The New York Times reported today that you would need HALF A MILLION high definition TVs to display just one image from the Roman Space Telescope in full. Wow.
This quote is obviously about telescopes, but I think in many ways it applies to homebrew radio. We sometimes use the term "first light" to describe the first signals heard through a new homebrew receiver. That term comes from astronomy, and is used to describe the first light seen through a new telescope. I think there are strong parallels with homebrew radio.
In 2016 Paul Horowitz talked about SETI at Google. Fascinating stuff. Paul did an especially good job of weaving in a lot of radio/electronic and computer info.
-- I was pleased to learn that one of the early radio astronomy antennas used plywood covered with copper. I hope it was copper tape!
-- I didn't know that the Fast Fourier Transform was something developed in the 1960s.
-- Parkes Telescope! Yea!
-- Paul's "chirping" of receivers to screen out targets that are NOT doppler shifting (i.e. terrestrial signals).
-- Paul tells the group that "amateur" does not mean unprofessional -- it means that the person is doing it for the love of doing it. Amen.
-- SETI at Home.
-- Tube op-amps! (was that two 12AX7s?)
-- A variometer! Wow! I have two here -- one in the ET-2 regen receiver (a gift from Pericles HI8P), and another that I homebrewed using a 35mm film can.
The Scientific American video (above) has some really interesting info on how they built the JWST and what its capabilities are. For example, they tell us that it could detect the heat from a single bumble bee at the distance of the surface of the moon. How the mirror was made, and how it is adjusted in space is really amazing.
The Scientific American article provides a good, balanced view of how the initial results from JWST are calling into question the basic models of cosmology:
NASA’s James Webb Space Telescope has produced the deepest and sharpest infrared image of the distant universe to date. Known as Webb’s First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail.
Thousands of galaxies – including the faintest objects ever observed in the infrared – have appeared in Webb’s view for the first time. This slice of the vast universe is approximately the size of a grain of sand held at arm’s length by someone on the ground.
It is good every once in a while to step back from our electronic work benches and take a look at what other kinds of builders are making. Hack-A-Day led me to this wonderful video from Holland. There is great background information on telescopes, but the really great part is the interview with the Dutch fellow who is actually making -- in his home workshop -- these tiny telescopes. Icing on the cake: One of them will be used in a student Cube-Sat project in Oregon.
Be sure to stay to the end for an intriguing presentation by Dr. Liam Fullersheit.
These are some of the drawings that I made during the Mars 2020 opposition. I would go out to my back porch with my 6 inch Dobsonian Newtonian telescope. I would look closely at Mars, making mental note of what I was seeing. Then I would go to the shack and immediately draw what I'd seen. I would then look for relatively recent images of Mars made by people with more experience and better equipment, and I'd compare my drawings with their images -- this enabled me to understand what I was seeing. Also useful was the Mars Profiler of Sky and Telescope magazine -- you just plug in the date and time and it displays the part of Mars that is facing us.
I was especially pleased with the drawing and image above because I'd been reading a lot about the Hellas impact crater in Kim Stanley Robinson's Mars Trilogy. (SCP should be SPC = Southern Polar Cap.)
I came to think of this as the "M of Mars." I think it is just Mare Cimmerium, Mare Hesperia, and Mare Tyrrhenum.
bcastropics.com made this illustration of how Mars's apparent size has changed
Sometimes waking up a bit earlier when the sunrise is coming later leads you to some interesting things.
It was quite humid in Northern Virginia on the morning of 25 August 2020, but the skies were surprisingly clear. I stepped outside at about 0500 local time, coffee cup in hand. Venus was blazing in the east. Then I saw this big very bright red thing high in the southern sky. It seemed almost too bright and too high in the sky to be Mars. But a quick check with Stellarium showed that it was in fact the Red Planet. I pulled out my six inch Dobsonian reflector telescope and soon had Mars in the eyepiece. For the first time in many years I could see surface features: It is springtime in the southern hemisphere of Mars, but the Southern Polar Cap (which recedes in the summer) was still very prominent (in my eyepiece it was near the top, as in the GIF above) . I could also see an albedo (dark on light) feature below the icecap. I went out again on the morning of 26 August 2020. Again the Southern Polar Cap was very visible. Below it, near the center of the disc, I could make out a large albedo feature. I am pretty sure that is Mare Erythraeum.
Above is what Stellarium presented as Mars as viewed from Earth this morning. The Southern Polar Cap is much more prominent in my telescope (you can see it in the upper right in the image above). The large dark thing near the center of the disc is Erythraeum. In the Stellarium image you can see the enormous Vallis Marinaris canyon shooting off to the lower right (sadly I could not see this in my telescope).
The GIF at the top of this post gives a much better view than I get with my little six inch telescope. The GIF gives a good idea of what the albedo features and the ice cap look like. This was a great time for me to see these things. I'm almost done with the second book in Kim Stanley Robinson's Mars Trilogy -- much of the story takes place in sanctuaries carved under the Southern ice cap, and in Hellas (which Robinson's colonists are filling with water). During the 2018 Earth-Mars opposition a big dust storm made it impossible for me to see anything on Mars; a similar storm takes place during book one of Robinson's Trilogy. And right now the Perseverance rover is on its way to Mars. This 2020 opposition will be the best one until 2033. So don't miss it.
Above: Transit of Mercury, November 11, 2019 as I saw it from Northern Virginia using a 4.5 inch reflector with image projected onto a white paper. Elisa took the picture with her I-phone. Arrow shows Mercury. I almost missed it -- Billy texted from college to remind me of the big event.
Above: Transit of Venus June 6, 2012 as seen from Northern Virginia. Billy (age 13) took the picture with his I-phone 4. Venus is much bigger, much closer and much easier to see. Near the bottom edge of the solar disc.
Above; Billy on November 12, 2011 with the 4.5 inch Tasco Reflector that was used on BOTH the Venus and Mercury transits (we projected the image on paper). On this day we were using our newfound solar photography expertise to take a picture of sunspots (our picture below).
Ah, those were the days! Many spots back then. None now.
Above you can watch a video showing the legendary John Dobson making a big telescope. Born in Beijing, Dobson is the former Hindu monk who left the monastery to show people how to make big telescopes out of shipping tubes and port-hole glass. Think of it as the BITX of amateur astronomy. Dobson is the founder of the "sidewalk astronomy" movement -- that's when you set up your 'scope on an urban sidewalk and show the wonders of the universe (or at least the solar system) to passers-by. We did this in London with Saturn. (Some of the cynical Londoners couldn't believe it was real -- they thought I had a transparency in the scope tube.) Dobson developed a very simple and popular method of mounting telescope tubes -- the "Dobsonian" method. More on Dobson here: https://en.wikipedia.org/wiki/John_Dobson_(amateur_astronomer)
Below you can see a short update on Peter's homebrew airplane.
Damn. Just as Mars gets close enough for me to see something with my 6 inch reflector telescope, a massive dust storm hits. I was out there this morning at 0430 local. Mars was bright and red in the southern sky, but when I got it in the telescope's field of view it was like looking at a red version of Venus -- just the disk, with no surface features visible. The before-and-after pictures above (taken with far better equipment than mine) shows the extent to which the dust has obscured things on Mars.
But Sky and Telescope reports that the Martian skies may soon be clearing. Hooray!
That's the Russian radio-telescope that picked up what was thought to be a possible signal from an extraterrestrial civilization. This article from the SETI Institute has some interesting tech info on antennas and power levels. Definitely not QRP!