RSID: <<2026-02-27T00:31Z MFSK-32 @ 9265000+1500>>
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Welcome to program 438 of Shortwave Radiogram.

I'm Kim Andrew Elliott in Arlington, Virginia USA.

Here is the lineup for today's program, in MFSK modes as noted:

  1:37 MFSK32: Program preview (now)
  2:48 MFSK32: Intricate silk helps spiders ensnare prey in webs
  6:36 MFSK64: Listening for radio signals from exoplanet
10:43 MFSK64: This week's images
28:30 MFSK32: Closing announcements


Please send reception reports to radiogram@verizon.net

And visit http://swradiogram.net

We're on Bluesky now: SWRadiogram.bsky.social

And X/Twitter: @SWRadiogram
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From Science News:

Intricate silk helps net-casting spiders ensnare prey in webs

Looped structures make webs that are both stretchy and
strong

By Emily Conover
February 24, 2026

For spiders that fling their webs at prey, a sturdy net is
essential.

A net-casting spider in search of a meal dangles upside down,
holding a web in its legs before launching it at an unsuspecting
insect. In the process, parts of the web can stretch to up to 24
times their original size in about a tenth of a second without
breaking.

The web of the rufous net-casting spider (Asianopis subrufa)
pulls off that feat thanks to looping strands that surround a
stretchy silk core, researchers report in the Feb. 3 Proceedings
of the National Academy of Sciences. Scanning electron microscope
images revealed the spider silk’s intricate structure.

For most materials, there’s a tradeoff: Substances that stretch
tend to break more easily. But the webs of these spiders manage
to be both strong and stretchy.

As a strand stretches, the loops straighten, and those threads
reinforce the core and prevent it from breaking. The spiders
customize the amount of coiling in different sections of the web
to account for how much each portion needs to stretch. The spider
extrudes the loops of silk from a different set of glands than
the core fiber, producing a sturdy material.

The resulting fibers are beautiful — but deadly.

https://www.sciencenews.org/article/silk-net-casting-spiders-prey-web
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Image: The silk of the rufous net-casting spider, shown in a
scanning electron microscope image, is simultaneously strong and
stretchy, thanks to the loops of silk on its surface ...

Sending Pic:304x140;

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Shortwave Radiogram now changes to MFSK64 ...


 

RSID: <<2026-02-27T00:36Z MFSK-32 @ 9265000+1500>>
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This is Shortwave Radiogram in MFSK64

Please send your reception report to radiogram@verizon.net
 

From Phys.org:

Are there aliens broadcasting from Hycean world K2-18b?
Astronomers just listened in

by Andy Tomaswick, Universe Today
February 24, 2026

If you've been following exoplanet research over the last couple
of years, you've definitely heard of K2-18b. Located 124 light
years away in the constellation Leo, it's attracted a lot of
attention as it sits squarely in its red dwarf host star's
habitable zone, and measurements of the James Webb Space
Telescope show its atmosphere is rich in carbon dioxide and
methane. It's one of the prime candidates for a "Hycean"
world—one where a thick hydrogen-rich atmosphere covers a global
liquid water ocean.

It is such an intriguing target for Search for Extraterrestrial
Intelligence (SETI) researchers that they turned two of the most
powerful radio telescopes in the world to watch K2-18b's system.
A recent paper, available on the arXiv preprint server, shows
that there is likely no artificial narrow-band radio signals that
are equivalent to our technology level coming from the planet,
despite millions of potential hits.

Capturing the data necessary to process this not only involved
the Karl G. Jansky Very Large Array (VLA) in New Mexico, but also
the MeerKAT radio telescope in South Africa. These are two of the
most powerful radio telescopes on the planet, and having them
coordinate like this on an observational campaign is exceedingly
rare.

But it wasn't just the physical hardware that was important for
this work—the "data pipeline," as astronomers call the software
filters and logic that come after the data is collected, is
equally as critical, especially in radio astronomy. Earth-based
signals are the source of the vast majority of radio signals
these telescopes pick up, and advanced filtering algorithms, such
as the Commensal Open-Source Multi-Mode Interferometer Cluster
system that the VLA used and the Breakthrough Listen User
Supplied Equipment (BLUSE) system that MeerKAT used, are critical
pieces of any modern-day radio astronomy program.

