Phys.org is reporting this week that an international team of astrophysicists and planetary scientists has discovered a possible link between magnetospheric activity and ionospheric turbulence. In their study published in the journal Physical Review Letters, the group used data from two sources to compare magnetospheric activity and ionospheric turbulence occurring at nearly the same time.

As you know, the ionosphere comprises the upper reaches of Earth’s atmosphere—it spans from approximately 48 km to 965 km above sea level, holding ions formed from solar radiation, making it electrically charged. The magnetosphere is an area of space surrounding Earth—it has charged particles that are impacted by Earth’s magnetic field. It exists courtesy of the planet’s internal dynamo, and it extends to approximately 65,000 km from the surface, though the distance varies greatly depending on a variety of factors.

Scientists have long known that turbulence in the ionosphere can cause problems with GPS signals, radio communications and even parts of the internet. Researchers have been looking to understand better why it happens, to figure out a way to predict when it will occur, and how strongly. In this new effort, the research team has taken a step toward solving the latter problems.

The team suspected that activity in the magnetosphere might be responsible for at least some of the turbulence that occurs in the ionosphere. To investigate, they used two sources of observational data: one on activity in the ionosphere (from the Japanese spacecraft Arase) and the other on the magnetosphere (from the ground-based ICEBEAR station in Canada).

By comparing data from both over the period January 2020 to June 2023, they were able to see if activity happening in the magnetosphere was followed soon thereafter by turbulence in the ionosphere and found one such incidence.

Data from Arase showed a burst of activity on May 12, 2021, in the magnetosphere. Seconds later, data from ICEBEAR showed turbulence occurring in the ionosphere. The data also showed the activity for both occurred over roughly the same patch of Earth and that the shape and timing of the signals matched to what the team describes as “a high degree of precision.”

The researchers acknowledge that more work is required before a definitive association can be made between events in the magnetosphere and turbulence in the ionosphere, but they suggest their work is a strong step in proving it to be the case.

Popularmechanics.com has announced this week that a team of scientists announced the detection of dimethyl sulfide (along with a similar detection of dimethyl disulfide) in the atmosphere of an exoplanet called K2-18b. This is actually the second detection of dimethyl sulfide made on this planet, following a tentative detection in 2023. Their announcement was made in a paper published in Astrophysical Journal Letters.

Tons of chemicals are detected in the atmospheres of celestial objects every day. But dimethyl sulfide is different, because on Earth, it’s only produced by living organisms.

“It is a shock to the system,” Nikku Madhusudhan, first author on the paper, told the New York Times. “We spent an enormous amount of time just trying to get rid of the signal.”

It may sound surprising that the scientists were “trying to get rid of the signal,” but that’s exactly how detections like this work. Pretty much all of the exoplanets we’ve ever seen are simply too far away to just look at. Instead, to gather more information about what may lie on their surfaces, scientists observe the chemical makeups of their atmospheres.

This is done by capturing starlight that filters through those gaseous layers as a planet completes a transit in front of its host star. Different wavelengths of that starlight are blocked by different atmospheric chemicals, so by reading which wavelengths get filtered out as they pass through an exoplanets atmosphere, we can tell what that atmosphere is made of.

Astronomers have become very good at making these detections, but it’s still a difficult process. And the first step, every time, is to try to filter out noise—errant spikes in a spectrum that can disguise true detections—and false positives that might be caused by, say, a nearly invisible gas cloud in between us and an exoplanet.

So, when the astronomers spotted dimethyl sulfide in the atmosphere of K2-18b, they did everything to try to rule out the possibility that it was a ‘whoops.’

But even after carefully exhausting all the avenues they could think of over the course of two full observation sessions with JWST (which is rare in astronomy, considering how many teams want time with the coolest telescope we have) they found it impossible to attribute the detection to anything other than atmospheric composition. And if you rule out the impossible, whatever remains—however improbable—must be the truth.

