora Innovation.
Playing A Long Game
Uber’s self-driving efforts have been undertaken in close partnership with Volvo in recent years.
Uber’s driverless car research was handled by the internal Advanced Technologies Group, made up of 1,200 employees dedicated to working on the new technology. The push to eliminate human drivers from the ride-sharing business model was a major consideration for investors of Uber’s Initial Public Offering on the NYSE in 2019. The company is yet to post a profit, and reducing the amount of fares going to human drivers would make it much easier for the company to achieve that crucial goal.
However, Uber’s efforts have not been without incident. Tragically, in 2018, a development vehicle running in autonomous mode hit and killed a pedestrian in Tempe, Arizona. This marked the first pedestrian fatality caused by an autonomous car, and led to the suspension of on-road testing by the company. The incident revealed shortcomings in the company’s technology and processes, and was a black mark on the company moving forward.
The Advanced Technology Group (ATG) has been purchased by a Mountain View startup by the name of Aurora Innovation, Inc. The company counts several self-driving luminaries amongst its cofounders. Chris Urmson, now CEO, was a technical leader during his time at Google’s self-driving research group. Drew Bagnell worked on autonomous driving at Uber, and Sterling Anderson came to the startup from Tesla’s Autopilot program. The company was founded in 2017, and counts Hyundai and Amazon among its venture capital investors.
Aurora could also have links with Toyota, which also invested in ATG under Uber’s ownership in 2019. Unlike Uber, which solely focused on building viable robotaxis for use in limited geographical locations, the Aurora Driver, the core of the company’s technology, aims to be adaptable to everything from “passenger sedans to class-8 trucks”.
Aurora has been developing self-driving technology to handle real-world situations since its founding in 2017. Being able to master the challenges of a crowded city will be key to succeeding in the marketplace.
Getting rid of ATG certainly spells the end of Uber’s in-house autonomous driving effort, but it doesn’t mean they’re getting out of the game. Holding a stake in Aurora, Uber still stands to profit from early investment, and will retain access to the technology as it develops. At the same time, trading ATG off to an outside firm puts daylight between the rideshare company and any negative press from future testing incidents.
The sun may be spotless, but that doesn’t mean it isn’t doing interesting things. A geomagnetic storm is predicted for this weekend, potentially giving those at latitudes where the Northern Lights are not common a chance to see a cosmic light show. According to SpaceWeather.com, a coronal hole, a gap in the sun’s atmosphere that can let the solar wind escape, is about to line up with Earth. The last time this hole was on the Earth-facing side of the sun, the resultant storm gave aurora as far south as Colorado. So if you’re in any of the northern tier states, you might want to find somewhere with dark skies and a good view to the north this weekend.
It’s not only space weather that’s in the news, but weather-weather too. Hurricane Dorian will probably make landfall as a Category 4 storm, probably along Florida’s Atlantic coast, and probably in the middle of the night on Monday. That’s a lot of uncertainty, but one thing’s for sure: amateur radio operators will be getting into the action. The Hurricane Watch Net will activate their net for Dorian on Saturday afternoon at 5:00 PM Eastern time, ready to take reports from stations in the affected area. Not a ham? You can still listen to the live feed once the net activates.
Hams aren’t the only ones getting geared up for Dorian, though. Weather satellite enthusiasts are pointing their SDRs at the sky and grabbing some terrifyingly beautiful pictures of Dorian as it winds up. Some of the downloaded images are spectacular, and if you’ve got an SDR dongle and a couple of pieces of coat hanger wire, you too can spy on Dorian from any number of satellites.
Speaking of which, over on r/RTLSDR, someone has done a little data mining and shown that NOAA 15 is still very much alive. u/amdorj plotted the scan motor current draw and found that it steadily decreased over time, possibly indicating that the bearings aren’t as worn as previously thought. We recently covered the story of the plucky satellite that’s almost two decades past its best-by date; here’s hoping our report on its death was greatly exaggerated.
We’ll finish up today with something not related to space. As Al Williams recently covered, for about fifty bucks you can now score a vector network analyzer (VNA) that will do all sorts of neat RF tricks. The NanoVNA sounds like a great buy for anyone doing RF work, but its low price point and open-source nature mean people are finding all kinds of nifty uses for it. One is measuring the length of coax cables with time-domain reflectometry, or TDR. Phasing antenna arrays? the NanoVNA sounds like the perfect tool for the job.
Imagine what it must have been like for the first human to witness an aurora. It took a while for our species to migrate from its equatorial birthplace to latitudes where auroras are common, so it was a fairly recent event geologically speaking. Still, that first time seeing the shimmers and ribbons playing across a sky yet to be marred by light pollution must have been terrifying and thrilling, and like other displays of nature’s power, it probably fueled stories of gods and demons. The myths and legends born from ignorance of what an aurora actually represents seem quaint to most of us, but it was as good a model as our ancestors needed to explain the world around them.
Our understanding of auroras needs to be a lot deeper, though, because we now know that they are not only a beautiful atmospheric phenomenon but also a critical component in the colossal electromagnetic system formed by our planet and our star. Understanding how it works is key to everything from long-distance communication to keeping satellites in orbit to long-term weather predictions.
But how exactly does one study an aurora? Something that’s so out of reach and so evanescent seems like it would be hard to study. While it’s not exactly easy science to do, it is possible to directly study auroras, and it involves some interesting technology that actually changes them, somehow making the nocturnal light show even more beautiful.
Google ‘Joan Feynman’ and you can feel the search behemoth consider asking for clarification. Did you mean: Richard Feynman? Image search is even more biased toward Richard. After maybe seven pictures of Joan, there’s an endless scroll of Richard alone, Richard playing the bongos, Richard with Arline, the love of his life.
Yes, Joan was overshadowed by her older brother, but what physicist of the era wasn’t? Richard didn’t do it on purpose. In fact, no one supported Joan’s scientific dreams more than he did, not even their mother. Before Richard ever illuminated the world with his brilliance, he shined a light on his little sister, Joan.