The logic of that filtering is still the responsibility of the
humans in the loop, though, and the paper describes five
different constraints they imposed on the data to screen for
potential alien technosignatures. First was RFI
masking—essentially they removed all data from signals that fell
within frequency bands that were known to be heavily contaminated
by terrestrial interference. If the aliens were talking on those
channels, we'll have to use some other method—like a radio
telescope on the far side of the moon—to hear them.

Doppler effects, like those that change how an ambulance sounds
when it approaches or passes you, are even more prominent when
the signal is passing between planets. Any signal with
essentially no Doppler change was eliminated outright, as it
could only have come from Earth. Perhaps the most debatable
logical filtering choice was to eliminate all signals with a
signal-to-noise ratio of less than 10 or more than 100. While
this eliminated extremely weak false positives, as well as strong
instrumental data artifacts typically only seen in one antenna,
it could also have eliminated relatively weak actual signals.

Another filtering technique is to use multibeam analysis. In this
instance, the telescopes formed coherent "beams" across the sky,
with one pointing directly at K2-18b and the other pointing
elsewhere. In these cases, a signal coming from the exoplanet
would have appeared only in the beam pointed directly at it,
while Earth-bound interference bleeds into multiple beams
simultaneously. A final check, which wasn't necessary due to the
timing of the survey, is transit filtering. Any signal that
appears from K2-18b should go away when the planet passes behind
its parent star, but since it didn't have such a "secondary
transit" during the observational window, no such filtering was
necessary.

In short, despite millions of potential signals throughout the
observational window, none passed these filters. There were no
definitive technosignatures in the narrowband radio spectrum from
K2-18b. While that might sound disappointing, it's exactly the
kind of thing that science needs to advance. By thoroughly
scanning the planet and finding nothing, they are able to place
"upper bounds" on the power of a transmitter from that system—in
terms of power it would be something equivalent to the collapsed
Arecibo radar in Puerto Rico. If there is a civilization there,
they certainly aren't shouting at us with anything larger than
that level of radio telescope.

Perhaps the most important result, though, is the proof of
concept for their automated filtering system. Processing the
millions of signals the two telescopes discovered by hand would
have been next to impossible. So when even larger radio
telescopes, like the Square Kilometer Array, come online, these
techniques will be ready to help another survey make sense of the
mass of data it collected. While K2-18b might be quiet today, we
will continue to get much better at listening, if it ever does
start to speak to us.

https://phys.org/news/2026-02-aliens-hycean-world-k2-18b.html
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This is Shortwave Radiogram in MFSK64

Please send your reception report to radiogram@verizon.net
 

This week's images ...
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Alexander Girard fabrics for Michigan-based Herman Miller
Furniture. tinyurl.com/2a5jvrbc ...

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Manhattan's Lower East Side in the snow, February 22.
tinyurl.com/28xt8mnp ...

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Lightning strikes during a thunderstorm in Montevideo, Uruguay
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https://x.com/thandojo/status/2026999135291985954

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Children in Mejicanos, El Salvador, look at a mural made of
plastic bottle caps by Venezuelan artist Oscar Olivares.
tinyurl.com/253r2kpy ...

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In Kuwait City, pigeons fly over buildings as the sun rises.
tinyurl.com/253r2kpy ...

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Close-up of snowdrops in Galashiels, Scotland. tinyurl.com/24d75fu9
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The Grieg Street Bridge in Inverness, Scotland, at night.
tinyurl.com/24d75fu9 ...

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A street in Providence, Rhode Island, after the recent historic
snowfall. tinyurl.com/2adqo66u ...

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Sunrise over the Basilica of the National Shrine in Washington
DC, February 24. tinyurl.com/24ho43yu ...

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Our painting of the week is "Braddock Plumes" (2023) by Ron
Donoughe (American, b.1958). tinyurl.com/2cfdufvv ...

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Shortwave Radiogram returns to MFSK32 ...

 

RSID: <<2026-02-27T00:58Z MFSK-32 @ 9265000+1500>>

This is Shortwave Radiogram in MFSK32 ...


Transmission of Shortwave Radiogram is provided by:

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and

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Please send reception reports to radiogram@verizon.net

And visit http://swradiogram.net

http://swradiogram.bsky.social

X/Twitter (for now): @SWRadiogram

I'm Kim Elliott. Please join us for the next Shortwave
Radiogram.



 

RSID: <<2026-02-27T11:30Z MFSK-64 @ 15770000+1500>>

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Cynthia “Cindy” Wilson of the B-52s was born on February 28, 1957.


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https://www.b52cindywilson.com/

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