May I end this shortened bulletin with a huge appeal to all you radio communicators who read this bulletin or listen to it, to consider sending me some news of your area? You will have noticed that, for months now, I’ve had virtually nothing to say about the South African Comms scene, or about events, activities or rescues that we have been involved in. Does that really mean nothing happens in South Africa? Please consider sending me as little as a paragraph from your area, and I will incorporate it in the bulletin. Thank you.

And now, bearing in mind which Sunday today is, may I warn you not to join the ranks of those in the statistics, to whom the following epitaph applies: “Death by Chocolate”!

This is Dave Reece ZS1DFR, hastily wiping the chocolate smears off all the keys on his keyboard, and reporting for HAMNET in South Africa.

Nasa.gov reports that NASA’s Deep Space Network facility in Canberra, Australia celebrated its 60th anniversary on March 19 while also breaking ground on a new radio antenna. The pair of achievements are major milestones for the network, which communicates with spacecraft all over the solar system using giant dish antennas located at three complexes around the globe.

Canberra’s newest addition, Deep Space Station 33, will be a 34-meter-wide multi-frequency beam-waveguide antenna. Buried mostly below ground, a massive concrete pedestal will house cutting-edge electronics and receivers in a climate-controlled room and provide a sturdy base for the reflector dish, which will rotate during operations on a steel platform called an alidade.

When it goes online in 2029, the new Canberra dish will be the last of six parabolic dishes constructed under NASA’s Deep Space Network Aperture Enhancement Program, which is helping to support current and future spacecraft and the increased volume of data they provide. The network’s Madrid facility christened a new dish in 2022, and the Goldstone, California, facility is putting the finishing touches on a new antenna.

The Deep Space Network was officially founded on Dec. 24, 1963, when NASA’s early ground stations, including Goldstone, were connected to the new network control center at the agency’s Jet Propulsion Laboratory in Southern California. Called the Space Flight Operations Facility, that building remains the centre through which data from the three global complexes flows.

The Madrid facility joined in 1964, and Canberra went online in 1965, going on to help support hundreds of missions, including the Apollo Moon landings.

By being spaced equidistant from one another around the globe, the complexes can provide continual coverage of spacecraft, no matter where they are in the solar system as Earth rotates. There is an exception, however: Due to Canberra’s location in the Southern Hemisphere, it is the only one that can send commands to, and receive data from, Voyager 2 as it heads south almost 21 billion kilometers through interstellar space. More than 24 billion kilometers away, Voyager 1 sends its data down to the Madrid and Goldstone complexes, but it, too, can only receive commands via Canberra.

“These new technologies have the potential to boost the science and exploration returns of missions traveling throughout the solar system,” said Amy Smith, deputy project manager for the Deep Space Network at JPL, which manages the network. “Laser and radio communications could even be combined to build hybrid antennas, or dishes that can communicate using both radio and optical frequencies at the same time. That could be a game changer for NASA.”

In Phys.org this week, I learned that Saccharin, the artificial sweetener used in diet foods like yogurts and sugar-free drinks, can kill multidrug-resistant bacteria—including one of the world’s most dangerous pathogens.

“Antibiotic resistance is one of the major threats to modern medicine,” said Professor Ronan McCarthy, who led the research at Brunel University of London’s Antimicrobial Innovations Center.

“Procedures such as tooth extractions and cancer treatment often rely on antibiotics to prevent or treat infection. But doctors are increasingly facing cases where the drugs no longer work.”

In 2019, antimicrobial resistance (AMR) killed 1.27 million people globally, with resistant infections contributing to nearly 5 million deaths.

Drug-resistant bacteria such as Acinetobacter baumannii, which causes life-threatening infections in people with a weakened immune system, and Pseudomonas aeruginosa, linked to chronic lung infections and sepsis, are on the World Health Organization’s list of top-priority pathogens.

“In exciting work led by our team, we’ve identified a novel antimicrobial— saccharin,” Prof McCarthy said. “Saccharin breaks the walls of bacterial pathogens, causing them to distort and eventually burst, killing the bacteria. Crucially, this damage lets antibiotics slip inside, overwhelming their resistance systems.”

Saccharin has been part of the human diet for longer than 100 years. While it has been extensively tested for safety in people, little was known about its effect on bacteria—until now with a study appearing in EMBO Molecular Medicine.

The international team found that saccharin both stops bacterial growth and disrupts DNA replication, and stops the bacteria from forming biofilms—sticky, protective layers that help them survive antibiotics.

This is very promising news in the world of life-threatening infections.

And techxplore.com is reporting on a new method of predicting where people lost in the wilderness may be found, based on simulations of their decision-making processes, which could help mountain rescue teams save lives in the future.

Researchers from the University of Glasgow have developed a sophisticated computer system to model the actions of simulated people lost in outdoor environments.

The system, which is based on data drawn from accounts of how people in the real world behaved after finding themselves lost outdoors, creates a “heat map” showing the probability of where missing people may be found in any landscape.

The Glasgow team hopes it could lead to the development of a robust new method to help search and rescue teams choose where to focus their recovery efforts, which could incorporate sensor-equipped drones to help scour the landscape.

In a new Early Access paper published in the journal IEEE Access, the team outlines how they used data from historical studies of how lost people behaved in real-world situations, to create simulated “agents” who act based on different psychological states.

The algorithms that underpin the agents are guided by distinct sub-models, each with a different goal in mind. They all seek to find their way back to civilization by heading for either water, trees, buildings, paths or roads. The simulated agents make decisions about where to go based on factors including their current location and whether they could see their preferred terrain.

To help inform the agents’ behavior, the team’s system also took into account data gathered on missing peoples’ likelihood of being found in different types of terrain, and the distances people typically traveled from their reported last known location.

The research is part of ongoing efforts at the University of Glasgow to use cutting-edge technology to bolster the work of search and rescue teams. Related research has used a data-driven approach to explore ways of making AI-controlled drones better at searching the countryside for missing people.

This is Dave Reece ZS1DFR, struggling to find his car keys in his house, let alone find lost souls in a strange environment, and reporting for HAMNET in South Africa.

Well, the death toll after Myanmar’s double earthquake last week stood at 3145 on Friday, but there are another 4000 or so souls unaccounted for, so this is not the end of the tragedy. Assistance has been slow in coming to Myanmar, and the rubble of many buildings has not yet been removed, so sadly the numbers are going to rise. Rescue teams continue to struggle to clear debris as the chances of finding any more injured but living victims decrease.

Riaan Greeff, ZS4PR, Regional Director for HAMNET in the Free States reports that The 30^th SASOL Marathon scheduled and planned for 29^th March 2025 was a huge success for both the Sasolburg Athletics club and the Sasolburg Radio club.

The Sasolburg Athletics club called for the radio support from the Sasolburg radio club.  The marathon event is a large event and leads to qualifying times towards the Comrades every year. And as happens every year, the seriousness of the call escalates to HAMNET being approached.

23 radio amateurs from three provinces went to Sasolburg on 28 and 29 March.

Gideon ZS4GJA was leading the logistical planning of this event, but due to a severe infection after a recent knee operation, had to withdraw medically and be booked in to a local hospital for an emergency procedure to address his leg.

Riaan, ZS4PR, HAMNET Director Free State, then took the reins to ensure the volunteers are catered for and the arrangement Gideon had in place could be adopted. 

Brian, ZS6YZ, the newly appointed National Director HAMNET, an active HAMNET leader for several years, also attended the race.  Family works together, and his daughter Anja ZS6SJC was also present. Like father like daughter…

The Gauteng and Limpopo members drove though on Friday afternoon and by Saturday morning 4am everyone was in attendance, ready to be deployed to strategic points all over Sasolburg.

Leon, ZS6LMG and Linda ZS6LML took responsibility to lead the athletes, and after the event, remarked that lead athletes are way more taxing than leading cyclists.  It was a first for this experienced couple. 

Ruan ZS6RFC and his wife Ilze-Mari ZS6IMF took the lead for the 10km group. 

The route was manned by several HAMNET members, focused on reporting the condition of athletes, summoning ambulance services, and giving feedback to the JOC, manned by Riaan ZS4PR, Jaco ZS6JCO and Wim ZS6WIM.  Inter-provincial people sitting in the same JOC does allow for excellent experiential learning.

Talking of learning and training, Pro-Ethnos, a fire brigade first responder training team lead by Jurie ZS6RIT from the West Rand was also called to use this event as a training opportunity.  Riaan instructed and allowed the young ladies Maryka ZS6MVS, Duemarie Swart and Nia Nel with their K9, Noala, to practice their communication skills by placing them in one of the more challenging areas in Sasolburg.  They had to relay their messages to a central person, who then relayed the messages to the JOC.  It was the first time they tried to work radio this way, and fared well, with many lessons learned.

By 13:00 the event was over, and the last athletes safe and accounted for.

Dolf Binneman, Chairman of the Sasol Marathon and Sasolburg Athletics club complemented the HAMNET team of radio amateurs for their professional and effective support they provided.  All his water-points and safety staff gave him positive feedback where HAMNET was involved to assist.

The Sasolburg and Vaal area have excellent radio repeater infrastructure in place.  UHF DMR and 2m FM repeaters were used as the main communication channels, and APRS via the digital packet repeater network provided real time tracking of the ham activities, the ambulances and the back marker vehicles.

Riaan thanks his team for a job well done, and I thank Riaan for the fine report.

Writing on camras.nl, a group of radio amateurs report that, on 22 March 2025, they used the Dwingeloo Radio Telescope successfully to bounce a radio signal off the surface of Venus. At the time, Venus was in its closest approach to Earth at about 42.000.000 km. Such a conjunction happens when Venus is between the Sun and the Earth, and happens approximately every 580 days.

‘Earth-Venus-Earth’ (EVE) bounces were extensively performed in the 60’s and 70’s to make radar images of Venus. More recently, in 2012, the Arecibo telescope in combination with the Green Bank telescope made a very detailed map of Venus. The first and, until now, only amateur EVE was achieved in 2009 by AMSAT-DL from the 20m Radio telescope at the Bochum Observatory (Sternwarte Bochum).

The Dwingeloo telescope was commanded to transmit a 278 second long tone at a frequency of 1299.5 MHz. Since the light travel time to Venus and back was about 280 seconds, they could receive the reflection of their own signal afterwards. They repeated this cycle four times.

While Dwingeloo received its own echo, the Stockert radio telescope, operated by Astropeiler Stockert e.V., also successfully received Venus’ echo of Dwingeloo’s signals. The receptions in Stockert were stronger than those received in Dwingeloo, since the Stockert receiving chain is a bit more sensitive.

The data analysis consists of correcting the received data for both the expected Doppler shift and the rate of change of this Doppler shift due to the rotations and relative motions of Earth and Venus. After channelizing the received signal in 1 Hz frequency bins, the echo of the transmitted signal should fall exactly in the predicted bin.

The preliminary analysis already shows a 5.4 sigma detection for Dwingeloo-Venus-Dwingeloo, an 8.5 sigma detection for Dwingeloo-Venus-Stockert, and a 9.2 sigma detection when combining the signals of Dwingeloo and Stockert.

They were planning to send complex modulated signals to perform more analysis on the correlations between transmitted and received signals. Unfortunately the transmitter, mounted in Dwingeloo’s focus box for the occasion, started failing after four successful transmissions. They therefore postponed the other experiments to the next Venus conjunction in October 2026.

In the preparation for this experiment, they collaborated with the Deep Space Exploration Society, who were also preparing an EVE experiment of their own, and the Open Research Institute. During the day of the experiment, they had a lot of help from present CAMRAS volunteers. A big thanks also goes to the volunteers of Astropeiler e.V. for observing with the Stockert telescope.

And thank you to camras.nl for that report.

This is Dave Reece ZS1DFR, wondering whether Venus is full of little pits from having radio signals bounced off her continuously, and reporting for HAMNET in South Africa.